DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

United States Earthquakes, 1976

By

Jerry L. Coffman

and

Carl W. Stover

Open-File report 84-976

Prepared in cooperation with National Oceanic and Atmospheric Administration,

This report has not been reviewed for conformity with U.S. Geological Survey editorial standards.

1984

Contributors

Contributors to this publication are listed below according to the type of data supplied or service performed.

Hypocenters and magnitudes: John S. Derr, U.S. Geological Survey W. LeRoy Irby, U.S. Geological Survey R. Kangas, U.S. Geological Survey Waverly J. Person, U.S. Geological Survey Bruce W. Presgrave, U.S. Geological Survey Hawaiian Volcano Observatory, U.S. Geological Survey

Intensities: Jerry L. Coffman, NOAA, EDIS Ruth B. Simon, U.S. Geological Survey

Geodesy: B.K. Meade, NOAA, NOS, National Geodetic Survey John G. Gergen, NOAA, NOS, National Geodetic Survey

Tsunamis: Mark G. Spaeth, NOAA, National Weather Service

Strong-motion seismograph data:

Ronald L. Porcella, U.S. Geological Survey

Well-water levels:

Kenneth L. Rennick, U.S. Geological Survey

Computer programs, editorial assistance, and manuscript review:

Beverly Armstrong, NOAA, EDIS Sharon R. Johnson, NOAA, EDIS Leslie D. Morris, NOAA, EDIS Carl A. von Hake, NOAA, EDIS Carol Weathers, NOAA, EDIS

111

Contents

Page Contributors ...... iii Introduction ...... 1 Discussion of Tables ...... 1 Epicenter Maps ...... 1 Earthquake Information Services ...... 1 Magnitude and Intensity Ratings ...... 3 Modified Mercalli Intensity Scale ...... 5 Acknowledgments ...... 6 Earthquake Descriptions ...... 7 Alaska ...... 7 Arizona ...... 10 Arkansas ...... 12 California ...... 15 Connecticut ...... 29 Georgia ...... 29 Hawaii ...... 29 Idaho ...... 41 Indiana ...... 41 Kentucky ...... 41 Maine ...... 43 Massachusetts ...... 43 Michigan ...... 43 Missouri ...... 43 Montana ...... 44 Nevada ...... 44 New Jersey ...... 45 New Mexico ...... 46 Oklahoma ...... 47 Oregon ...... 48 Puerto Rico ...... 49 Rhode Island ...... 49 Tennessee ...... 49 Texas ...... 50 Utah ...... 50 Virginia ...... 50 Virgin Islands ...... 51 Washington ...... 52 West Virginia ...... 55 Wyoming ...... 56 Miscellaneous Activities ...... 71 Horizontal Control Surveys for Crustal Movement Studies ...... 71 Vertical Movement Studies...... 71 Tsunamis ...... 71 Principal Earthquakes of the World ...... 71 Fluctuations in Well-Water Levels ...... 72 Strong-Motion Seismograph Data ...... 83 Introduction ...... 83 Accelerograph Data ...... 83 Intensities Observed in States Beyond Epicentral Region ...... 93 References ...... 94 LIST OF TABLES

Table Page 1 Summary of earthquakes felt in U.S. for 1976 ...... 58 2 Principal earthquakes of the world during 1976 ...... 73 3 Earthquake fluctuations in well-water levels during 1976 ...... 76 4 Earthquakes in 1976 believed to have caused fluctuations in well-water levels ...... 80 5 Summary of U.S. accelerograph records recovered during 1976 ..... 85 6 Summary of non-U.S. accelerograph records recovered during 1976 ... 91

LIST OF ILLUSTRATIONS

Figure Page 1 Earthquake epicenters in the U.S. in 1976 ...... 2 2 Earthquakes plotted by Modified Mercalli Intensity in 1976 ...... 4 3 Area affected by western Arizona earthquake of February 4 ...... 11 4 Area affected by northeastern Arkansas earthquake of March 25 ... .13 5 Area affected by southern California earthquake of January 1 .... .16 6 Area affected by southern California earthquake of April 8 ...... 18 7 Area affected by southern California earthquake of August 11 ..... 22 8 Area affected by southern California earthquake of October 17 .... 24 9 Area affected by southern California earthquake of November 4 .... 25 10 Area affected by southern California earthquake of November 22 .... 27 11 Area affected by northern California earthquake of November 26 .... 28 12 Area affected by Hawaii earthquake of April 2 ...... 32 13 Area affected by eastern Kentucky earthquake of January 19 ...... 42 14 Area affected by southern Quebec, Canada, earthquake of October 23 . .43 15 Area affected by northwestern New Mexico earthquake of Janaury 5 ... 46 16 Area affected by northern Oregon earthquake of April 13 ...... 48 17 Area affected by Virginia-North Carolina border earthquake of September 13 ...... 51 18 Area affected by Vancouver Island earthquake of May 16 ...... 53 19 Area affected by northwestern Washington earthquake of September 2 . . 54 20 Area affected by northwestern Washington earthquake of September 8 . . 55

vi United States Earthquakes, 1976

Jerry L. Coffman, NOAA, Environmental Data and Information Service Carl W. Stover, U.S. Geological Survey

Introduction This publication describes all earthquakes two-tenths of a degree or less, depending on their that occurred in the United States and nearby continental or oceanic location. The oceanic territories in 1976. It has been produced jointly hypocenters are less accurate than those on the by the NOAA Environmental Data and Information continent, even though both are listed to two Service (EDIS) and the U.S. Geological Survey decimals. Depths are listed to the nearest whole (USGS). Its purpose is to provide a continuous kilometer, but may not be fcnown to this accuracy. history of U.S. earthquakes for studying seismic risk, evaluating nuclear powerplant sites, design­ Magnitude values listed in the tables were ing earthquake-resistive structures, and answering furnished by cooperating institutions or inquiries from the scientific and general public. determined by USGS. The computational sources are labeled according to the assigned letter codes The publication is composed of three major shown in footnotes to the tables. The absence of chapters: Earthquake Descriptions (which includes a letter code in the magnitude column of table 1 a chronological list of earthquakes by state in indicates that the epicenter source listed in the 1976 (table 1) and a summary of macroseismic "source" column is also the magnitude source. If data reported for each earthquake); Miscellane­ a letter code does not appear in the "source" ous Activities (which contains information on column, the earthquake is noninstrumental. crustal movement studies, tsunamis, principal earthquakes of the world (table 2), and fluc» tuations in well«-water levels (tables 3 and 4)); and Strong-Motion Seismograph Data (table 5). EPICENTER MAPS The intensity and macroseismic data in "Earthquake Descriptions" are compiled from questionnaire Figure 1 is a computer plot of all earthquake canvasses (see next paragraph), newspaper epicenters listed in table 1. Each earthquake is articles, and reports prepared by other government organizations, state institutions, local indicated by a small dot. organizations, and individuals. Each description Figure 2 is a computer plot of 1976 earth­ includes date, origin time, hypocenter and quakes by Modified Mercalli intensity. Maximum hypocenter source of the earthquake, magnitude, intensities are represented by Arabic numerals at maximum intensity (Modified Mercalli), and the location that each occurred. Earthquakes macroseismic effects reported in the area. of int. I-IV are represented by dots. The USGS collects macroseismic intensity information primarily by mailing questionnaires, The selection of intensity or isoseismal maps "Earthquake Report" forms, to postmasters in the (figs. 3-20) is governed largely by the size of earthquake area. Postmasters complete the forms the area affected. This means that sharp, and return them to USGS, where they are evaluated localized shocks of intensity VI (which occur and intensities are assigned. The USGS publishes mostly in California) may not be represented by preliminary intensity data in its quarterly these maps, whereas other earthquakes of Circular, Earthquakes in the United States. The intensity V and VI (which occur largely in the final information is published- in the United Eastern and Central States) often will be States Earthquakes series, issued annually since illustrated because of the larger felt areas. Numerals on these computer-plotted maps represent the maximum MM intensities at each town. Isoseismal contours are a generalization of intensity data and are extrapolated to regions DISCUSSION OF TABLES that have no observations. The contours do not include each intensity observation. The earthquake values in tables 1, 2, 4, and 5 include date, origin time, hypocenter (epicenter and focal depth), and magnitude (table 1 also contains the Modified Mercalli (MM) intensity). EARTHQUAKE INFORMATION SERVICES The origin time and date are listed in Universal Coordinated Time (UTC). The epicenters were taken from those published in the USGS Preliminary The National Geophysical and Solar- Determination of Epicenters Monthly Listing or Terrestrial Data Center (NGSDC), one of the five Earthquakes in the United States. The accuracy of major facilities of NOAA's Environmental Data the epicenters in table 1 is that claimed by the and Information Service, is responsible for data institution supplying the hypocenter and is not activities in seismology. Its services include necessarily the accuracy indicated by the number preparing local and regional seismic histories for of decimals listed. The epicenters located by engineers, actuaries, and other scientists and USGS have a varying degree of accuracy, usually answering direct inquiries from the public on all National Oceanic and Atmospheric Administrat Environmental Data S«rv 1976 Figure 1.--Earthquake epicenters in the U.S. in 1976 aspects of historical earthquakes. Additional as adopted by the International Association of services and products include publishing annual Seismology and Physics of the Earth's earthquake summaries and revised- historical earth­ Interior (IASPEI; Bath, 1966, p. 153), where quake reports; and making available copies of A is the maximum horizontal surface-wave ground seismograms, accelerograms, displacement meter re­ amplitude in micrometers; T is the period in cords, digitized strong-motion seismograms, and seconds, and 18

Intensity, as applied to earthquakes, MAGNITUDE AND INTENSITY RATINGS represents a quantity determined from the effects on people, manmade objects, and the Earth's Magnitude, a measure of the "size" of an surface (landslides, ground fissures). earthquake, is roughly related to the energy Intensities are assigned according to the release at the focus of an earthquake. Although descriptions listed in the Modified Mercalli the magnitude scale has neither "top" nor "bottom" Intensity Scale of 1931 (see next section). There values, the highest ever recorded was magnitude are 12 discrete steps in the MM scale. An 8.9 and the lowest about -3. On this earthquake in a populated area will have different logarithmic scale, a magnitude 6 shallow-focus intensities at different localities, owing to earthquake represents elastic-wave energy the distance from the epicenter of the earthquake, approximately 30 times greater than that generated local geological conditions, structural design by a magnitude 5 earthquake, 900 times greater of buildings, and the earthquake magnitude. than that of a magnitude 4 shock, and so forth. Many factors enter into the determination of The text of this publication gives the earthquake magnitude, including earthquake focal intensity for each city where the earthquake was depth, frequency content of the sampled felt and summaries of the strongest effects energy, and the earthquake radiation pattern. reported. Each earthquake is further Magnitude values calculated by USGS are based on characterized by its maximum intensity, which is the following formulae: given in the text and in table 1. Although the Modified Mercalli Intensity Scale is in many instances inadequate for MS = log (A/T) + 1.66 log D + 3.3, (1) present-day requirements, the scale has been the National Oceenk and Atmospheric Administration Environmental Data Service 1976 Figure 2.--Earthquakes plotted by Modified Mercalli Intensity in 1976 guide used by NOAA and USGS and will continue to Trees, bushes, shaken slightly. be so used until a new scale has been devised and has acceptance in the engineering and VI. Felt by all, indoors and outdoors. seismological communities. Questions concerning Frightened many, excitement general, some alarm, the interpretation of historical earthquake many ran outdoors. Awakened all. Persons made to intensities should be referred to USGS. move unsteadily. Trees, bushes, shaken slightly to moderately. Liquid set in strong motion. Small bells rang--church, chapel, school, etc. Damage slight in poorly built buildings. Fall of MODIFIED MERCALLI INTENSITY SCALE plaster in small amount. Cracked plaster somewhat, especially fine cracks in chimneys in I. Not felt - or, except rarely under some instances. Broke dishes, glassware, in especially favorable circumstances. Under certain considerable quantity, also some windows. conditions, at and outside the boundary of the Fall of knickknacks, books, pictures. area in which a great shock is felt: Overturned furniture in many instances. Moved sometimes birds, animals, reported uneasy or furnishings of moderately heavy kind. disturbed; sometimes dizziness or nausea experienced; sometimes trees, structures, liquids, VII. Frightened all--general alarm, all ran bodies of water, may sway--doors may swing, very outdoors. Some, or many, found it difficult slowly. to stand. Noticed by persons driving motor cars. Trees and bushes shaken moderately to II. Felt indoors by few, especially on strongly. Waves on ponds, lakes, and running upper floors, or by sensitive, or nervous persons. water. Water turbid from mud stirred up. Also, as in grade I, but often more noticeably: Incaving to some extent of sand or gravel stream sometimes hanging objects may swing, especially banks. Rang large church bells, etc. Suspended when delicately suspended; sometimes trees, objects made to quiver. Damage negligible in structures, liquids, bodies' of water, may sway, buildings of good design and construction, doors may swing, very slowly; sometimes birds, slight to moderate in well-built ordinary animals, reported uneasy or disturbed; sometimes buildings, considerable in poorly built or badly dizziness or nausea experienced. designed buildings, adobe houses, old walls (especially where laid up without mortar), III. Felt indoors by several, motion usually spires, etc. Cracked chimneys to considerable rapid vibration. Sometimes not recognized to be extent, walls to some extent. Fall of plaster in an earthquake at first. Duration estimated in considerable to large amount, also some stucco. some cases. Vibration like that due to passing Broke numerous windows, furniture to some of light, or lightly loaded trucks, or heavy extent. Shook down loosened brickwork and tiles. trucks some distance away. Hanging objects may Broke weak chimneys at the roofline (sometimes swing slightly. Movements may be appreciable on damaging roofs). Fall of cornices from towers upper levels of tall structures. Rocked standing and high buildings. Dislodged bricks and stones. motor cars slightly. Overturned heavy furniture, with damage from breaking. Damage considerable to concrete IV. Felt indoors by many, outdoors by few. irrigation ditches. Awakened few, especially light sleepers. Frightened no one, unless apprehensive from VIII. Fright general--alarm approaches panic. previous experience. Vibration like that due to Disturbed persons driving motor cars. Trees passing of heavy, or heavily loaded trucks. shaken strongly--branches, trunks, broken off, Sensation like heavy body striking building, or especially palm trees. Ejected sand and mud in falling of heavy objects inside. Rattling of small amounts. Changes: temporary, permanent; in dishes, windows, doors; glassware and crockery flow of springs and wells; dry wells renewed clink and clash. Creaking of walls, frame, flow; in temperature of spring and well especially in the upper range of this grade. waters. Damage slight in structures (brick) built Hanging objects swung, in numerous instances. especially to withstand earthquakes. Disturbed liquids in open vessels slightly. Considerable in ordinary substantial buildings, Rocked standing motor cars noticeably. partial collapse: racked, tumbled down, wooden houses in some cases; threw out panel walls in V. Felt indoors by practically all, outdoors frame structures, broke off decayed piling. by many or most: outdoors direction estimated. Fall of walls. Cracked, broke, solid stone Awakened many, or most. Frightened walls seriously. Wet ground to some extent, also few--slight excitement, a few ran outdoors. ground on steep slopes. Twisting, fall, of Buildings trembled throughout. Broke dishes, chimneys, columns, monuments, also factory glassware, to some extent. Cracked windows--!'n stacks, towers. Moved conspicuously, overturned, some cases, but not generally. Overturned vases, very heavy furniture. small or unstable objects, in many instances, witn occasional fall. Hanging objects, doors, I.. Panic general. Cracked ground swing generally or considerably. Knocked pictures conspicuously. Damage considerable in (masonry) against walls, or swung them out of place. structures built especially to withstand Opened, or closed, doors, shutters, abruptly. earthquakes: threw out of plumb some wood-frame Pendulum clocks stopped, started, or ran fast, or houses built especially to withstand slow. Moved small objects, furnishings, the earthquakes; great in substantial (masonry) latter to slight extent. Spilled liquids in buildings, some collapse in large part; or wholly small amounts from well-filled open containers. shifted frame buildings off foundations, racked frames; serious to reservoirs; underground pipes California (at large). Nina Scott, San sometimes broken. Francisco. California (northern). Bruce A. Bolt, X. Cracked ground, especially when loose and University of California, Berkeley. wet, up to widths of several inches; fissures up California (southern).--Clarence R. Alien, to a yard in width ran parallel to canal and California Institute of Technology, Pasadena. stream banks. Landslides considerable from Colorado.--Maurice W. Major, Colorado School river banks and steep coasts. Shifted sand and of Mines, Golden. mud horizontally on beaches and flat land. Connecticut. Edward F. Chiburis, University Changed level of water in wells. Threw water on of Connecticut, Groton. banks of canals, lakes, rivers, etc. Damage Del aware.--Robert R. Jordan, University of serious to dams, dikes, embankments. Severe to Delaware, Newark. well-built wooden structures and bridges, some Florida and Georgia.--Leiand T. Long, Georgia destroyed. Developed dangerous cracks in Institute of Technology, Atlanta. excellent brick walls. Destroyed most masonry Hawaii.--Robert Koyanagi, USGS, Hawaiian and frame structures, also their foundations. Volcano Observatory, Hawaii National Park. Bent railroad rails slightly. Tore apart, or Idaho. Melvin W. Jackson, Morrison-Knudsen crushed endwise, pipelines buried in earth. Open Co., Inc., Industrial Engineering Group, Boise. cracks and broad wavy folds in cement pavements Indiana.--Robert F. Blakely, Department and asphalt road surfaces. of Natural Resources, Geological Survey, Bloomington. XI. Disturbances in ground many and widespread, Iowa. J.P. Kopp, Loras College, Dubuque. varying with ground material. Broad fissures, Kansas.--Robert J. Harris, Kansas State earth slumps, and land slips in soft, wet University, Manhattan. ground. Ejected water in large amounts Kentucky.--G. Randy Keller, University of charged with sand and mud. Caused sea-waves Kentucky, Lexington. ("tidal" waves) of significant magnitude. Damage Michigan. James T. Wilson, University of severe to wood-frame structures, especially near Michigan, Ann Arbor. shock centers. Great to dams, dikes, Minnesota.--Harold Mooney, University of embankments, often for long distances. Few, if Minnesota, Minneapolis. any (masonry), structures remained standing. Mississippi, Louisiana area. Fred Followill, Destroyed large well-built bridges by the University of Mississippi, University. wrecking of supporting piers, or pillars. Missouri, Illinois, Arkansas area.--William Affected yielding wooden bridges less. Bent J. Stauder and Otto Nuttli, Saint Louis railroad rails greatly, and thrust them endwise. University, Saint Louis. Put pipelines buried in earth completely out of Montana. Stephen W. Nile, Gallatin Gateway. service. Nevada. Douglas Van Wormer, University of Nevada, Reno. XII. Damage total--practically all works of New England. Francis J. Donohoe, S.J., construction damaged greatly or destroyed. Daniel J. Linehan, S.J., and James W. Skehan, Disturbances in ground great and varied, S.J., Weston College, Weston, Mass. numerous shearing cracks. Landslides, falls of New Mexico. Allan R. Sanford, New Mexico rock of significant character, slumping of river Institute of Mining and Technology, Socorro. banks, etc., numerous and extensive. Wrenched New York. Lynn R. Sykes, Lamont-Doherty loose, tore off, large rock masses. Fault Geological Observatory, Palisades. slips in firm rock, with notable horizontal and North Carolina. David M. Stewart, University vertical offset displacements. Water channels, of North Carolina, Chapel Hill. surface and underground, disturbed and modi fed Ohio. Edward J. Walter, John Carrol 1 greatly. Dammed lakes, produced waterfalls, University, Cleveland. deflected rivers, etc. Waves seen on ground Oklahoma.--James E. Lawson, Jr., University surfaces (actually seen, probably, in some cases). of Oklahoma, Leonard. Distorted lines of sight and level. Threw Oregon.--Richard W. Couch, Oregon State objects upward into the air. University, Corvallis. Pennsylvania.--Benjamin F. Howell, Jr., Pennsylvania State University, University Park. South Carolina. Pradeep Talwani, University Acknowledgments of South Carolina, Columbia. Tennessee. Berien C. Moneymaker, Knoxville. Texas.--James Dorman, University of Texas, Active cooperation in earthquake investiga­ Galveston. tions in the United States is provided by several Utah. Kenneth Cook, University of Utah, Salt seismology collaborators. The following served as Lake City. collaborators to NOAA and USGS during 1976. Virginia.--G.A. Bollinger, Virginia Polytechnic Institute and State University, Alabama.--L.J. Eisele, Spring Hill College, Blacksburg. Mobile. Washington. Norman Rasmussen and Robert Alaska. Staff of NOAA-Palmer Observatory, S. Crosson, University of Washington, Seattle. Palmer, and J.B. Townshend, College West Virginia.--R.W. Laird, University of Observatory, College. West Virginia, Morgantown. Arizona.--Richard T. Moore, University of Wisconsin. David E. Willis, University of Arizona, Tucson. Wisconsin, Milwaukee. Earthquake Descriptions

This section lists all earthquakes alphabetically by state. The origin time of Alaska earthquake occurrences is given in Universal Coordinated Time (UTC), which is expressed continuously from midnight to midnight, or 0 to 24 7 January (G) Southern Alaska hours. The following symbols are used to indicate Origin time: 17 18 46.7 authority for arrival or origin times, epicenters, Epicenter: 61.86 N., 150.67 W. magnitudes, and (or) intensity data. Depth: 44 km Magnitude: None computed. A University of West Virginia, Morgantown. Intensity III: Palmer (press report). B University of California at Berkeley. C University of Connecticut, Groton. D University of Montana, Missoula. 13 January (G) Andreanof Islands, Aleutian Islands E California Dept. of Water Resources, Origin time: 23 48 22.6 Sacramento. Epicenter: 51.79 N., 174.70 W. F--USGS Open-File Report 77-181 (Fuis and Depth: 33 km others, 1977). Magnitude: 3.9 mb G U.S. Geological Survey (USGS), National Intensity II: Adak. Earthquake Information Service, Golden, Colo. 15 January (G) Southern Alaska H U.S. Geological Survey, Hawaiian Volcano Origin time: 02 17 20.4 Observatory, Hawaii National Park. Epicenter: 61.74 N., 149.77 W. I Dept. of Natural Resources, Bloomington, Depth: 30 km Ind. Magnitude: None computed. J Weston Observatory, Weston, Mass. Intensity II: Willow. K--NOAA, Adak Observatory, Alaska. L Lamont-Doherty Geological Observatory, Palisades, N.Y. 15 January (G) Central Alaska M NOAA, Alaska Tsunami Warning Center, Origin time: 13 12 31.2 Palmer. Epicenter: 62.26 N., 150.46 W. N Georgia Institute of Technology, Atlanta. Depth: 33 km 0 Seismological Service of Canada, Ottawa. Magnitude: 3.3 ML(M) P California Institute of Technology, Intensity IV: Talkeetna. Pasadena. R University of Nevada, Reno. 17 January (G) Southern Alaska S St. Louis University, St. Louis, Mo. Origin time: 09 09 51.4 T University of Oklahoma, Leonard. Epicenter: 61.44 N., 148.38 W. U University of Utah, Salt Lake City. Depth: 28 km V Virginia Polytechnic Institute and State Magnitude: 2.6 ML(M) University, Blacksburg. Intensity II Palmer (M). W University of Washington, Seattle. Y University of Kentucky, Lexington. 22 January (G) Southern Alaska Z Oregon State University Tech. Report Origin time: 07 59 20.0 GTR 760915 (Couch and Farooqui, 1976). Epicenter: 61.57 N., 149.96 W. Depth: 59 km Sources of noninstrumental information Magnitude: None computed. (macroseismic data) in this publication include Intensity II: Nancy Lake (M). questionnaire canvasses conducted by USGS; newspaper articles; bulletins of the Seismological 23 January (G) Fox Islands, Aleutian Islands Society of America; special earthquake reports Origin time: 13 03 04.7 of other organizations; and information collected Epicenter: 53.52 N., 166.49 W. by NOAA's National Weather Service. Instrumental Depth: 104 km data are provided by the USGS, National Earthquake Magnitude: 3.7 mb Information Service. Intensity IV: Unalaska, Dutch Harbor (M), Roman numerals in the earthquake descriptions 5 February (G) Kenai Peninsula, Alaska refer to the Modified Mercalli Intensity Scale of Origin time: 09 36 36.5 1931 (see page 5), which gives about equal weight Epicenter: 59.99 N., 149.35 W. to the disturbance of inanimate objects and to Depth: 35 km personal reactions. When more than one degree of Magnitude: 5.2 mb, 3.9 MS, 4.8 ML(M) intensity is reported from a town, the town is Intensity V: Seward (M). assigned the highest intensity reported. All Intensity IV: Moose Pass area (M). earthquake reports that contain minimal Intensity III: Anchorage, Whittier (M). information are assigned intensity II. Intensity II: Palmer (M). Alaska Continued Alaska Continued

18 February (G) Andreanof Islands, Aleutian Intensity III: Sitkinak Island (Trinity Islands Island group), Old Harbor area. Origin time: 08 00 58.6 Epicenter: 51.57 N., 178.68 W. 26 March (G) Central Alaska Depth: 39 km Origin time: 14 40 14.2 Magnitude: 4.9 mb, 4.3 MS Epicenter: 63.60 N., 147.65 W. Intensity IV: Adak (K). Depth: 33 km Magnitude: 4.1 mb, 4.2 ML(M) 19 February (G) Andreanof Islands, Aleutian Intensity IV Fairbanks. Islands Origin time: 10 28 33.5 11 April Central Alaska Epicenter: 52.50 N., 179.52 W. Origin time: 07 36 Depth: 212 km Epicenter: Not located. Magnitude: 4.9 mb Depth: None computed. Intensity II: Adak (K). Magnitude: None computed. Intensity IV; College. 22 February (G) Andreanof Islands, Aleutian 14 April (G) Central Alaska Islands Origin time: 04 16 16.3 Origin time: 07 21 25.8 Epicenter: 62.15 N., 150.26 W. Epicenter: 51.73 N., 176.87 W. Depth: 33 km Depth: 58 km Magnitude: 3.1 ML(M) Magnitude: 5.0 mb Intensity IV; Talkeetna. Intensity IV; Adak (K). 17 April (G) Central Alaska 28 February (G) Andreanof Islands, Aleutian Origin time: 06 08 44.5 Islands Epicenter: 64.90 N., 148.31 W. Origin time: 09 43 58.0 Depth: 33 km Epicenter: 51.56 N., 178.54 W. Magnitude: 4.0 Ml(M) Depth: 32 km Intensity V Fairbanks. Magnitude: 4.8 mb Intensity II; North Pole. Intensity II: Adak (K). 25 April (G) Central Alaska 8 March (G) Andreanof Islands, Aleutian Islands Origin time: 10 12 09.4 Origin time: 02 28 47.7 Epicenter: 64.79 N., 147.67 W, Epicenter: 51.34 N., 178.04 W. Depth: 34 km Depth: 54 km Magnitude: 3.3 ML(M) Magnitude: 4.7 mb, 4.1 MS Intensity V; Fairbanks. Intensity III; Adak (K). 27 April (G) Central Alaska 13 March (G) Central Alaska Origin time: 11 26 57.5 Origin time: 14 33 42.5 Epicenter: 64.81 N., 147.49 W. Epicenter: 63.50 N., 148.67 W. Depth: 33 km Depth: 22 km Magnitude: 3.8 MUM) Magnitude: 3.9 mb, 4.2 ML(M) Intensity IV: Fairbanks. Intensity V: Cantwell, Summit area, Intensity III; Broad Pass, Suntrana. 27 April (G) Central Alaska Origin time: 11 34 20.0 13 March (G) Central Alaska Epicenter: 64.73 N., 147.58 W. Origin time: 15 18 57.8 Depth: 29 km Epicenter: 63.51 N., 148.70 W. Magnitude: 3.0 ML(M) Depth: 45 km Intensity V: Fairbanks (aftershock felt Magnitude: 3.3 MUM) 5 minutes later). Intensity III: Cantwell. 8 May (G) Southern Alaska 21 March (G) Kenai Peninsula Origin time: 11 25 36.3 Origin time: 17 20 27.9 Epicenter: 61.62 N., 151.52 W, Epicenter: 60.87 N., 149.69 W. Depth: 16 km Depth: 59 km Magnitude: 4.4 mb, 4.4 ML(M) Magnitude: None computed. Intensity IV: Kenai. Intensity III: Alyeska, Anchorage, Palmer Intensity II: Talkeetna. (M). 9 May (G) Southern Alaska 25 March (G) Kodiak Island region Origin time: 00 09 50.7 Origin time: 07 49 33.6 Epicenter: 59.86 N., 153.07 W. Epicenter: 57.01 N., 153.71 W. Depth: 38 km Depth: 28 km Magnitude: 4.7 mb, 3.9 ML(M) Magnitude: 5.0 mb Intensity IV Homer, Iliamna. Alaska--Continued Alaska Continued

11 May (G) Southern Alaska Magnitude: 4.9 mb Origin time: 16 46 15.8 Intensity II; Adak. Epicenter: 61.49 N., 146.97 U, Depth: 67 km 30 July (G) Southern Alaska Magnitude: 4.2 mb Origin time: 13 54 32.2 Intensity III Valdez. Epicenter: 61.33 N., 147.45 W. Depth: 40 km 26 May (G) Kodiak Island Region Magnitude: 3.9 mb, 4.0 ML(M) Origin time: 17 38 22.2 Intensity II Valdez. Epicenter: 57.97 N., 153.30 W. Depth: 33 km 11 August (G) Andreanof Islands, Aleutian Islands Magnitude: 4.5 mb Origin time: 20 43 45.5 Intensity III: Kodiak Island. Epicenter: 51.70 N., 175.42 W. Depth: 33 km 1 June (G) Central Alaska Magnitude: 4.6 mb Origin time: 16 30 55.5 Intensity III: Adak. Epicenter: 64.70 N., 147-80 W. Depth: 9 km 16 August (G) Andreanof Islands, Aleutian Islands Magnitude: 2.9 MUM) Origin time: 05 11 38.9 Intensity II: Epicentral region. Epicenter: 51.50 N., 178.38 W. Depth: 65 km 10 June (G) Andreanof Islands, Aleutian Islands Magnitude: 5.1 mb Origin time: 08 57 59.6 Intensity II: Adak. Epicenter: 51.52 N., 176.54 W. Depth: 58 km 16 August (G) Andreanof Islands, Aleutian Islands Magnitude: 4.5 mb Origin time: 10 11 33.3 Intensity II: Adak. Epicenter: 51.49 N., 178.05 W. Depth: 55 km 14 June (G) Andreanof Islands, Aleutian Islands Magnitude: 4.8 mb, 3.9 MS Origin time: 12 39 39.0 Intensity II: Adak. Epicenter: 51.47 N., 176.85 W. Depth: 50 km 22 August (G) Southern Alaska Magnitude: 4.1 mb Origin time: 02 01 47.4 Intensity III: Adak. Epicenter: 60.22 N., 153.30 W. Depth: 144 km 24 June (G) Central Alaska Magnitude: 5.5 mb Origin time: 13 36 59.2 Epicenter: 61.97 N. 150.90 W. An observer near the epicenter noted: Depth: 73 km Campers at the west end of Kontrashibuna Magnitude: 4.8 mb Lake, at about 60.15 N., 153.90 W., heard a Intensity III: Talkeetna. loud noise to the southeast, looked immediately in that direction, but saw 5 July (G) Andreanof Islands, Aleutian Islands nothing. Experienced mountaineers in the Origin time: 18 25 17.7 group agreed later that it sounded like a Epicenter: 51.30 N., 179.14 W. rock avalanche, and that if it had been a Depth: 61 km rockfall they would have seen it. Less Magnitude: 4.6 mb than a minute later they saw a 5-8 cm swell Intensity II Adak. on the lake reach the shore where they were camped, even though it was a windless day. 5 July (G) Andreanof Islands, Aleutian Islands Waves 5 to 8 cm in height continued to Origin time: 18 28 28.0 break on the shore from many directions for Epicenter: 51.33 N., 179.16 W. several minutes before beginning to Depth: 54 km subside. The water was murky for at least Magnitude: 5.2 mb one-half hour afterward. None of the Intensity II: Adak. campers felt any indication of earth movement. 15 July (G) Central Alaska Origin time: 08 09 47.4 Intensity VI; Kenai (small ground Epicenter: 62.70 N., 149.83 W. cracks unconfirmed), Ninilchik (small Depth: 24 km objects fell, not broken). Magnitude: 4.2 mb, 4.6 ML(M) Intensity V: Anchorage (small objects Intensity IV Talkeetna. moved, many people frightened), Anchor Point (water sloshed), Clam Gulch, Homer 22 July (G) Andreanof Islands, Aleutian Islands (water sloshed), Kasilof (surface of water Origin time: 14 30 17.7 disturbed, small objects moved), Nondalton Epicenter: -51.49 N., 177.86 W. (observer drifting in small boat on Depth: 58 km Snowshoe Bay felt vibration), Port Graham Alaska Continued Alaska Continued

(small objects moved), Port Lions, Seward 24 October (G) Central Alaska (small objects moved), Soldotna, Sterling Origin time: 17 19 53.7 (observer picking berries felt shaking Epicenter: 62.65 N., 149.14 W. "longer than 2 minutes", water sloshed), Depth: 75 km Wasilla (small objects moved). Magnitude: 4.9 mb Intensity IV: Aniak, Chugiak, Nyac, Old Intensity III: South-central Alaska (press Harbor, Ouzinkie, Seldovia, Talkeetna. report). Intensity III: Mill Bay, Kodiak, Palmer. 11 November (G) Southern Alaska 25 August (G) Kenai Peninsula Origin time: 18 18 30.5 Origin time: 11 04 18.9 Epicenter: 61.31 N., 149.79 W. Epicenter: 60.61 N., 150.17 W. Depth: 33 km Depth: 47 km Magnitude: 3.2 ML(M) Magnitude: None computed. Intensity II: Reported felt; a specific town Intensity III: Anchorage, northern Kenai was not given. Peninsula. 30 November (G) Southern Alaska 28 August (G) Andreanof Islands, Aleutian Islands Origin time: 06 22 35.3 Origin time: 02 30 09.2 Epicenter: 59.92 N., 153.36 W. Epicenter: 52.60 N., 175.34 W. Depth: 127 km Depth: 145 km Magnitude: 4.7 mb Magnitude: 5.1 mb Intensity IV: Kenai-Anchor Point area. Intensity III: Adak. Intensity III: Anchorage, Homer. 5 September (G) Andreanof Islands, Aleutian Islands 15 December (G) Southern Alaska Origin time: 10 33 49.0 Origin time: 09 51 32.3 Epicenter: 51.40 N., 178.77 W. Epicenter: 61.35 N., 150.25 W. Depth: 68 km Depth: 51 km Magnitude: 4.4 mb Magnitude: 3.7 mb Intensity II: Adak. Intensity III: Anchorage, Peters Creek, 15 September (G) Southern Alaska 15 December (G) Central Alaska Origin time: 16 44 29.6 Origin time: 13 35 53.8 Epicenter: 61.08 N., 150.62 W. Epicenter: 64.83 N., 147.87 W. Depth: 74 km Depth: 31 km Magnitude: None computed. Magnitude: 3.0 ML(M) Intensity II: Anchorage. Intensity IV: Fairbanks. 21 September (G) Kodiak Island region Origin time: 03 01 04.6 Epicenter: 57.84 N., 152.12 W. Arizona Depth: 33 km Magnitude: 4.9 mb, 4.6 ML(M) Intensity III: Kodiak. 4 February (G) Western Arizona Origin time: 00 04 58.1 22 September (G) Andreanof Islands, Aleutian Epicenter: 34.66 N., 112.50 W. Islands Depth: 12 km Origin time: 02 30 25.7 Magnitude: 4.9 mb, 5.1 ML, 5.2 ML(P) Epicenter: 51.72 N., 175.95 W. Depth: 43 km USGS personnel conducted a field survey fol­ Magnitude: 4.8 mb, 5.1 MS lowing this earthquake. USGS also can­ Intensity IV: Adak. vassed an area around the epicenter and mailed 362 questionnaires. 27 September (G) Southern Alaska Origin time: 05 59 45.7 Epicenter: 60.46 N., 145.17 W. The earthquake was felt over an area of about Depth: 41 km 25,000 sq km, from Yuma to Tucson and as Magnitude: 4.0 mb, 3.3 ML(M) far north as Flagstaff (see fig. 3). It Intensity III: Cordova. apparently was strongest in the vicinity of Prescott. Minor damage occurred in Chino 18 October (G) Central Alaska Valley, Cottonwood, Miller Valley (suburb Origin time: 00 36 31.6 of Prescott), and Paul den. Many fallen Epicenter: 63.29 N., 150.74 W. rocks and boulders were observed south of Depth: 126 km Prescott on Highway 89, a winding, moun­ Magnitude: 4.9 mb tainous road in Prescott National Forest. Intensity IV: Cantwell, Colorado. These are believed to have resulted from an Intensity II: Anchorage, Palmer. intense rainstorm on February 4-5, not from 10 Arizona Continued Arizona Continued

the earthquake. Telephone service was in­ be difficult to ascertain that any damage terrupted for a short time, such that calls was due to the shock. He reportedly saw could be made but not received. After­ waves on the ground and nearly fell over. shocks awakened many at 10 p.m., February 3 He also told the USGS team he had lived in and at 2 a.m. and 6 a.m., February 4 (local California for 30 years before coming to time). Arizona. Between February 4 and February 9, 12 after­ The Forest Ranger said there was a report shocks were reported by the Arizona State of muddied water in a well in the area. University Seismograph Station. This was unconfirmed. Cottonwood--Slight damage. Trees and Most of the housing in the sparsely settled bushes shook. epicentral area that was surveyed by USGS Miller Valley In this northern suburb of consisted of mobile-trailer homes, some of Prescott, the recently constructed (1975) which were placed on concrete platforms addition to the Safeway supermarket had and called "modular homes." Many were on small cracks in the west wall, beginning at cinderblocks and "skirted" with sheet- the ceiling and extending downward about 1 metal or some other material. There were m where they disappeared behind shelves. few brick chimneys in the area. These cracks were located at the juncture Intensity VI: of the old and new sections of the store. Chino Valley At the Buckaroo shopping The mortar joining the cinderblocks was center and liquor store, bottles were cracked in a way that might have indicated thrown from shelves along the north wall. settling. The assistant manager was sure Estimated loss from breakage was about the cracks were not present before the $100. Bottles along the shelves on the earthquake. The liquor department just west wall rattled but did not fall. adjacent to the cracked wall is in the new This one-story building of recent frame section along the west wall. The bottles construction on flat ground had ceiling rattled and clinked together, but none was beams from east to west. One beam was thrown from the shelf. loosened slightly and the plaster separated Paulden--Trees and bushes shook in this from the ceiling. The beams were not small community, about 12 km north of Chino structural members of the building, but Valley. The barmaid at the only bar in ornamental. town said she heard of a mirror falling The proprietor of the Shell gas station in from the wall at one residence. A lamp this town said cracks in the cinderblock hanging in the bar swung considerably partition in his garage probably were due during the earthquake. to the earthquake. The building was in The retired deputy-sheriff reported that such poor condition, however, that it would the most significant thing he noticed was the sound of a large explosion coming from

115° 109°

. * Epicenter 5 Felt at intensity o Not felt

Figure 3. Area affected by western Arizona earthquake of February 4 11 Arizona Continued Arizona Continued

a northeasterly direction, at or' near 7 December (P) Baja California Dillard's Verde River Ranch. Origin time: 12 59 56.3 One resident reported that the waste-line Epicenter: 31.98 N., 114.78 W. to his son's trailer-home had been broken Depth: 8 km off by the earthquake. He also stated that Magnitude: 5.5 mb(G), 5.7 MS(G), 5.2 ML it had been loose for some time and that Intensity VI; when the shock occurred, the waste-line Arizona--San Luis (furniture moved; damage became disconnected. slight), Wellton (broken windows--press Intensity V; Cornville, Dewey, Jerome, report), Yuma (broken windows telephone Mayer, Peeples Valley (field report), Rio report; broken waterline at Del Oro Verde Ranch (southeast of Paul den), Skull Mobile Estates press report). Valley. Interviews in Skull Valley and California El Centro (plaster cracked; Peeples Valley, and in small wayside stops, furniture moved). gas stations, and cafes revealed that Intensity V: almost everybody felt the main shock and Arizona--Gadsden, Martinez Lake, Roll, the aftershocks. Most of those who noticed Somerton. the swing of hanging objects stated that California Bard (small objects moved), the direction was from north to south. The Borrego Springs, Boulevard, Campo, places mentioned here are all south and Jacumba, Mount Laguna, Ocotillo, west of Prescott. Winterhaven. Intensity IV: Intensity IV: Arizona Ash Fork, Humboldt, Phoenix, California Brawley, Glamis, Julian, La Piacho, Rimrock, Wickenburg, Wide Mesa, Santa Ysabel. Ruin, Yarnell. Intensity I'll: California Parker Dam. Cali forni a San Diego (press report). Intensity III; Bouse, Wikieup. IntensityTlT Chloride, Seligman. Arkansas

9 February (G) Western Arizona Origin time: 03 07 22.0 16 January (G) Northern Arkansas Epicenter: 34.61 N., 112.53 W. Origin time: 19 42 57.0 Depth: 10 km Epicenter: 35.92 N., 92.12 W. Magnitude: 4.6 mb, 3.3 ML Depth: 14 km Intensity II Chino Valley area. Magnitude: 3.2 ML(S) Intensity V: Blanchard Springs Cavern (felt 23 February (G) Western Arizona by all in cave; underground rocks fell), Origin time: 14 09 54.4 Onia (felt strongly 7 km north of; trees Epicenter: 34.68 N., 112.43 W. and bushes were noticeably disturbed). Depth: 10 km Intensity IV: Bull Shoals, Cotter, Magnitude: 3.5 ML Fifty-six, Mountain View, Norfolk. Intensity VI Chino Valley (plaster Intensity III: Mountain Home (telephone cracked). report). Intensity V: Humboldt, Prescott, Skull Intensity II: (Press reports) Calico Rock, Valley. Salesville, Sycamore Springs. Intensity IV Dewey, Paul den. 25 March (S) Northeastern Arkansas Origin time: 00 41 20.5 Epicenter: 35.59 N., 90.48 W. 19 April (G) Northeastern Arizona Depth: 15 km Origin time: 23 35 45.5 Magnitude: 4.9 mb(G), 5.0 ML Epicenter: 35.39 N., 109.10 W. Depth: 5 km USGS canvassed an area around the epicenter Magnitude: 3.5 ML within a radius of 500 km and mailed 1,809 questionnaires. Figure 4 shows the results This might have been an explosion in the Four of this canvass. The quake was felt over Corners area. an area of approximately 280,000 sq km, including Alabama, Arkansas, Illinois, Intensity V: St. Michaels. Indiana, Kentucky, Mississippi, Missouri, Intensity IV: Window Rock. and Tennessee. Slight damage occurred in several towns in Arkansas, Mississippi, 4 May (G) Western Arizona Missouri, and Tennessee. This earthquake Origin time: 10 06 34.8 triggered seven accelerographs located at Epicenter: 34.70 N., 112.54 W. four stations Arkabutla Dam, Miss.; Depth: 10 km Wappapelo Dam, Mo.; Tiptonville, Tenn.; and Magnitude: 3.0 ML New Madrid, Mo. The maximum recorded Intensity II; Prescott. acceleration was 0.04 g (R.L. Porcella, 12 Arkansas Ccntinued Arkansas Continued

Figure 4.--Area affected by northeastern Arkansas earthquake of March 25

personal commun., 1977). An aftershock was Missouri Arab, Arbyrd, Brandsville, Hunter felt in several towns at about 01:00 UTC. (cracked house foundation; crack enlarged in concrete steps), Lilbourn (plaster Intensity VI: cracked), Puxico. Arkansas Bay (furniture moved, small Tennessee Brunswick (plaster cracked), objects broke), Biggers, Blytheville, Drummonds, Dyersburg, Ellendale, Macon Brookland, Bunker (plaster and dry wall (plaster cracked), Memphis (minor damage cracked), Cash, Datto, Decatur at nine Memphis Fire Department stations; (unconfirmed reports of minor property books shaken from shelves in 11-story damage; ceiling tiles fell and some roof library tower at Memphis State damage press report), Delaplaine, Dolph, University press report), Tipton Egypt, Hardy, Harrisburg (plaster (plaster cracked slightly), Union City cracked), Jonesboro (power blackout, (damage to telephone circuits press telephone lines down; ceilings, walls and report). floors shook violently at state police Intensity V: headquarters, which is 7.6 m Alabama Albertville, Bankston, Cherokee, underground press report), Knobel Coker, Florence (furniture moved press (plaster cracked), Lake City, Lepanto report), Lawrence County (some downed (dry wall cracked), Luxora, Marked Tree powerlines press report), Lexington, (plaster cracked), McDougal, Minturn, Muscle Shoals (press report), Waterloo. Okean, Paragould (windows broken; $700 Arkansas Alexander, Augusta, Balch, damage estimated press report), Peach Bassett, Batesville (powerlines Orchard (dry wall cracked), Portia, down press report), Beech Grove, Bexar, Sedgwick, Smithville, Tomato, Trumann Biscoe, Black Oak, Black Rock, Boswell, (dry wall cracked; ceiling tiles fell), Brickeys, Brinkley, Burdette, Caldwell, Twist, Walnut Ridge (windows blown out in Camp, Cave City, Chatfield, Cherry downtown businesses press report). Valley, Clarendon, Concord, Cord, Kentucky Fancy Farm. Corning, Cotter, Coy, Crawfordsville, Mississippi Abbevilie, Arkabulta, Falkner Cushman, Dardanelle, Dell, Devalls Bluff, (plaster cracked), Michigan City, Tupelo Diaz, Dyess, Earle, Edmondson, Ethel, (knocked down ceiling panels in one home; Etowah, Fisher, Forrest City, Franklin, cracked masonry press report). Gepp, Gillett, Gilmore, Glencoe, Goodwin, 13 Arkansas--Conti nued Arkansas Conti nued

Greenway, Gregory, Griffithville, Grubbs. Teresita, Thayer, Vanduser, Wardell, Helena, Henderson, Heth, Higden, Washington, West Plains (press report), Higginson, Howell, Hoxie, Hughes, Winona, Zalma. Humphrey, Hunter, Imboden, Jacksonport, Tennessee Alamo, Atwood, Beech Bluff, Jefferson, Joiner, Jordan, Keiser, Bells, Bolivar, Braden, Brighton, Kensett, Keo, La Grange, Leachville, Brownsville, Burlison, Cedar Grove, Light, Locust Grove, Lynn, Mammoth Clifton, College Grove, Collierville, Spring, Manila, Marcella, Marianna, Covington, Crockett Mills, Denmark, Marmaduke, Marvell, Maynard, Mcrae, Denver, Dukedom, Dyer, Elora, Finley, Mellwood, Moro, Moscow, Mount Pleasant, Fort Pillow, Friendship, Fruitland, Mountain Home, Mountain View, Newark, Fruitvale, Gadsden, Gall away, Gattes, Newport, Nimmons, Norfork, Oil Trough, Grand Junction, Greenfield, Guys, Halls, Osceola, Oxford, Palestine, Pineville, Henderson, Hickory Valley, Hickory Withe, Pleasant Grove, Pocahontas, Powhatan, Hornbeak, Hornsby, Idlewild, Jackson, La Proctor, Ravenden, Ravenden Springs, Grange, Laconia, Lavinia, Leach, Reydell, Reyno, Roe, Rosie, Round Pond, Lexington, Lyles, Luray, Maury City, Saffell, Saint Charles, Saint Francis, Medina, Milledgeville, Millington, Shoffner, Smithville, Stonewall, Munford, Newbern, North Memphis (press Strawberry, Sweet Home, Swifton, Tilly, report), Oakfield, Obion, Pinson, Ramer, Tucker, Tuckerman, Turner, Tyronza, Ridgely, Ripley, Rives, Rutherford, Vanndale, Violet Hill, Wabbaseka, Samburg, Saulsbury, Selmer, Silerton, Walcott, Waldenburg, Weiner, Weldon, West Somerville, Trenton, Trimble, Troy, Helena, West Memphis, West Ridge, Williston, Yorkville. Wheatley, Wideman, Widener, Williford, Intensity IV: Wilson. Alabama Adger, Brent, Burnwell, Illinois--Cisne, Edwardsville. Cloverdale, Echola, Ethelsville, Ford Kentucky--Canton, Clinton, Farmington, City (press report), Gainesville, Fulton, Grand Rivers, Lovelaceville, Hamilton (press report), Killen, New Wingo. Market, Northport (press report), Mississippi--Alligator, Ashland, Askew, Ragland, Samantha, Sheffield (press Batesville (powerlines down press report), Tanner, Tuscaloosa (severe report), Belen, Blue Mountain, Blue shaking on top floors of hospital press Springs, Carthage, Cleveland, Coahoma, report), Woodlawn (lamps shook, glasses Coffeeville, Coldwater, Como, Crenshaw, rattled press report). Darling, Derma, Duck Hill, Dumas, Duncan, Arkansas Beebe, Birdeye, Blackwell, Dundee, Ecru, Elliott, Etta, Friars Bradford, Byron, Calico Rock, Choctaw, Point, Glendora, Gore Springs, Hernando Clinton, Cotton Plant, Crocketts Bluff, (powerlines down press report), Hickory Crumrod, Damascus, Dennard, Drasco, Flat, Holly Springs (all residents Edgemont, Elaine, Elizabeth, England, alarmed press report), Lake Cormorant, Fargo, Floral, Forty Four, Gamaliel, Lamar, Le Flore, Marks, Mattson, Mineral Gilbert, Gould, Grand Glaise, Guion, Wells, Minter City, Moorhead, Nesbit, Hamilton, Haynes, Hazen, Heber Springs, Olive Branch, Oxford, Pittsboro, Pleasant Holly Grove, Humnoke, Jacksonville, Grove, Potts Camp, Red Banks, Rienzi, Lacrosse, Leslie, Lexa, Little Rock Robinsonville, Rome, Rosedale, Sarah, (press report), Lonoke, Mabel vale, Sardis, Scobey, Sherman, Taylor, Thaxton, Madison, Mammoth Spring (press report), Tie Plant, Tiplersville, Toccopola, Tula, Mayflower, Moko, Monroe, Newburg, Tunica, Victoria, Walls, Waterford, Water Pangburn, Patterson, Pleasant Plains, Valley, Webb. Pollard, Poughkeepsie, Prim, Redfield, Missouri Alton, Bakersfield, Blodgett, Romance, Roseland, Russell, Sage, Saint Bloomfield, Bradleyville, Bragg City, James, Salem, Scotland, Sherrill, Sidney, Braggadocio, Briar, Broseley, Brownwood, Steprock, Stuttgart, Success, Sulphur Canalou, Cardwell, Charleston, Clarkton, Rock, Tichnor, Tumbling Shoals, Tupelo, Conran, Cooter, Couch, Deering, Dexter, Viola, Wabash, Ward, Wilburn, Wynne, Doniphan, Dudley, Ellington, Fairdealing, Zion. Fisk, Fremont, Gibson, Gideon, Gipsy, Illinois Akin, Belleville (press report), Gobler, Grayridge, Greenville, Cairo (press report), Centralia, Hardenville, Harviell, Hayti, Coulterville, Donnellson, Fairmont City, Hendrickson, Hiram, Holcomb, Holland, Hillsboro, Madison County (press report), Hornersville, Kennett, Kewanee, Kinder, Valmeyer, Washington Park (press report). Maiden (telephone service Kentucky Arlington, Bardwell, Barlow, disrupted press report), Mill Spring, Boaz, Cadiz, Carrsville, Cunningham, Montier, Mountain Grove, Mountain View, Eddyville, Hamlin, Hickman, Hickory, Myrtle, Neelyville, Oxly, Pascola, Jackson Purchase (press report), Kevil, Patterson, Peace Valley, Perkins, Kirksey, Lynn Grove, Lynnville, Paducah, Piedmont, Pomona, Qulin, Risco, Rives, South Fulton (press report), Wickliffe. Senath, Sikeston, Sturdivant, Tallapoosa, Mississippi Byhalia, Cascilla, Clarksdale,

14 Arkansas Contlnued Arkansas Continued

Court!and, Crowder, Enid, Grenada, Horn Arkansas Barton, Bass, Brockwell, De Witt, Lake (powerlines down press report), El Paso, Greenbrier, Leslie, Ulm. Independence, Indianola (momentary power Illinois Belle Rive, Cutler, Godfrey, failure press report), Lafayette Michael. Springs, Lambert, Merigold, Mount I ndi ana Evansvi lie. Pleasant, Myrtle, New Albany (powerlines Kentucky Bandana, Benton, Kuttawa, down, telephone service Ledbetter. interrupted press report), Oakland, Mississippi Carrol 1 ton, Farrell, Paris, Randolph, Rena Lara, Ripley, Jonestown, Pope, Rich, Sledge, Sumner. Savage, Schlater, Senatobia, Shelby, Missouri Barnett, Whiteman AFB. Sherard, Si don, Slate Spring, Sunflower, Oklahoma Tulsa (press report). Swiftown, Tillatoba, Tippo, Tutwiler, Tennessee Cades, Cunningham, Gibson, Vance, Vicksburg (press report). Gleason, Henry County (hundreds of Missouri Advance, Anniston, Ava, Bell calls press report), Nashville (press City, Bel If lower, Bertrand, Birch Tree, report), New Johnsville (press report), Bonnots Mill, Brighton, Cape Girardeau Paris (press report). (press report), Caruthersville (press report), Caul field, Chamois, 25 March (S) Northeastern Arkansas Chesterfield, Conway, Des Arc, Dittmer, Origin time: 01 00 11.9 Eminence, Essex, Gatewood, Grandin, Epicenter: 35.61 N., 90.48 W. Hocomo, Howards Ridge, Jackson (press Depth: 15 km report), La Due (press report), Lanton, Magnitude: 4.5 ML Lodi, Matthews, McGee, Moody, Morehouse, Intensity II: Felt in several towns. Naylor, New Haven, Oran, Painton, Parma, Poplar Bluff, Portland, Richmond Heights 25 September (S) Northeastern Arkansas (press report), Shook, St. Charles County Origin time: 14 06 56.0 (press report), Tecumseh, Udall, Epicenter: 35.61 N., 90.45 W. University City (press report), Depth: 5 km Wappapello, Williamsville, Wolf Island. Magnitude: 3.6 mbLg Tennessee Atoka, Buchanan, Bumpus Mills, Intensity V: Camden (press report), Chattanooga (press Arkansas Lepanto, Payneway (small objects report), Columbia (press report), Como, and furniture moved), Trumann, Tyronza Cordova, Cottage Grove, Cunningham, (small objects moved). Daisy, Dover, Dresden, Eads, Eaton, Tennessee Macon, Memphis. Elbridge, Enville, Finger, Flintville, Intensity IV: Frayser (press report), Humboldt, Huron, Arkansas Marked Tree, Riverdale. Indian Mound, Jacks Creek, Kenton, Missouri Deering. Lafayette, Linden, Lobelville, Martin, Intensity II: McEwen, McNairy, Milan, Moscow, Oakland, Arkansas Hunter, Swifton. Palmersville, Puryear, Raleigh Springs (people left the cinema press report), Sharon, Springereek, Stanton, Tigrett, California Toone, Trezevant, Union City, Whiteville. Intensity III; Alabama Belle Mina, Birmingham (press 1 January (P) Southern California report), Limestone (press report), Origin time: 17 20 12.9 Rogersville. Epicenter: 33.97 N., 117.88 W. Arkansas Cozahome, Des Arc, Evening Shade, Depth: 6 km Fifty Six, Huff, Midway, Oneida, Wolf Magnitude: 4.2 ML, 4.6 mb(G) Bayou. Illinois Buckner, Chester (press report), This earthquake was felt in Los Angeles, DuQuoin (press report), Murphysboro Orange, Riverside, and San Bernardino (press report). Counties. It disturbed millions of Kentucky Deepwood (press report), residents but caused no injuries and did no Hopkinsville (press report), Mayfield, serious damage (press report). Minor Murray (high-rise dormitories at Murray damage was reported at Brea, Cudahy, La College were evacuated press report), Habra, Maywood and Yorba Linda. Some tele­ Oakton. phone service was interrupted (press re­ Mississippi Banner, Big Creek, Calhoun port). The USGS (Porcella, 1977) reported City, Lula, Lyon. 11 strong-motion records were obtained Missouri Bendavis, Leslie, Poynor, Saint from locations within a 14-km radius of Louis. the epicenter. The maximum recorded ac­ Tennessee Bath Springs, Bradford, celeration of 0.28 g occurred in Whittier, Charlotte, Medon. about 13.8 km west of the epicenter. Intensity II; Alabama Arab, Cardiff, Tuscumbia (press USGS canvassed an area around the epicenter report). within a radius of 60 km and mailed 158 15 Cal 1 f orni a Contl nued Cal i f orni a Conti nued

questionnaires. Figure 5 shows the results 10 January (G) California-Mexico border area of this survey. Origin time: 12 58 15.9 Epicenter: 32.05 N., 115.54 W. Depth: 33 km 119" 118" Magnitude: 4.6 mb Intensity V: California El Centro (bottles broke at Food Palace Market press), Calexico. Intensity IV; Arizona Gadsden. Intensity II: California San Diego (aftershock at 5 p.m.) 14 January (P) Southern California Origin time: 20 26 24.5 Epicenter: 33.09 N., 116.65 W. Depth: 13 km Magnitude: 3.4 ML Intensity III: San Diego (P). 14 January (B) Central California Origin time: 21 43 59.3 Epicenter: 36.11 N., 120.16 W. 33° Depth: 5 km Magnitude: 5.1 mb(G), 4.9 ML EXPLANATION Epicenter \ San Diego USGS canvassed an area around the epicenter within a radius of 200 km and mailed 290 questionnaires. Intensity VI; Avenal (Plaster cracked. Figure 5.--Area affected by southern California Light fixture fell from ceiling at earthquake of January 1 elementary school press report.). Intensity V; Mount Hamilton. Intensity IV: Cholame, Coalinga, Creston, Dos Palos, Five Points, Friant, Huron, Intensity VI; Brea (cracked fireplace; broke Kettleman City, King City, Lemoore, Lost windowpane press report), Cudahy (slight Hills, Piedra, Riverdale, Stratford, damage), La Habra (broke water pipe at High Tempieton, Westhaven, Yosemite National School, causing minor water damage; broke glass at the Pic 'N' Save and at an Park. apartment complex on La Habra Blvd.; Intensity III: Caruthers, Delano, Parkville knocked phone service out press report), (press report). Maywood (cracked windows), Yorba Linda Intensity II: Laton. (cracked walls and ceilings, toppled 14 January (B) Central California lamps press report). Origin time: 23 40 17.6 Intensity V: Anaheim, Artesia, Atwood, Epicenter: 36.14 N., 120.21 W. Azuza, Buena Park, Claremont, Compton, Depth: 2 km Duarte, Fullerton, Huntington Beach, La Magnitude: 3.4 ML Mirada, Long Beach, Los Angeles, Monrovia, Intensitby II San Joaquin Valley (press Monterey Park, Orange, Pomona, Rosemead, report).tK) Aftershock of earthquake on 14 Seal Beach, Sunset Beach, Upland (press January, 21 43 59.3 UTC. report), Walnut, West Covina, Whittier. Intensity IV: Arcadia, Baldwin Park, 15 January (B) Central California Bassett, Bel Iflower, Cerritos, Corona, Origin time: 00 09 37.4 Costa Mesa, Cypress, El Monte, El Segundo, Epicenter: 36.15 N., 120.25 W. Etiwanda, Fontana, Garden Grove, Glendale, Depth: 7 km Glendora, Hacienda Heights, Inglewood, La Magnitude: 3.5 ML Puente, Laverne, Midway City, Mira Loma, Intensity II San Joaquin Valley (press Montclair, Montebello, Mt. Baldy, Newport report). Aftershock of earthquake on 14 Beach, Norco (press report), Paramount, January, 21 43 59.3 UTC. Phelan, Placentia, San Dimas, Santa Ana, South Gate, South Pasadena, Stanton, 15 January (P) Brea, Calif. Tustin, Westminster, Wilmington. Origin time: 03 12 Intensity III; Altadena, Chino, Covina, Epicenter: None computed. Huntington Park, Lakewood, Montrose, Depth: None computed. Ontario, Silverado, Sunnymead, Temple City. Magnitude: None computed. Intensity II; Bell Gardens, Downey, Lomita, Intensity II: Anaheim, Brea, Fullerton, La Riverside, San Diego, Sierra Madre. Habra, Placentia (press report). 16 California--Cont1nued Cal1fornla--Conti nued

18 January (B) Northern California 8 March (B) Central California Origin time: 01 00 24.7 Origin time: 20 23 27.3 Epicenter: 40.64 N., 124.35 W. Epicenter: 37.39 N., 120.10 W, Depth: 23 km Depth: 2 km Magnitude: 4.0 mb(G), 3.7 ML Magnitude: 2.5 ML Intensity IV Ferndale. Intensity IV: Mariposa.

18 January (B) Northern California 9 March (B) Central California Origin time: 07 38 25.2 Origin time: 19 45 00.3 Epicenter: 39.06 N., 122.96 W. Epicenter: 37.33 N., 122.18 W, Depth: 7 km Depth: 7 km Magnitude: 2.6 ML Magnitude: 2.6 ML Intensity III: Lakeport vicinity. Intensity II: Palo Alto.

1 February (B) Northern California 14 March (P) Southern California Origin time: 02 57 39.7 Origin time: 09 32 Epicenter: 37.93 N., 122.31 W. Epicenter: None computed. Depth: 4 km Depth: None computed. Magnitude: 2.6 ML Magnitude: None computed. Intensity II; El Cerrito, Pablo, Pinole, Intensity II Glendale, Tujunga. Richmond (press report). 3 February (P) Southern California 17 March (B) Central California Origin time: 03 40 Origin time: 04 01 52.7 Epicenter: 36.83 N., 121.13 W. Epicenter: None computed. Depth: 8 km Depth: None computed. Magnitude: 4.2 mb(G), 4.3 ML Magnitude: None computed. Intensity IV Gilroy (15 km northeast of), Intensity II: Hollywood, downtown Los Angeles. 29 March (P) Southern California Origin time: 16 37 19 February (P) Southern California Origin time: 22 09 55.1 Epicenter: None computed. Epicenter: 34.39 N., 118.35 W. Depth: None computed. Depth: 9 km Magnitude: None computed. Magnitude: 3.1 ML Intensity II: Brawley (press report). Intensity III: Soledad, Sylmar (aftershock at 22:12) (P). 8 April (P) Southern California Origin time: 15 21 38.1 Epicenter: 34.35 N., 118.67 W. 24 February (B) Northern California Depth: 15 km Origin time: 15 13 10.5 Magnitude: 4.7 mb(G), 3.9 MS(G), Epicenter: 40.29 N., 124.37 W. 4.8 ML(B), 4.6 ML Depth: 6 km Magnitude: 3.5 mb(G), 3.5 ML Intensity IV; Fortuna, Kneel and. USGS canvassed an area around the epicenter within a radius of 250 km and mailed 842 1 March (B) Central California questionnaires. The earthquake was felt Origin time: 17 06 40.3 from Bakersfield to San Diego (see fig. 6). Epicenter: 37.73 N., 121.96 W, Depth: 7 km Intensity VI: Granada Hills (plaster Magnitude: 2.8 ML cracked), Inglewood (slight damage), Intensity II Dublin. Palmdale, Sylmar. Intensity V: Agoura, Arcadia, Calabasas, Chatsworth, Compton, Culver City, Encino, 4 March (B) Central California Frazier Park, Julian, Llano, Los Angeles, Origin time: 15 08 09.7 Manhattan Beach, Newbury Park, Pacoima, Epicenter: 38.79 N., 122.75 W, Palos Verdes Peninsula, Panorama City, Depth: 2 km Piru, Reseda, San Fernando, Santa Paula, Magnitude: 3.1 ML Saugus, Sierra Madre, Simi Valley, South Intensity II: Cobb. Pasadena, Surfside, Sunset Beach, Tarzana. Intensity IV: Altadena, Bakersfield, 6 March (B) Central California Burbank, Camarillo, Canoga Park, Origin time: 13 51 08.1 Carpinteria, Fill more, Hawthorne, Hermosa Epicenter: 38.83 N., 122.83 W, Beach, Lake Arrowhead, Lake Hughes, Lebec, Depth: 4 km Lomita, Long Beach, Lynwood, Malibu, Magnitude: 2.9 ML Maricopa, Midway City, Mojave, Montebello, Intensity II: Cobb. Moorpark, North Hollywood, Northridge, 17 Cal i form' a Conti nued Cali forni a--Conti nued

Epicenter 6 Felt at intensity 6

o Not felt

Figure 6.--Area affected by southern California earthquake of April 8

Pacific Palisades, Pearblossom, San Diego, The press reported that a swarm of 100 small San Gabriel, Santa Monica, Seal Beach, earthquakes occurred in Imperial Valley Sepulveda, Sun Valley Thousand Oaks, following this earthquake. Topanga, Valyermo, Ventura. Intensity III: Juniper Hills, Lakewood, 14 April (P) Southern California Monrovia, Montrose, New Cuyama, Oxnard, San Origin time: 07 59 27.8 Bernardino, Venice, Woodland Hills. Epicenter: 32.88 N., 115.55 W. Intensity II; Balboa Beach area (press Depth: 8 km report), Hollywood (press report), Newhall Magnitude: 3.6 ML (press report), San Pedro, Santa Barbara Intensity III: El Centre. (press report). Intensity II: Brawley.

14 April (P) Southern California 14 April (P) Southern California Origin time: 06 56 03.9 Origin time: 10 31 00.8 Epicenter: 32.87 N., 115.48 W. Epicenter: 32.88 N., 115.48 W. Depth: 14 km Depth: 8 km Magnitude: 4.2 mb(G), 3.8 ML Magnitude: 4.0 mb(G), 3.9 ML Intensity III El Centre. Intensity III: El Centre. Intensity II; Brawley. Intensity II; Brawley.

18 Cal i form' a--Conti nued Cal i foml a--Conti nued

14 April (P) Southern California 4 May (P) Southern California Origin time: 10 47 53.6 Origin time: 13 09 Epicenter: 32.93 N., 115.55 U. Epicenter: None computed. Depth: 8 km Depth: None computed. Magnitude: 3.7 ML Magnitude: None computed. Intensity III: El Centro. Intensity II: Newhall. Intensity II; Brawley. 14 April (P) Southern California 10 May (P) Southern California Origin time: 13 23 59.4 Origin time: 10 24 24.0 Epicenter: 33.12 N., 115.50 W, Epicenter: 34.46 N., 116.88 W. Depth: 19 km Depth: 8 km Magnitude: 3.3 ML Magnitude: 3.8 mb(G), 3.6 ML Intensity III El Centro. Intensity IV: Victor Valley. Intensity II: Brawl ey. Intensity III; Lucerne Valley, Victorville. 15 April (P) Southern California 12 May (P) Southern California Origin time: 04 59 32.8 Origin time: 01 54 39.0 Epicenter: 34.37 N., 118.67 W. Epicenter: 34.36 N., 118.67 W. Depth: 15 km Depth: 14 km Magnitude: 3.1 ML Magnitude: 3.2 ML Intensity II Woodland Hills. Intensity III: Canoga Park, Newhall 16 April Near Avenal, Calif. 12 May (P) Southern California Origin time: 09 20 Origin time: 03 32 06.7 Epicenter: None computed. Epicenter: 34.36 N., 118.66 W. Depth: None computed. Depth: 15 km Magnitude: None computed. Magnitude: 3.1 ML Intensity IV Near Avenal (Kings County). Intensity III: Canoga Park, Newhall, Simi Valley. 16 April (B) Northern California Origin time: 17 11 50.6 20 May (B) Central California Epicenter: 39.56 N, 121.61 W Origin time: 04 32 38.6 Depth: 5 km Epicenter: 36.89 N., 121.49 W, Magnitude: 3.0 ML(E), 2.7 ML Depth: 2 km Intensity II Oroville area (press report). Magnitude: 3.0 ML Intensity V: Hoi lister. 25 April (P) Southern California Intensity IV: Tres Pinos. Origin time: 17 51 08.4 Intensity II: Mount Hernion. Epicenter: 33.74 N., 118.02 W. Depth: 11 km 27 May (B) Northern California Magnitude: 3.0 ML Origin time: 17 01 07.4 Intensity III: Huntington Harbor, Long Beach, Epicenter: 38.39 N., 122.68 W. Seal Beach, parts of Orange County (press Depth: 2 km report). Magnitude: 3.4 ML Intensity II: Buena Park, Cypress (press report). Intensity IV; Santa Rosa (10 km southeast), 26 April (P) Southern California Intensity III: Cotati (press report), Origin time: 06 46 36.5 Petaluma, Rohnert Park (press report). Epicenter: 33.13 N., 115.67 W. Depth: 2 km 3 June (P) Southern California Magnitude: 3.8 ML Origin time: 08 26 Intensity III: Brawley. Epicenter: None computed. Depth: None computed. 3 May (B) Northern California Magnitude: None computed. Origin time: 05 42 38.9 Intensity II Acton, Glendale. Epicenter: 38.14 N., 121.95 W. Depth: 26 km Magnitude: 3.4 ML 14 June (B) Northern California Intensity VI Fairfield (plaster cracked). Origin time: 23 30 26.5 Intensity_____ V: Birds Landing, Clayton, Epicenter: 39.47 N., 121.54 W. Crockett, Orinda, Pittsburg, Port Costa, Depth: 7 km Suisun City, Vallejo, Yountville. Magnitude: 3.9 mb(G), 3.8 ML Intensity IV: Elmira, Rio Vista, Walnut Creek. Intensity V: Biggs, Brownsville, Dobbins, Intensity III Martinez. Gold Run, Meadow Vista, Nelson, Palermo, Intensity II: Concord, San Francisco, Rackerby, Richardson Springs, Sheridan, Yacaville. Storrie, Wendel. 19 Cal i form' a Contl nued Cal i form' a Conti nued

Intensity IV; Alta, Browns Valley, 3 July (B) Northern California Challenge, Clipper Mills, College City, Origin time: 19 45 20.4 Durham, Forbestown, Gridley, Magalla, Epicenter: 40.39 N., 120.58 W. Mllford, Nevada City, North San Juan, Depth: 5 km Oroville, Penn Valley, Pulga, Richvale, Magnitude: 4.4 mb(G), 3.8 ML Smartvllle, Strawberry Valley (sudden loss Intensity V; Litchfield (small objects of water flow from spring unconfirmed), moved). Taylorsville, Wheatland. Intensity IV: Strawberry Valley. Intensity III: Twain. IntensltyTT: Janesville, Susanville. Intensity II: Dutch Flat, Forest Ranch, Herlong. 6 July (G) Northern California 17 June (P) Southern California Origin time: 03 55 16.2 Origin time: 11 04 Epicenter: 39.40 N., 121.60 W. Epicenter: None computed. Depth: 5 km Depth: None computed. Magnitude: 4.5 mb, 4.1 ML(B) Magnitude: None computed. Intensity V; Camptonville (small objects Intensity II: Bodfish. moved), Dobbins, Fair Oaks, Forbestown (small objects moved), Oroville (small 20 June (B) Northern California objects moved), Marysville (small objects Origin time: 10 15 24.8 moved), Rio Oso (small objects moved). Epicenter: 40.43 N., 120.57 W. Intensity IV; Bangor, Browns Valley, Chico, Depth: 5 km Col fax, Grass Valley, Gridley, Loomis, Magnitude: 4.4 mb(G), 4.5 ML Meadow Vista, Nevada City, Rackerby, Sheridan, Smartville, Weimar, Wheatland. This epicenter is located near Susanville, Intensity III: Strawberry Valley, Sutter, Lassen County, 1n the vicinity of the Trowbridge. Antelope Mountain-Litchfield faults. Intensity II: Meridian, Richvale, Sacramento Several aftershocks were recorded (B). (press report), Twain, Yuba City (press report). Intensity V; Objects were knocked from walls and many awakened in the following 7 July (B) Central California communities (press report): Chllcoot, Origin time: 07 50 45.4 Eagle Lake, Janesville, Susanville, Epicenter: 37.44 N., 121.77 W. Washington, Wendel (2-1/2 km east of), Depth: 10 km Westwood, Willow Creek. Magnitude: 3.5 ML Intensity IV: Mt. Hamilton, San Jose, Intensity IV: Mil ford, Taylorsville. Sunnyvale, Willow Glen (press report). Intensity III: Campbell (press report), 24 June (B) Northern California Fremont (press report), Santa Clara (press Origin time: 15 44 45.4 Epicenter: 40.39 N., 120.59 W. report). Depth: 5 km 8 July (B) Northern California Magnitude: 4.7 mb(G), 4.2 ML Origin time: 16 14 10.5 Intensity V; Lltchfield, Standish Epicenter: 40.10 N., 124.00 W. (foresnock felt at 10:15 which might Depth: 2 km pertain to the June 20 event in the same Magnitude: 2.9 ML area), Susanville, Wendel. Intensity IV: Petrolia. Intensity IV; Janesville, Keddie. 13 July (B) Northern California 27 June (P) Southern California Origin time: 13 34 53.7 Origin time: 22 11 36.7 Epicenter: 38.09 N., 121.87 W. Epicenter: 34.05 N., 118.30 W. Depth: 10 km Depth: 8 km Magnitude: 3.7 ML Magnitude: 2.9 ML Felt throughout sections of Contra Costa, Intensity III; Beverly Hills, Culver City, Sacramento, and Solano Counties (press Glendale, Griffith Park, Hollywood, Los report). Angeles (airport and downtown), Pasadena, Santa Monica, Venice, Wilshire-Crenshaw Intensity V: Pittsburg (small objects moved) area (all press reports). Intensity IV; Birds Landing, Diablo, Rio 29 June (P) Southern California Vista. Origin time: 06 44 54.6 Intensity III; Antioch, Collinsville (press Epicenter: 33.96 N., 116.58 W. report). Depth: 8 km Intensity II: Bethel Island (press report), Magnitude: 3.0 ML Byron, Concord, Fairfield (press report), Intensity II; Palm Springs. Hood, Martinez, Ryde, Walnut Creek. 20 Cal1fornla Contlnued Cal1fornla--Continued

18 July (B) Central California State Park), Indio (slight damage; one Origin time: 11 49 28.4 resident became nauseous press report), Epicenter: 37.28 N., 122.17 W. Palm Desert (cement curb raised 5 cm, Depth: 10 km causing buckling). Magnitude: 2.6 ML Intensity V; Angel us Oaks (postmaster Intensity V; Los Altos Hills (stained glass sitting in car in parking lot reported, windows cracked press report). "The trees and surrounding area...made a strange sound as if the wind were blowing. 23 July (P) Southern California The animals and birds were very still, and Origin time: 20 53 55.9 the building creaked somewhat. My vehicle Epicenter: 33.87 N., 118.13 W. bounced...for about 30-40 seconds and then Depth: 11 km began to slow down as the suspension Magnitude: 3.1 ML stopped the vibrations."), Anza, Big Bear Intensity IV; Lakewood (shook desk City (small objects moved). Cathedral City, lamps--press report). Hemet, Idyllwild, Laguna Niguel (report Intensity III: (Press reports) Bell flower, from observer on fifth floor of six-story Compton, North Long Beach. Federal Building stated that 13 of 18 people felt the shock. Duration was 26 July (B) Northern California estimated to be 2-3 seconds, with two Origin time: 13 50 05.0 shocks 8-10 seconds apart. Hanging Epicenter: 36.37 N., 121.17 W. planters and pictures swung from east to Depth: 6 km west. Some people frightened; some became Magnitude: 2.3 ML dizzy), Mecca, North Palm Springs, Potrero, Intensity IV; Pinnacles National Monument Ranchita (small objects displaced), San (east side, headquarters area). Diego, San Jacinto, San Luis Rey Downs, Temecula, Thousand Palms, Warner Springs. 26 July (B) Northern California Intensity IV; Alpine (goats reacted before Origin time: 14 00 01.7 the earthquake), Cabazon, Coachella, Epicenter: 36.55 N., 121.17 W. Escondido, Julian, La Quinta, Mead Valley, Depth: 6 km Moreno, Morongo Valley, Mountain Center, Magnitude: 2.0 ML Muscoy, North Shore, Pal a, Palm Springs, Intensity IV; Pinnacles National Monument Rancho Mirage, Sal ton City, Thermal, White (east side, headquarters area). Water, Winchester, Yucca Valley. Intensity III; Cuyamaca (felt at caretaker's 1 August (P) Southern California home, on State Highway 79 at south end of Origin time: 17 18 48.1 Cuyamaca Dam), Murrieta, Riverside, Santa Epicenter: 34.90 N., 116.58 W. Ysabel. Depth: 12 km Intensity II; Bonsai 1, Homeland, North Park. Magnitude: 4.5 ML Intensity V; Daggett, Newberry Springs. 12 August (B) Central California Intensity IV; Landers, Yermo. Origin time: 08 51 11.3 Intensity II; Baker. Epicenter: 37.17 N., 121.53 W. Depth: 7 km 9 August (P) Southern California Magnitude: 3.2 ML Origin time: 10 54 30.0 Intensity IV Pinnacles National Monument Epicenter: 34.33 N., 118.52 W. (windows rattled at headquarters building; Depth: 8 km light fixtures squeaked but did not swing), Magnitude: 2.8 ML Storrie. Intensity II: Northridge. 15 August (B) Central California 11 August (P) Southern California Origin time: 12 29 05.6 Origin time: 15 24 55.5 Epicenter: 37.79 N., 121.96 W. Epicenter: 33.48 N., 116.52 W. Depth: 7 km Depth: 15 km Magnitude: 3.3 ML Magnitude: 4.3 ML The press reported that seven earthquakes USGS canvassed an area around the epicenter occurred within 2 1/2 hours after this within a radius of 200 km and mailed 642 shock near Danville in Contra Costa County. questionnaires. The earthquake was felt in San Bernardino, San Diego, Orange, and Intensity V: Castro Valley (small objects Imperial Counties, over an area of about moved), Danville, Diablo (3 tremors felt 15,500 sq km (fig. 7). from 3 to 5 a.m.), San Lorenzo. (Many were awakened and frightened in these Intensity VI: Borrego Springs (ground communities.) cracked in "fault wash" in east part of Intensity IV; Walnut Creek (several Anza-Borrego State Park; also some aftershocks felt between 3:10-5:30 a.m; mudslides reported by acting manager of radio station reported windows shattered in 21 Cal i forni a Conti nued Cal i forni a Conti nued

118' 116' 117

Figure 7. Area affected by southern California earthquake of August 11

one house unconfirmed). reported felt throughout the San Francisco Intensity II: Dimond. Bay area. Plaster reportedly was cracked in some Danville homes (B). 16 August (F) California-Nevada Border Region Origin time: 16 37 21.4 Intensity VI: Danville (plaster reported Epicenter: 36.19 N., 117.66 W. cracked in homes) (B). Depth: 8 km Intensity IV: Alameda, Dublin (press Magnitude: 3.7 ML(B), 3.7 ML(P) report). Intensity V; Darwin. Intensity III: Berkeley (press report), El derrito, Walnut Creek. 20 August (B) Central California Intensity II: Daly City, Dimond, Hayward, Origin time: 22 05 52.9 Martinez, Oakland, Pittsburg, Pleasanton, Epicenter: 37.79 N., 121.97 W. San Francisco, San Ramon, Sunol. (All Depth: 7 km press reports except Dimond and Oakland.) Magnitude: 4.0 ML 2JQ August (B) Central California This was the largest earthquake of two swarms Origin time: 22 08 01.1 that occurred Aug. 15-16 and 20-22. They Epicenter: 37.76 N., 121.91 W. centered in the same general area as the Depth: 2 km swarm in June 1970. The epicenter is Magnitude: 3.9 ML located about 24 km southeast of Berkeley, in the area of Danville, in the vicinity of Felt throughout the San Francisco Bay area. the Calaveras fault system. It was The August 20 earthquake (at 22:05 UTC) was 22 Cal1fornla Conti nued Cali fornia--Continued

canvassed. Only one respondent mentioned 6 October (B) Central California that the same effects were felt for both Origin time: 20 54 19.9 shocks. Epicenter: 37.63 N., 121.42 U. Depth: 2 km Intensity IV: Danville, Dublin (press Magnitude: 3.0 ML report).Intensity II: Stockton, Tracy. oo . j. in\ r *L. r T* 9 October (P) Southern California 22 August (P) Southern California Ori - n time: 02 09 28.1 Origin time: 08 09 59.7 Epicenter: 33.33 N., 116.23 W. Epicenter: 34.03 N., 117.47 W. DJ th . lfi km P/Pth i . I SmM, Magnitude: 3.9 ML Magnitude: 3.0 ML Intensity III; Cuyamaca (north San Diego Intensity IV: Etiwanda. r t < J y Intensity III: (Press reports) Fontana, San uiuntyj. Bernardino. 15 October (B} Northern California 1 September (B) Northern California ?1?l"t*!.'!ie: m I1 '* 199 M u Origin time: 22 42 48.8 Epicenter: 38.01 N., 122.05 W. Epicenter: 40.64 N., 122.21 W. M P -1 ^ 1 /I, Depth- 5 km Magnitude: 3.4 ML Magnitude: 3.5 ML Intensity III; Concord, Orinda, Walnut Intensity IV; Central Valley,ass. French611" Gulch,Red »-°-

119' 118C

EXPLANATION

Epicenter

7 Felt at intensity 7

O Not felt

Figure 8. Area affected by southern California earthquake of October 17

22 October (P) Southern California Depth: 15 km Origin time: 23 19 13.6 Magnitude: 3.4 ML Epicenter: 33.48 N., 116.58 W. Intensity IV: Fortuna, Rio Dell, Scotia. Depth: 15 km (Buildings creaked in all three towns.) Magnitude: 4.5 mb(G), 3.6 ML Intensity II; Palm Springs (press report) 2 November (P) Southern California Origin time: 02 46 05.9 23 October (B) Central California Epicenter: 34.10 N., 117.30 W. Origin time: 19 24 33.2 Depth: 6 km Epicenter: 36.89 N., 121.49 W. Magnitude: 3.3 ML Depth: 11 km Magnitude: 3.5 ML USGS evaluated a questionnaire canvass of Intensity II Gilroy, Hoi lister. University of Redlands students; the results are listed below. 24 October (B) Central California Origin time: 02 19 52.7 Intensity V: Loma Linda (frightened many Epicenter: 36.84 N., 121.63 W. in Loma Linda Hospital), Redlands Depth: 2 km (frightened students in dormitory of Magnitude: 3.5 ML University of Redlands), San Bernard!no Intensity II Gilroy, Hollister. (picture fell from wall in southernmost part of city). 26 October (B) Northern Californa Intensity IV: Highland, Rial to, Yucaipa. Origin time: 23 23 44.8 Intensity III: Norton Air Force Base Epicenter: 40.30 N.. 124.27 W. ftelepnone report). 24 California Continued California Continued

4 November (P) Southern California 4 November (F) Southern California Origin time: 04 33 45.9 Origin time: 10 41 37.5 Epicenter: 34.05 N., 116.38 W, Epicenter: 33.12 N., 115.59 W. Depth: 8 km Depth: 4 km Magnitude: 3.2 ML Magnitude: 4.6 mb(G), 5.3 MS(G), Intensity IV Morongo Valley. 4.9 ML(P), 5.5 ML(B)

4 November (F) Southern California Thirty earthquakes of magnitude 2 to 4 oc­ Origin time: 05 48 20.9 curred between 8:00 p.m. and 11:30 p.m. Epicenter: 33.12 N., 115.60 W. PST (press report). One hundred earth­ Depth: 5 km quakes were recorded at California Insti­ Magnitude: 4.2 ML(P) Intensity II tute of Technology in a 24-hour period Imperial Valley. (press report). The earthquake trigger­ ed burglar alarms in several Imperial 4 November (F) Southern California Valley communities (press report). The Origin time: 06 35 03.5 main shock was felt over an area of about Epicenter: 33.12 N., 115.59 W. 25,000 sq km (fig. 9) of the southern Depth: 5 km California-western Arizona region. Slight Magnitude: 4.1 ML(P) damage occurred at Brawley, El Centre, and Intensity II: Imperial Valley. Westmorland. No intensity data are avail­ able from Mexico. 4 November (F) Southern California Intensity VI: Origin time: 07 56 06.8 Cal i form'a Brawl ey (plaster and dry wall Epicenter: 33.12 N., 115.61 W, cracked; bottles and jars falling from Depth: 1 km market shelves caused about $200 Magnitude: 3.9 ML(P) damage press report), El Centro Intensity II: Imperial Valley. (fences displaced slightly, furniture

118

EXPLANATION Epicenter 7 Felt at intensity 7 o Not felt CALIFORNIA 0

5 5 l6JElCen1ro ___._ *- '-

MEXICO

Figure 9.--Area affected by southern California earthquake of November 4 25 California Continued Cal i forma Continued

moved, plaster and ceiling tiles Depth: None computed. cracked), Westmorland (large appliances Magnitude: None computed. displaced, ground cracked, plaster Intensity V: Willets (small objects and cracked, electric service interrupted furniture moved). in area). Intensity V: 15 November (P) Southern California Anzona--San Luis (furniture moved), Yuma Origin time: 12 08 04.0 (press report). Epicenter: 33.93 N., 118.25 W. Caliform'a--Anza, Bard, Blythe, Boulevard Depth: 8 km (5 km west of, at Live Oak Springs), Magnitude: 2.9 ML Cabazon, Calexico, Chiriaco Summit Intensity III: Culver City, Gardena, (small objects moved), Guatay, Heber, Inglewood. Imperial, Julian, Lost Lake (50 km north of Blythe), Mount Laguna, Nil and, 22 November (P) Southern California Ocotillo (furniture moved), Palo Verde, Origin time: 17 55 10.8 Pine Valley, Plaster City, Ripley (3 km Epicenter: 33.95 N., 118.62 W. north of), Seeley, Thermal, Winterhaven Depth: 2 km (5 km northeast of). Magnitude: 3.8 ML Intensity IV: California Campo, Cuyamaca, Indio, San This earthquake was felt over an area of Diego. approximately 4,000 sq km (fig. 10) along Intensity III: the coast of California west of Los California Bonita (press report), Chula Angeles. Vista (press report), Palm Desert, Valley Center. Intensity VI: Long Beach (slight damage; Intensity II: trees and bushes shook), Los Angeles California--Bryn Mawr, Potrero, Rancho (plaster cracked), North Hollywood Mirage, San Bernardino. (plaster cracked, windows broken, furniture moved). 4 November (F) Southern California Intensity V: El Segundo, Fillmore, Origin time: 11 39 08.3 Hawthorne, Hermosa Beach, Inglewood, Epicenter: 33.10 N., 115.62 W. Lynwood, Playa del Rey (small objects Depth: 1 km moved), Redondo Beach, Santa Monica, Magnitude: 4.1 ML(P) Sepulveda (small objects moved), Sherman Intensity II: Imperial Valley. Oaks (small objects moved), Topanga, Torrance (small objects moved), Venice, 4 November (F) Southern California West Los Angeles, Woodland Hills. Origin time: 11 49 40.4 Intensity IV: Burbank, Canoga Park, Epicenter: 33.11 N., 115.62 W. Chatsworth, Culver City, Downey, Encino, Depth: 2 km Gardena (press report), Granada Hills, Magnitude: 3.8 mb(G), 4.1 ML(P) Huntington Park, Lakewood, Mission Hills, Intensity II: Imperial Valley. Montebello (press report), Mount Baldy, Northridge, Norwalk, Pacific Palisades, 4 November (F) Southern California Rosemead, Simi Valley, Somis, South Gate, Origin time: 13 31 27.7 Sylmar (press report), Thousand Oaks, Van Epicenter: 33.10 N., 115.62 W. Nuys, Westwood, Wilmington. Depth: 4 km Intensity III: La Palma (press report), Magnitude: 4.2 ML(P) Pasadena, Piru. Intensity II: Imperial Valley. Intensity II: Malibu. 4 November (F) Southern California 22 November (P) Southern California Origin time: 14 12 50.2 Origin time: 19 32 36.8 Epicenter: 33.12 N., 115.60 W. Epicenter: 33.97 N., 118.58 W. Depth: 5 km Depth: 8 km Magnitude: 4.2 mb(G), 4.4 ML(P) Magnitude: 2.9 ML Intensity II: Imperial Valley. Intensity II: Los Angeles, Santa Monica. 5 November (B) Central California 27 November (F) Southern California Origin time: 19 43 11.0 Origin time: 15 23 43.1 Epicenter: 35.80 N., 121.30 W. Epicenter: 33.50 N., 116.49 W. Depth: 2 km Depth: 5 km Magnitude: 3.5 ML Magnitude: 3.3 ML(P) Intensity II; San Simeon. Intensity-II: Palm Springs. 11 November Northern California 30 November (P) Southern California Origin time: 02 32 Origin time: 23 55 18.8 Epicenter: Not located. Epicenter: 34.08 N., 118.28 W. 26 California Continued California Continued 119°

Figure 10. Area affected by southern California earthquake of November 22 EXPLANATION VV Epicenter

7 Felt at intensity 7

o Not felt

Depth: 8 km Intensity II: Riverside County (press Magnitude: 2.5 ML report), San Bernardino County (press Intensity III: Hollywood, Los Angeles report). downtown area. 17 December (B) Northern California 5 December (P) Central California Origin time: 21 36 28.4 Origin time: 04 41 08.9 Epicenter: 38.77 N., 122.27 W. Epicenter: 35.39 N., 118.68 W. Depth: 2 km Depth: 1 km Magnitude: 3.3 ML Magnitude: 3.8 ML Intensity II Geyserville. Intensity V: Keene. Intensity fl: Walkers Basin (near Caliente). California Off the coast 7 December (P) Baja California Origin time: 12 59 56.3 Epicenter: 31.98 N., 114.78 W. 20 January (G) Northern California Depth: 8 km Origin time: 13 59 37.2 Magnitude: 5.5 mb(G), 5.7 MS(G), 5.2 ML Epicenter: 40.38 N., 125.34 U. Depth: 33 km See Arizona listing for intensity data. Magnitude: 4.8 mb, 4.7 ML(B) Intensity IV Eureka, Ferndale, Petrol ia 8 December (P) Southern California (press report). Origin time: 02 13 44.1 Epicenter: 34.47 N., 118.42 U. Depth: 12 km Magnitude: 3.3 ML Intensity II: San Fernando. 22 May (G) Northern California Origin time: 00 51 41.4 9 December (P) Southern California Epicenter: 40.40 N., 125.35 W. Origin time: 17 11 36.3 Depth: 33 km Epicenter: 33.98 N., 117.25 U. Magnitude: 3.9 mb, 3.4 ML(B) Depth: 11 km Intensity V: Fortuna. Magnitude: 2.9 ML IntensityTV: Miranda, Salmon Creek.

27 California Off the Coast Continued California Off the Coast Continued

13 September (B) Northern California 18 October (P) Southern California Origin time: 17 26 52.6 Epicenter: 32.72 N., 117.92 W. Origin time: 16 08 10.2 Depth: 15 km Epicenter: 40.20 N., 124.39 W. Magnitude: 4.6 mb(G), 4.2 ML Depth: 1 km Magnitude: 4.8 mb{G), 4.0 ML Felt in western San Diego and Orange Intensity IV: Ferndale, Petrolia, Scotia. Counties. Intensity TTl: Rio Dell. Intensity III; Newport Beach, San Diego.

126

41

40

39

Figure 11.--Area affected by northern California earthquake of November 26 28 California Off the Coast Continued Georgia Continued

26 November (G) Northern California UTS; and January 5, 1977, 02 32 UTC Origin time: 11 19 25.2 were reported by Lance et al. (1977). Epicenter: 41.29 N., 125.71 W. Depth: 15 km Intensity V; Baxley, Hazel hurst, Magnitude: 6.0 mb, 6.8 MS, 6.2 ML(B) Reidsville, Uvalda (pictures tilted). Intensity IV: Cedar Crossing (oral This earthquake was felt over an area of commun.), Fitzgerald, Jeykll Island about 6,500 sq km (fig. 11, on p. 28) along ("wind blowing fiercely, loud the coast north and south of Eureka. thunderclap, followed one-half minute later by loud noise as if heavy boots Intensity V: were dropped above"), Lyons. California Arcata- (small objects moved), Bayside, Blocksburg, Blue Lake, Burnt Ranch, Cedar Ridge, Crescent City (press report), Eureka, Ferndale, Hawaii Honeydew, Humboldt (press report), Klamath, Loleta, McKinleyville (press report), Petrolia, Samoa, Weott. Intensity IV: 1 January (H) Island of Hawaii California Carl otta (3 km east of), Origin time: 18 54 23.0 Comptche, Fort Bragg, Horse Creek, Epicenter: 18.85 N., 155.08 W. Kneel and, Mount Shasta, Rio Dell Depth: 26 km (observer said all effects exaggerated Magnitude: 4.5 ML in the press and on radio), Scott Bar, Intensity III: Kalapana (H). Trinidad. Intensity II; Kona (H), Naalehu (H) Oregon Brook i ngs. Intensity III: 2 January (H) Island of Hawaii Cali,form'a--Hydesvilie, Orick. Origin time: 01 36 47.2 Oregon--Merlin. Epicenter: 19.36 N., 155.25 W. Intensity II: Depth: 9 km Cali form'a--Denny. Magnitude: 3.5 ML Oregon Eugene (telephone report). Intensity III: Volcano (H). Washington Long View (telephone report). 7 January (H) Island of Hawaii Origin time: 11 44 33.2 Connecticut Epicenter: 19.45 N., 154.88 W. Depth: 9 km Magnitude: 3.8 ML 24 April (C) Central Connecticut Intensity III; Pahoa (H). Origin time: 10 22 22.1 Epicenter: 41.68 N., 72.49 W. Depth: 0 km 12 January (H) Island of Hawaii Magnitude: 2.2 mbLg Origin time: 00 05 40.1 Epicenter: 19.51 N., 155.27 W. A smaller foreshock was reported on April 6, Depth: 24 km an aftershock on April 30 (press report). Magnitude: 4.2 ML, 4.5 mb(G), 4.2 MS(G) ______Intensity IV Felt Islandwide (houses shaken Intensity IV: Haddam, Snailervilie (awakened on the eastern side of the Island of a few people press report). Hawaii press report), Hilo (H), Puna (H). Intensity III: Kau (H). Intensity II; Kamuela (H), Kona (H). Georgia 12 January (H) Island of Hawaii Origin time: 13 48 32.9 Epicenter: 19.37 N., 155.12 W. 27 December (G) Southeastern Georgia Depth: 9 km Origin time: 06 57 13.9 Magnitude: 3.0 ML Epicenter: 32.22 N., 82.46 W. Intensity III: Nanawale (H). Depth: 5 km Magnitude: 3.7 mbLg(V) 14 January (H) Island of Hawaii The intensities listed below are from a Origin time: 22 09 51.9 USGS questionnaire canvass and a report Epicenter: 19.38 N., 155.11 W, by Lance et al. (1977). Three small Depth: 7 km aftershocks that occurred on December 28, Magnitude: 2.3 ML 1976, 22 17 UTC; January 5, 1977, 02 30 Intensity II; Volcano (H). 29 Hawaii Continued Hawaii Continued

15 January (H) Island of Hawaii Intensity III: Hilo (H). Origin time: 22 41 45.2 Intensity II; Honomu (H), Kalapana (H), Epicenter: 19.41 N., 155.29 W. Papalkou (H), Volcano (H). Depth: 14 km Magnitude: 4.4 ML 23 January (H) Island of Hawaii Intensity V: Hilo (H). Origin time: 12 47 40.0 Intensity IV: Other parts of Hawaii Island Epicenter: 19.36 N., 155.09 W. (H). Depth: 9 km Intensity II: Oahu Island (H). Magnitude: 3.7 ML Intensity III: Hilo (H), Puna (H). 15 January (H) Island of Hawaii IntensityTTT Kahuku (H), Volcano (H). Origin time: 22 59 26.0 Epicenter: 19.41 N., 155.29 W. 27 January (H) Island of Hawaii Depth: 16 km Origin time: 15 35 51.3 Magnitude: 4.8 mb(G), 4.5 ML Epicenter: 19.35 N., 155.10 W. Intensity V: Hilo (H). Depth: 9 km Intensity IV: Other parts of Hawaii Island Magnitude: 3.6 ML (H). Intensity III: Hilo (H). Intensity III Felt Islandwide (press Intensity II: Glenwood (H), Keaau (H), report). Kurtistown (H), Volcano (H). Intensity II: Oahu Island (H). 27 January (H) Island of Hawaii 17 January (H) Island of Hawaii Origin time: 21 34 04.5 Origin time: 05 29 13.8 Epicenter: 19.34 N., 155.09 W. Epicenter: 19.38 N., 155.11 W. Depth: 7 km Depth: 8 km Magnitude: 2.9 ML Magnitude: 3.7 ML Intensity II: Hawaii National Park (H) Intensity IV: Hilo (H) Intensity"!!"!: Puna (H), Volcano (H), 28 January (H) Island of Hawaii Origin time: 08 26 28.1 17 January (H) Island of Hawaii Epicenter: 19.34 N., 155.11 W. Origin time: 06 00 03.9 Depth: 9 km Epicenter: 19.35 N., 155.00 W. Magnitude: 4.0 ML Depth: 4 km Intensity IV: Hilo (H). Magnitude: 3.2 ML Intensity III: Puna areas (H), Volcano (H) Intensity III: Hilo (H) Kalapana (H). Intensity!!! Parts of Puna (H), Volcano 29 January (H) Island of Hawaii (H). Origin time: 20 19 56.4 Epicenter: 19.38 N., 155.00 W. 18 January (H) Island of Hawaii Depth: 8 km Origin time: 14 49 28.3 Magnitude: 4.7 ML, 4.5 mb(G) Epicenter: 19.36 N., 155.25 W. Intensity IV Hilo (H), Puna areas (H). Depth: 10 km Mfnor nousehold breakage at unknown Magnitude: 3.6 ML location (press report). Intensity III: Hilo (H), Volcano (H) Intensity III: Kau (H), Volcano (H). Intensity II: Puna (H). Intensity II: Kona (H), northern parts of the Island. 19 January (H) Island of Hawaii Origin time: 00 13 37.8 1 February (H) Island of Hawaii Epicenter: 19.36 N., 155.13 W. Origin time: 06 07 26.9 Depth: 8 km Epicenter: 19.37 N., 155.08 W, Magnitude: 3.6 ML Depth: 8 km Intensity II; Hawaii National Park (H). Magnitude: 3.3 ML Intensity III; Hilo (H). 19 January (H) Island of Hawaii Intensity II: Glenwood (H). Origin time: 09 57 46.4 Epicenter: 19.38 N., 155.10 W. 4 February (H) Island of Hawaii Depth: 8 km Origin time: 02 42 13.4 Magnitude: 3.5 ML Epicenter: 19.38 N., 155.10 W. Intensity II: Hawaii National Park (H), Depth: 8 km Volcano (H). Magnitude: 3.4 ML Intensity III: Glenwood (H). 21 January (H) Island of Hawaii intensity II: Volcano (H). Origin time: 21 41 21.2 Epicenter: 19.37 N., 155.12 W. 4 February (H) Island of Hawaii Depth: 9 km Origin time: 06 50 58.3 Magnitude: 4.1 ML Epicenter: 19.36 N., 155.25 W.

30 Hawaii Continued Hawaii Continued

Depth: 10 km Depth: 9 km Magnitude: 3.5 ML Magnitude: 4.2 ML Intensity III; Hllo (H), Volcano (H). Intensity III: Mountainview (H), Volcano IntensltyTIT Glenwood (H), Keaau (H), (H). Kurtistown (H), Mountalnvlew (H). 25 February (H) Island of Hawaii 8 February (H) Island of Hawaii Origin time: 23 48 20.3 Origin time: 08 48 12.2 Epicenter: 19.37 N., 155.11 W. Epicenter: 19.33 N., 155.13 W. Depth: 9 km Depth: 8 km Magnitude: 3.9 ML Magnitude: 3.2 ML Intensity III: Hilo (H). Intensity III; Volcano (H). IntensitynT Pahoa (H), Volcano (H). 12 February (H) Island of Hawaii Origin time: 16 18 26.2 3 March (H) Island of Hawaii Epicenter: 19.36 N., 155.06 W. Origin time: 16 52 01.2 Depth: 8 km Epicenter: 19.40 N., 155.26 W. Magnitude: 3.2 ML Depth: 5 km Intensity II; Hilo (H). Magnitude: 2.5 ML Intensity II: Hawaii National Park (H), 13 February (H) Island of Hawaii volcano (H). Origin time: 10 49 51.8 Epicenter: 19.52 N., 155.96 W. 3 March (H) Island of Hawaii Depth: 10 km Origin time: 23 06 10.3 Magnitude: 3.6 ML Epicenter: 19.43 N., 155.28 W. Intensity III: Captain Cook (H), Holualoa Depth: 1 km (H), Kealakekua (H). Magnitude: 2.2 ML Intensity II: Hawaii National Park (H), 13 February (H) Island of Hawaii Volcano (H). Origin time: 17 12 29.1 Epicenter: 19.37 N., 155.84 W. Depth: 7 km 5 March (H) Island of Hawaii Magnitude: 2.9 ML Origin time: 13 16 52.4 Intensity II: Hilo (H). Epicenter: 19.61 N., 155.13 W. Depth: 11 km 19 February (H) Island of Hawaii Magnitude: 2.6 ML Origin time: 04 40 52.5 Intensity II: Glenwood (H), Hilo (H). Epicenter: 19.43 N., 155.28 W. Depth: 1 km 6 March (H) Island of Hawaii Magnitude: 2.8 ML Origin time: 22 23 04.6 Intensity III: Hawaii National Park (H), Epicenter: 19.36 N., 155.03 W. Intensity II: Hilo (H), Volcano (H). Depth: 7 km Magnitude: 3.5 ML 21 February (G) Island of Hawaii Intensity III; Wahaula Visitors Center (H), Origin time: 05 51 13.8 Epicenter: 20.21 N., 156.27 W. 8 March (H) Island of Hawaii Depth: 33 km Origin time: 02 25 34.6 Magnitude: 4.9 mb, 4.0 MS, 5.1 ML (H) Epicenter: 19.36 N., 155.12 U, Intensity VI: Kawaihae (wall damage Depth: 8 km amounting to $50 in one house on Hawaii Magnitude: 3.7 ML Island; minor damage to items that fell Intensity III; Volcano (H). from shelves press report). Intensity V: Hana (on Maul Island press 16 March (H) Island of Hawaii report), Hoolehua, Kahului, Kamuela, Origin time: 16 48 16.9 Kapaau, Kealakekua, Paauhau. Epicenter: 19.37 N., 155.12 W. Intensity IV: Captain Cook, Holualoa, Depth: 8 km Honokaa, Honolulu, Honomu, Kohala (H), Magnitude: 2.8 ML Kualapuu, Lanai City, Makawao, Maunaloa, Intensity II: Volcano (H). Paia, Papaikou, Volcano, Wheeler AFB. Intensity III: Kaaawa, southern parts of 19 March (H) Island of Hawaii Hawaii Island (H). Origin time: 13 04 01.3 Intensity II; Kaneohe, Ookala. Felt Epicenter: 19.41 N., 155.26 W. Islandwide: Maui (H), Oahu (H). Depth: 4 km Magnitude: 2.7 ML 24 February (H) Island of Hawaii Origin time: 15 15 19.1 Intensity III: Hawaii National Park (H), Epicenter: 19.37 N., 155.11 W. Intensity II: Volcano (H).

31 Hawaii Continued Hawaii--Continued

19 March (H) Island of Hawaii 29 March (H) Island of Hawaii Origin time: 23 24 30.3 Origin time: 18 31 29.8 Epicenter: 19.36 N., 155.06 W. Epicenter: 19.40 N., 155.26 W, Depth: 8 km Depth: 14 km Magnitude: 3.9 ML Magnitude: 3.0 ML Intensity III; H1lo (H). Intensity II Volcano (H). intensltyTTT Volcano (H). 31 March (H) Island of Hawaii 20 March (H) Island of Hawaii Origin time: 00 52 10.2 Origin time: 23 13 19.8 Epicenter: 19.34 N., 155.12 W, Epicenter: 19.33 N., 155.11 W, Depth: 9 km Depth: 9 km Magnitude: 3.4 ML Magnitude: 3.1 ML Intensity III: Hilo (H). Intensity II: H1lo (H). 2 April (H) Island of Hawaii 21 March (H) Island of Hawaii Origin time: 18 14 06.4 Origin time: 23 58 00.2 Epicenter: 19.35 N., 155.11 W. Epicenter: 19.35 N., 155.19 W, Depth: 9 km Depth: 7 km Magnitude: 4.5 mb(G), 4.6 ML Magnitude: 2.6 ML Intensity II Volcano (H). Figure 12 shows the intensity distribution on Hawaii Island. 22 March (H) Island of Hawaii Origin time: 17 27 41.6 Intensity V; Holualoa, Honomu, Epicenter: 19.29 N., 155.36 W, Mountainview, Ookala, Papaaloa, Wheeler Depth: 9 km AFB. Magnitude: 2.4 ML Intensity IV: Captain Cook, Hawaii National Intensity II: Waikeauka (H). Park, Hilo, Keaau, Kurtistown, Pahoa, Papalkou, Puna district (H), Volcano. 23 March (H) Island of Hawaii Intensity III: Kau district (H). Origin time: 06 48 26.9 Intensity II; Hakalau, Kamuela (H), Kona Epicenter: 19.37 N., 155.09 W, district (H). Depth: 8 km Magnitude: 3.3 ML Intensity III; H1lo (H).

23 March (H) Island of Hawaii EXPLANATION Origin time: 07 19 56.6 picenter Epicenter: 19.34 N., 155.11 W, Depth: 9 km 5 Felt at intensity 5 Magnitude: 3.1 ML " Not Felt Intensity II: H1lo (H). 24 March (H) Island of Hawaii Origin time: 00 38 11.1 Epicenter: 19.33 N., 155.19 W. Depth: 8 km Magnitude: 2.8 Intensity II Volcano (H). 24 March (H) Island of Hawaii Origin time: 01 06 03.1 Epicenter: 19.32 N., 155.31 W. Depth: 9 km Magnitude: 3.7 ML Intensity III: Kona (H). 19 Intensi Hawaii National Park (H), H1IO (H). Figure 12. Area affected by Hawaii earthquake of April 2 29 March (H) Island of Hawaii Origin time: 15 09 51.9 2 April (H) Island of Hawaii Epicenter: 19.37 N., 155.25 W. Origin time: 19 14 11.9 Depth: 10 km Epicenter: 19.62 N., 155.99 W. Magnitude: 3.7 ML Depth: 10 km Intensity III: Hilo (H). Magnitude: 3.4 ML Intensity II; Hawaii National Park (H), Intensity III: Captain Cook (H), Kealakekua Keaau (H), Volcano (H). (H). 32 Hawaii--Continued Hawaii Continued

2 April (H) Island of Hawaii Depth: 9 km Origin time: 19 55 03.3 Magnitude: 4.2 ML Epicenter: 19.34 N., 155.22 W. Intensity III: Hilo (H), Kalapana (H). Depth: 8 km Intensity II: Hawaiian Volcano Observatory Magnitude: 3.6 ML (H), Keaau (H), Mountainview (H). Intensity III: Hilo (H). Intensity II: Volcano (H). 27 April (H) Island of Hawaii Origin time: 07 44 41.6 3 April (H) Island of Hawaii Epicenter: 19.39 N., 155.28 W. Origin time: 11 43 42.2 Depth: 6 km Epicenter: 19.40 N., 155.28 W. Magnitude: 3.2 ML Depth: 4 km Intensity III: Hawaii National Park (H). Magnitude: 3.0 ML IntensityTIT Volcano (H). Intensity III: Hawaii National Park (H), IntensityTIT Volcano (H). 27 April (H) Island of Hawaii 11 April (H) Island of Hawaii Origin time: 23 40 12.1 Origin time: 15 48 21.4 Epicenter: 19.41 N., 155.26 W. Epicenter: 19.41 N., 155.21 W. Depth: 2 km Depth: 2 km Magnitude: 2.6 ML Magnitude: 2.3 ML Intensity II Hawaii National Park (H). Intensity HI: Hawaii National Park (H) Intensity II: Volcano (H). 6. May (H) Island of Hawaii Origin time: 04 32 20.3 12 April (H) Island of Hawaii Epicenter: 19.40 N., 155.27 W. Origin time: 01 35 49.2 Depth: 2 km - Epicenter: 19.35 N., 155.06 W. Magnitude: 2.2 ML Depth: 6 km Intensity II: Hawaii National Park (H). Magnitude: 3.4 ML Intensity II; Mountainview (H), Volcano (H), 9 May (H) Island of Hawaii Origin time: 16 14 43.3 15 April (H) Island of Hawaii Epicenter: 19.36 N., 155.13 W. Origin time: 08 01 36.0 Depth: 10 km Epicenter: 19.46 N., 154.89 W. Magnitude: 3.4 ML Depth: 9 km Intensity II; Glenwood (H), Volcano (H). Magnitude: 3.3 ML Intensity III; Pahoa (H). 12 May (H) Island of Hawaii IntensityTIT Kapoho (H). Origin time: 15 55 11.4 Epicenter: 19.34 N., 155.19 W. 20 April (H) Island of Hawaii Depth: 10 km Origin time: 17 11 03.0 Magnitude: 3.7 ML Epicenter: 19.36 N., 155.25 W, Intensity III: Hilo. Depth: 9 km Intensity II; Captain Cook (H), Glenwood Magnitude: 3.5 ML (H), Papaikou (H), Volcano (H). Intensity II; Hilo (H). 22 April (H) Island of Hawaii 16 May (H) Island of Hawaii Origin time: 04 13 34.5 Origin time: 07 39 58.5 Epicenter: 18.80 N., 155.00 W. Epicenter: 19.43 N., 155.28 W. Depth: 49 km Depth: 5 km Magnitude: 4.6 ML Magnitude: 2.7 ML Intensity III: Hainakea, Hilo (H), Papaikou Intensity III; Hawaii National Park (H). (H), Puna and South Kona areas (press Intensity TIT Volcano (H). report). Intensity II; Glenwood (H), Oceanview Estate 17 May (H) Island of Hawaii (H), Volcano (H). Origin time: 11 45 06.0 Epicenter: 19.33 N., 155.27 W, 22 April (H) Island of Hawaii Depth: 10 km Origin time: 15 54 04.8 Magnitude: 3.6 ML Epicenter: 19.53 N., 155.31 W. Intensity III: Hilo (H). Depth: 12 km Magnitude: 3.4 ML 18 May (H) Island of Hawaii Intensity II Glenwood (H), Volcano (H). Origin time: 06 54 49.1 Epicenter: 19.33 N., 155.14 W, 23 April (H) Island of Hawaii Depth: 9 km Origin time: 22 29 53.7 Magnitude: 3.0 ML Epicenter: 19.37 N., 155.09 W. Intensity II; Volcano (H). 33 Hawaii--Continued Hawaii Continued

18 May (H) Island of Hawaii Intensity III: Honokaa (H), Kohala (H), Origin time: 16 16 41.2 Waimea (H). Epicenter: 19.33 N., 155.13 W. Intensity II: Hilo (H). Depth: 9 km Magnitude: 3.5 ML 31 May (H) Island of Hawaii Intensity III; Hilo (H). Origin time: 18 32 18.8 Intensity II: Mountainview (H), Volcano (H) Epicenter: 19.52 N., 156.24 W. Depth: 17 km Magnitude: 4.5 ML 20 May (H) Island of Hawaii Intensity IV: Kona. Origin time: 03 12 05.4 Intensity III Honokaa (H), Kamuela (H), Epicenter: 19.33 N., 155.13 W, Kohala (H). Depth: 9 km Intensity II: Pepeekeo (H). Magnitude: 3.8 ML Intensity III: Volcano (H). 31 May (H) Island of Hawaii Intensity II: Kahuku Ranch (H). Origin time: 18 32 24.9 Epicenter: 19.55 N., 155.59 W. Depth: 2 km 22 May (H) Island of Hawaii Magnitude: 3.7 ML Origin time: 05 53 09.7 Intensity III: Honokaa (H), Kamuela (H), Epicenter: 19.35 N., 155.10 W. Kohala (H). Depth: 9 km Intensity II: Pepeekeo (H). Magnitude: 3.2 ML Intensity II Hilo (H). 1 June (H) Island of Hawaii Origin time: 20 02 22.0 23 May (H) Island of Hawaii Epicenter: 19.36 N., 155.20 W. Origin time: 04 52 08.3 Depth: 1 km Epicenter: 19.36 N., 155.25 W, Magnitude: 2.7 ML Depth: 11 km Intensity II: Hilo (H). Magnitude: 3.7 ML Intensity III: Hilo (H). 5 June (H) Island of Hawaii Intensity II: Volcano (H). Origin time: 08 50 51.2 Epicenter: 19.36 N., 155.12 W. 24 May (H) Island of Hawaii Depth: 9 km Origin time: 03 31 20.1 Magnitude: 4.1 ML Epicenter: 19.34 N., 155.12 W. Intensity III Hilo (H), Kalapana (H), Depth: 9 km Volcano (H), Magnitude: 4.0 ML Intensity II: Glenwood (H), Keaau (H), Intensity III: Hilo (H). Papaikou (H). Intensity II: Captain Cook (H), Volcano (H), 9 June (H) Island of Hawaii Origin time: 21 03 42.6 24 May (H) Island of Maui Epicenter: 19.22 N., 155.46 W. Origin time: 09 24 08.2 Depth: 10 km Epicenter: 20.80 N., 156.24 W. Magnitude: 2.7 ML Depth: 0 km Intensity II: Pahala. Magnitude: 4.1 ML Intensity V: Wailuku, Maui. 15 June (H) Island of Hawaii Intensity IV: Kualapuu Molokai; Lanai City, Origin time: 00 17 15.2 Lanai; Makawao, Maui. Epicenter: 19.41 N., 155.26 W. Intensity III: Honolulu, Oahu; Kohala, Hawaii Depth: 4 km (press report); Kula, Maui (press report); Magnitude: 3.2 ML Lahaina, Maui (press report); Pukalani, Intensity II: Hawaiian Volcano Observatory Maui (press report). (H). Intensity II; Kona, Hawaii (H). 15 June (H) Island of Hawaii 24 May (H) Island of Hawaii Origin time: 15 00 32.4 Origin time: 09 24 20.5 Epicenter: 19.46 N., 155.48 W. Epicenter: 20.06 N., 155.80 W. Depth: 10 km Depth: 6 km Magnitude: 3.4 ML Magnitude: 3.6 ML Intensity II: Volcano (H). Intensity III: Maui (H). 16 June (H) Island of Hawaii 31 May (H) Island of Hawaii Origin time: 19 17 15.8 Origin time: 16 27 23.3 Epicenter: 19.36 N., 155.08 W. Epicenter: 20.12 N., 155.76 W. Depth: 8 km Depth: 29 km Magnitude: 3.4 ML Magnitude: 3.5 ML Intensity II Hilo (H), Papaikou (H).

34 Hawai i Conti nued Hawaii Continued

18 June (H) Island of Hawaii 25 June (H) Island of Hawaii Origin time: 22 01 11.6 Origin time: 11 29 52.5 Epicenter: 19.38 N., 155.10 W. Epicenter: 19.39 N., 155.28 W. Depth: 8 km Depth: 4 km Magnitude: 3.4 ML Magnitude: 2.5 ML Intensity II: Hilo (H). Intensity II: Volcano (H).

20 June (H) Island of Hawaii July (H) Island of Hawaii Origin time: 10 25 11.3 Origin time: 15 57 37.8 Epicenter: 19.39 N., 155.25 W. Epicenter: 19.26 N., 155.53 W. Depth: 5 km Depth: 9 km Magnitude: 3.1 ML Magnitude: 2.6 ML Intensity III: Hawaii National Park (H), Intensity II Pahala. IntensitylTT Volcano (H). 8 July (H) Island of Hawaii Origin time: 03 49 06.6 20 June (H) Island of Hawaii Epicenter: 19.40 N., 155.26 W. Origin time: 13 06 23.7 Depth: 5 km Epicenter: 19.19 N., 155.55 W. Magnitude; 2.5 ML Depth: 10 km Intensity II Hawaii National Park, Magnitude: 3.1 ML Intensity III: Pahala (H). 8 July (H) Island of Hawaii Intensity II: Captain Cook (H). Origin time: 07 39 17 Epicenter: 19.39 N., 155.26 W. Depth: 7 km 22 June (H) Island of Hawaii Magnitude: 2.7 ML Origin time: 00 27 49.5 Intensity III: Hawaii National Park, Epicenter: 19.37 N., 155.22 W. Intensity II: Volcano. Depth: 9 km Magnitude: 2.6 ML Intensity II Volcano (H). 12 July (H) Island of Hawaii Origin time: 09 26 10.7 19.35 N., 155.22 W. 22 June (H) Island of Hawaii Epicenter: Origin time: 04 16 27.2 Depth: 10 km Epicenter: 19.37 N., 155.22 W, Magnitude: 3.2 ML Depth: 6 km Intensity II: Volcano. Magnitude: 3.1 ML Intensity III: Volcano (H). 12 July (H) Island of Hawaii Origin time: 22 45 35.2 22 June (H) Island of Hawaii Epicenter: 19.38 N., 155.25 W. Origin time: 06 00 34.7 Depth: 5 km Epicenter: 19.37 N., 155.22 W. Magnitude: 3.0 ML Depth: 6 km Intensity II: Hawaiian Volcano Observatory, Magnitude: 3.3 ML Intensity III: Volcano (H). 14 July (H) Island of Hawaii Origin time: 12 05 02.3 22 June (H) Island of Hawaii Epicenter: 19.39 N., 155.24 W. Origin time: 07 27 28.9 Depth: 6 km Epicenter: 19.39 N., 155.25 W. Magnitude: 3.3 ML Depth: 2 km Intensity III: Hawaii National Park. Magnitude: 3.0 ML Intensity II; Volcano. Intensity II: Volcano (H).

22 June (H) Island of Hawaii 15 July (H) Island of Hawaii Origin time: 13 04 39.6 Origin time: 00 14 38. Epicenter: 19.38 N., 155.24 W, Epicenter: 19.37 N., 155.21 W. Depth: 3 km Depth: 6 km Magnitude: 3.2 ML Magnitude: 3.2 ML Intensity III Volcano (H). Intensity II: Volcano. 25 June (H) Island of Hawaii Origin time: 05 47 53.7 15 July (H) Island of Hawaii Epicenter: 19.34 N., 155.20 W, Origin time: 18 54 39.8 Depth: 9 km Epicenter: 19.36 N., 155.13 W. Magnitude: 3.6 ML Depth: 8 km Intensity III: Hilo (H). Magnitude: 3.3 ML Intensity II: Volcano (H). Intensity II: Hilo.

35 Hawaii Continued Hawaii Continued

16 July (H) Island of Hawaii Magnitude: 3.8 ML Origin time: 11 11 28. 6 Intensity III: Hilo. Epicenter: 19.19 N., 155.55 W. Intensity II: Keaau, Mountain View. Depth: 10 km Magnitude: 3.2 ML 30 July (H) Island of Hawaii Intensity II: Pahala. Origin time: 18 02 34.9 Epicenter: 19.34 N., 155.12 W, 22 July (H) Island of Hawaii Depth: 9 km Origin time: 12 40 53. 0 Magnitude: 2.7 ML Epicenter: 19.38 N., 155.08 W. Intensity II Hilo. Depth: 9 km 31 July (H) Island of Hawaii Magnitude: 3.7 ML Origin time: 09 19 13.9 Intensity III : Hilo. Epicenter: 19.34 N., 155.20 W. intensity II: Mountain View, Papai kou Depth: 9 km Magnitude: 3.0 ML 23 July (H) Island of Hawaii Intensity II; Volcano. Origin time: 07 49 45.4 Epicenter: 19.39 N., 155.25 W. 1 August (H) Island of Hawaii Depth: 5 km Origin time: 02 51 36.0 Magnitude: 3.3 ML Epicenter: 19.41 N., 155.27 W. Intensity III; Hawaii National Park, Depth: 5 km Intensity II; Volcano. Magnitude: 3.3 ML Intensity III: Hawaii National Park, 24 July (H) Island of Hawaii Intensity II: Volcano. Origin time: 05 38 17.0 2 August (H) Island of Hawaii Epicenter: 19.34 N., 155.14 W. Origin time: 01 01 17.4 Depth: 9 km Epicenter: 19.37 N., 155.09 W. Magnitude: 3.7 ML Depth: 9 km Intensity II: Kurtistown, Naniwale, Volcano. Magnitude: 3.4 ML Intensity III: Hilo. 25 July (H) Island of Hawaii Origin time: 06 53 44.1 2 August (H) Island of Hawaii Epicenter: 19.38 N., 155.12 W. Origin time: 02 39 18.0 Depth: 9 km Epicenter: 19.39 N., 155.25 W. Magnitude: 2.9 ML Depth: 6 km Intensity II: Glenwood. Magnitude: 3.6 ML Intensity III: Hawaii National Park, 27 July (H) Island of Hawaii Origin time: 17 14 26.8 2 August (H) Island of Hawaii Epicenter: 19.37 N., 155.09 W. Origin time: 16 37 01.3 Depth: 9 km Epicenter: 19.36 N., 155.25 W. Magnitude: 4.0 ML Depth: 10 km Intensity III; Hilo. Magnitude: 3.2 ML Intensity II: Glenwood, Kurtistown, Mountain Intensity II; Hilo. View, Papalkou, Volcano. 9 August (H) Island of Hawaii 28 July (H) Island of Hawaii Origin time: 23 09 33.5 Origin time: 06 37 Epicenter: 19.39 N., 155.24 W. Epicenter: 19.39 155.24 W. Depth: 5 km Depth: 5 km Magnitude: 3.4 ML Magnitude: 3.6 ML Intensity III: Hawaii National Park. Intensity III; Hawaii National Park, Hawaiian Intensity II: Hawaiian Volcano Observatory, Volcano Observatory. Intensity II: Volcano. 11 August (H) Island of Hawaii Origin time: 05 03 47.5 30 July (H) Island of Hawaii Epicenter: 19.32 N., 155.22 W. Origin time: 08 46 35.2 Depth: 10 km Epicenter: 19.37 N., 155.25 W. Magnitude: 3.5 ML Depth: 6 km Intensity II: Hilo, Kurtistown, Volcano. Magnitude: 3.0 ML Intensity II; Hawaii National Park, Volcano. 12 August (H) Island of Hawaii Origin time: 02 30 11.0 30 July (H) Island of Hawaii Epicenter: 19.34 N., 155.19 W. Origin time: 15 09 43.6 Depth: 9 km Epicenter: 19.34 N., 155.11 W. Magnitude: 2.7 ML Depth: 8 km Intensity II: Hawaii National Park.

36 Hawaii Continued Hawaii Continued

15 August (H) Island of Hawaii 8 September (H) Island of Hawaii Origin time: 03 01 00.3 Origin time: 08 01 16.2 Epicenter: 19.36 N., 155.14 W, Epicenter: 19.37 N., 155.08 W. Depth: 9 km Depth: 8 km Magnitude: 3.2 ML Magnitude: 3.5 ML Intensity II: Volcano. Intensity III Hilo, Kurtistown. intensity n; Hawaii National Park, 18 August (H) Island of Hawaii Origin time: 03 25 34.5 8 September (H) Island of Hawaii Epicenter: 19.41 N., 155.26 W. Origin time: 14 01 55.4 Depth: 2 km Epicenter: 19.31 N., 155.35 W. Magnitude: 2.3 ML Depth: 9 km Intensity II; Volcano. Magnitude: 3.2 ML Intensity II: Glenwood, Hilo. 23 August (H) Island of Hawaii Origin time: 02 26 55.8 10 September (H) Island of Hawaii Epicenter: 19.38 N., 155.24 W. Origin time: 06 46 22.2 Depth: 5 km Epicenter: 19.39 N., 155.07 W, Magnitude: 2.2 ML Depth: 8 km Intensity II Hawaii National Park. Magnitude: 2.5 ML Intensity II: Mountain View. 26 August (H) Island of Hawaii Origin time: 13 19 43.5 11 September (H) Island of Hawaii Epicenter: 19.36 N., 155.25 W. Origin time: 15 04 30.4 Depth: 10 km Epicenter: 19.37 N. , 155.07 W, Magnitude: 3.6 ML Depth: 8 km Intensity III: Volcano. Magnitude: 3.6 ML Intensity II: Hilo, Mountain View, Papalkou, Intensity III: Hilo. Intensity II: Keaau. 31 August (H) Island of Hawaii Origin time: 20 41 08.3 12 September (H) Island of Hawaii Epicenter: 19.39 N., 155.49 W. Origin time: 23 21 43.3 Depth: 10 km Epicenter: 19.43 N., 154.97 W, Magnitude: 4.0 ML Depth: 5 km Intensity III: Hawaiian Volcano Observatory Magnitude: 2.8 ML Intensity II: Kona. Intensity II; Pahoa. 2 September (H) Island of Hawaii 21 September (H) Island of Hawaii Origin time: 20 20 26.7 Origin time: 19 35 49.7 Epicenter: 19.35 N., 155.05 W, Epicenter: 19.35 N., 155.11 W. Depth: 8 km Depth: 9 km Magnitude: 3.5 ML Magnitude: 3.2 ML Intensity III: Hilo. Intensity II; Hilo. Intensity II: Kalapana. 28 September (H) Island of Hawaii 4 September (H) Island of Hawaii Origin time: 19 14 53.3 Origin time: 08 03 41.4 Epicenter: 19.33 N., 155.22 W. Epicenter: 19.48 N., 154.86 W Depth: 10 km Depth: 9 km Magnitude: 3.7 ML Magnitude: 3.5 ML Intensity III Hawaiian Volcano Observatory, Intensity III: Pahoa. Hilo. ______Intensity II; Honaunau, Honokaa, Kapapala 4 September (H) Island of Hawaii Ranch, Mountain View, Naniwale, Papaikou, Origin time: 23 10 54.1 Pepeekeo. Epicenter: 19.33 N., 155.27 W. Depth: 10 km 29 September (H) Island of Hawaii Magnitude: 3.9 ML Origin time: 22 58 03.9 Intensity III: Hawaiian Volcano Observatory, Epicenter: 19.34 N., 155.09 W. Volcano. Depth: 9 km Intensity II: Hilo, Honaunau, Keaau, Pahoa. Magnitude: 3.3 ML Intensity III: Hilo. 6 September (H) Island of Hawaii Origin time: 15 34 15.2 4 October (H) Island of Hawaii Epicenter: 19.44 N., 154.91 W. Origin time: 15 18 52.5 Depth: 9 km Epicenter: 19.35 N., 155.11 W. Magnitude: 3.5 ML Depth: 9 km Intensity III; Glenwood. Magnitude: 3.0 ML Intensity II; Hawaii National Park, ^Intensity II: Hilo (H).

37 Hawaii Continued Hawaii Continued

5 October (H) Island of Hawaii 5 November (H) Island of Hawaii Origin time: 15 58 50.5 Origin time: 00 44 55.8 Epicenter: 19.34 N., 155.11 W. Epicenter: 19.41 N., 155.27 W. Depth: 9 km Depth: 3 km Magnitude: 3.8 ML Magnitude: 2.3 ML Intensity III: Hawaiian Beaches (H), Hilo Intensity III: Hawaii Volcanoes National Park (H). Intensity II: Mountain View (H), Papaikou Intensity II: Volcano (H). (H), Volcano (H). 5 November (H) Island of Hawaii 5 October (H) Island of Hawaii Origin time: 12 58 29.6 Origin time: 19 55 39.6 Epicenter: 19.36 N., 155.14 W. Epicenter: 19.37 N., 155.08 W. Depth: 9 km Depth: 8 km Magnitude: 2.7 ML Magnitude: 3.5 ML Intensity II: Volcano (H). Intensity III: Hilo (H), Kalapana (H). 10 November (H) Island of Hawaii Intensity TIT Volcano (H). Origin time: 01 33 03.3 9 October (H) Island of Hawaii Epicenter: 19.34 N., 155.07 W. Origin time: 02 29 29.9 Depth: 9 km Epicenter: 19.55 N., 155.85 W. Magnitude: 3.8 ML Depth: 25 km Intensity III: Hilo (H). Magnitude: 3.3 ML Intensity II; Hale Pohaku (H), Pepeekeo Intensity II: Kona district (H). (H), Wood Valley (H). 15 October (H) Island of Hawaii 11 November (H) Island of Hawaii Origin time: 09 17 06.9 Origin time: 04 15 16.5 Epicenter: 19.38 N., 155.09 W. Epicenter: 19.35 N., 155.19 W. Depth: 9 km Depth: 10 km Magnitude: 2.7 ML Magnitude: 3.1 ML Intensity II: Hamakua district (H), Hilo Intensity II: Mountain View (H). (H). 13 November (H) Island of Hawaii Origin time: 02 54 46.4 21 October (H) Island of Hawaii Epicenter: 19.35 N., 155.04 W. Origin time: 12 25 26.0 Depth: 8 km Epicenter: 19.45 N., 154.87 W. Magnitude: 3.5 ML Depth: 9 km Intensity II: Volcano (H). Magnitude: 2.9 ML Intensity II: Pahoa (H). 13 November (H) Island of Hawaii Origin time: 21 14 03.3 22 October (H) Island of Hawaii Epicenter: Origin time: 22 43 23.6 19.37 N., 155.09 W. Epicenter: 19.32 N., 155.20 W. Depth: 9 km Depth: 11 km Magnitude: 3.7 ML Magnitude: 3.4 ML Intensity III: Hilo (H). Intensity II: Hilo (H). 14 November (H) Island of Hawaii 23 October (H) Island of Hawaii Origin time: 14 19 23.0 Epicenter: 19.43 N., 155.28 W. Origin time: 00 11 25.8 Depth: 16 km Epicenter: 19.35 N., 155.06 W. Magnitude: 3.0 ML Depth: 9 km Intensity II: Volcano (H). Magnitude: 3.5 ML Intensity II: Hilo (H), Kalapana (H) 16 November (H) Island of Hawaii Origin time: 12 23 35.4 2.4 October (H) Island of Hawaii Epicenter: 19.38 N., 155.08 W. Origin time: 18 18 54.0 Depth: 9 km Epicenter: 19.37 N., 155.00 W. Magnitude: 3.6 ML Depth: 7 km Intensity III: Hilo. Magnitude: 2.5 ML Intensity II: Hawaiian Beaches (H), Intensity II; Wahaula Visitors Center (H), Paauhau (H). 3 November (H) Island of Hawaii 17 November (H) Island of Hawaii Origin time: 04 15 46.3 Origin time: 05 44 33.9 Epicenter: 19.32 N., 155.22 W. Epicenter: 19.43 N., 155.28 W. Depth: 10 km Depth: 1 km Magnitude: 3.7 ML Magnitude: 2.3 ML Intensity III: Mountain View (H). Intensity II: Hawaii Volcanoes National IntensityTTT Hilo (H), Volcano (H). Park (H), Volcano (H). 38 Hawaii "Continued Hawaii Continued

17 November (H) Island of Hawaii 26 November (H) Island of Hawaii Origin time: 15 51 48.5 Origin-crme: 13 49 14.8 Epicenter: 19.54 N., 155.24 W. Epicenter: 19.40 N., 155.27 W. Depth: 25 km Depth: 2 km Magnitude: 3.7 ML Magnitude: 2.1 ML Intensity III: Hilo (H). Intensity II Hawaii Volcanoes National Intensity flT Hawaii Volcanoes National Park (H). Park (H), Hawaiian Volcano Observatory (H), Keaau (H), Papaikou (H), Volcano (H), Wood Valley (H). 26 November (H) Island of Hawaii Origin time: 20 15 58.5 17 November (H) Island of Hawaii Epicenter: 19.40 N., 155.27 W. Origin time: 22 13 08.6 Depth: 5 km Epicenter: 19.38 N., 155.28 W. Magnitude: 3.1 ML Depth: 3 km Intensity HI' Hawaiian Volcano Observatory Magnitude: 2.1 ML (H). Intensity II: Hawaii Volcanoes National Intensity II: Volcano (H). Park (H), Volcano (H). December (H) Island of Hawaii 18 November (H) Island of Hawaii Origin time: 03 46 09.9 Origin time: 14 33 18.1 Epicenter: 19.33 N., 155.19 W, Epicenter: 19.35 N., 155.22 W. Depth: 10 km Depth: 9 km Magnitude: 3.3 ML Magnitude: 2.3 ML Intensity III Volcano (H). Intensity II; Hawaii Volcanoes National Park (H). December (H) Island of Hawaii Origin time: 04 18 45.2 19 November (H) Island of Hawaii Epicenter: 19.32 N., 155.19 W. Origin time: 08 24 43.7 Depth: 10 km Epicenter: 19.40 N., 155.28 W. Magnitude: 3.0 ML Depth: 4 km Intensity II: Volcano (H). Magnitude: 3.0 ML Intensity III Hawaii Volcanoes National 1 December (H) Island of Hawaii Park (H). Origin time: 05 37 30.1 Intensity II: Hawaiian Volcano Observatory Epicenter: 19.33 N., 155.27 W. (H), Volcano (H). Depth: 10 km Magnitude: 2.5 ML 22 November (H) Island of Hawaii Intensity II Volcano (H). Origin time: 06 35 13.5 Epicenter: 19.37 N., 155.11 W. 4 December (H) Island of Hawaii Depth: 8 km Origin time: 13 50 50.8 Magnitude: 2.5 ML Epicenter: 19.34 N., 155.14 W. Intensity II: Puna district (H). Depth: 9 km Magnitude: 3.0 ML 23 November (H) Island of Hawaii Intensity III: Hilo (H). Origin time: 01 40 49.9 IntensityTTT Kamuela (H), Volcano (H), Epicenter: 19.39 N., 155.28 W. Depth: 3 km 6 December (H) Island of Hawaii Magnitude: 2.4 ML Origin time: 03 11 59.1 Intensity II: Hawaii Volcanoes National Epicenter: 19.39 N., 155.11 W. Park (H), Volcano (H). Depth: 8 km Magnitude: 1.9 ML 25 November (H) Island of Hawaii Intensity II: Hilo (H). Origin time: 16 37 27.4 Epicenter: 19.39 N., 155.29 W. 6 December (H) Island of Hawaii Depth: 4 km Origin time: 16 26 58.0 Magnitude: 2.3 ML Epicenter: 19.36 N., 155.13 W. Intensity II: Hawaii Volcanoes National Depth: 10 km Park (H), Volcano (H). Magnitude: 3.8 ML Intensity III: Hawaiian Beaches (H), Hilo 25 November (H) Island of Hawaii Origin time: 21 05 40.3 Intensity II: Mountain View (H), Volcano Epicenter: 19.40 N., 155.28 W. (H). Depth: 2 km Magnitude: 2.5 ML 8 December (H) Island of Hawaii Intensity II: Hawaii Volcanoes National Origin time: 09 40 22.2 Park (H). Epicenter: 19.40 N., 155.28 W. 39 Hawaii Continued Hawaii Continued

Depth: 3 km 22 December (H) Island of Hawaii Magnitude: 2.8 ML Origin time: 19 03 32.4 Intensity II; Hawaii Volcanoes National Epicenter: 19.40 N., 155.27 W. Park (H), Volcano (H). Depth: 3 km Magnitude: 2.2 ML 9 December (H) Island of Hawaii Intensityity II Hawaii Volcanoes National Origin time: 00 15 42.5 Tark THT7"Volcano (H). Epicenter: 19.34 N., 155.18 W. Depth: 9 km 25 December (H) Island of Hawaii Magnitude: 2.9 ML Intensity II: Hilo (H). Origin time: 17 01 15.4 Epicenter: 19.64 N., 156.01 W. 9 December (H) Island of Hawaii Depth: 9 km Origin time: 04 50 26.3 Magnitude: 3.3 ML Epicenter: 19.43 N., 155.28 W. Intensity III; Kailua (H), Kona district Depth: 1 km (H). Magnitude: 2.0 ML Intensity II: Holualoa (H). Intensity II: Hawaii Volcanoes National Park (H), Volcano (H). 27 December (H) Island of Hawaii Origin time: 14 15 20.6 10 December (H) Island of Hawaii Epicenter: 19.39 N., 155.25 W. Origin time: 01 28 49.9 Depth: 5 km Epicenter: 19.40 N., 155.29 W. Magnitude: 3.3 ML Depth: 3 km Intensity III: Hawaii Volcanoes National Magnitude: 3.0 ML Park (H). Intensity III; Keanakakoi (H). Intensity II; Mountain View (H). Intensity II; Hawaiian Volcano Observatory (H), Volcano (H). 27 December (H) Island of Hawaii Origin time: 16 24 27.3 12 December (H) Island of Hawaii Epicenter: 19.32 N., 155.27 W. Origin time: 09 39 36.6 Depth: 10 km Epicenter: 19.22 N., 155.47 W. Magnitude: 3.1 ML Depth: 9 km Intensity III; Hawaii Volcanoes National Magnitude: 2.8 ML Park (H). Intensity II: Kau district (H). 27 December (H) Island of Hawaii 14 December (H) Island of Hawaii Origin time: 19 19 27.0 Origin time: 03 26 42.0 Epicenter: 19.40 N., 155.25 W. Epicenter: 19.34 N., 155.13 W. Depth: 3 km Depth: 10 km Magnitude: 2.5 ML Magnitude: 3.4 ML Intensity II: Hawaii Volcanoes National Intensity II; Puna district (H), Volcano Park (H). (H). 29 December (H) Island of Hawaii 17 December (H) Island of Hawaii Origin time: 01 17 36.6 Origi n time: 13 39 14.5 Epicenter: 19.40 N., 155.28 W. Epicenter: 19.43 N., 155.28 W. Depth: 3 km Depth: 1 km Magnitude: 2.8 ML Magnitude: 2.9 ML Intensity II: Hawaii Volcanoes National Intensity II Hawaii Volcanoes National Park (H). Park (H), Volcano (H). 29 December (H) Island of Hawaii 18 December (H) Island of Hawaii Origin time: 05 37 04.8 Origin time: 14 01 00.5 Epicenter: 19.32 N., 155.20 W. Epicenter: 19.34 N., 155.12 W. Depth: 10 km Depth: 9 km Magnitude: 3.2 ML Magnitude: 4.8 ML, 5.0 mb(G) Intensity III: Hawaiian Volcano Observatory Intensity V: Hakalao, Hilo (small objects (H). fell) (H), Honokaa, Honomu (small objects Intensity II; Volcano (H). moved), Keaau, Kurtistown, Lahaina (small objects moved), Laupahoehoe, Mountain 29 December (H) Island of Hawaii View, Ookala, Paauhau, Pahala, Volcano Origin time: 13 45 37.4 (small objects moved). Epicenter: 19.39 N., 155.29 W. Intensity IV: Puna district (H). Depth: 2 km Intensity III: Kau district (H). Magnitude: 2.4 ML Intensity TIT Kamuela (H), Kohala (H), Intensity II: Hawaii Volcanoes National Kona district (H). Park (H).

40 Hawaii Continued Indiana Continued

30 December (H) Island of Hawaii Depth: 20 km Origin time: 02 44 25.6 Magnitude: 3.0 mbLg Epicenter: 19.33 N., 155.19 W. Intensity V: Stinesville. Depth: 9 km IntensityTV; Blooming ton, Ellettsville Magnitude: 2.9 ML (telephone report), Solsberry, Spencer, Intensity II: Hawaii Volcanoes National Stanford. Park (H). 30 December (H) Island of Hawaii 13 June (I) Indianapolis, Ind. Origin time: 05 26 26.9 Origin time: 18 55 18.5, 18 58 28.5 Epicenter: 19.39 N., 155.24 W. Epicenter: None computed. Depth: 5 km Depth: None computed. Magnitude: 3.0 ML Magnitude: None computed. Intensity III: Hawaii Volcanoes National Intensity II; Indianapolis (felt by a Park (H). building engineer touring a building site),

30 December (H) Island of Hawaii Origin time: 10 47 36.9 Epicenter: 18.16 N., 155.25 W. Kentucky Depth: 7 km Magnitude: 3.9 ML Intensity II: Kau district (H). 30 December (H) Island of Hawaii 19 January (G) Eastern Kentucky Origin time: 14 19 51.5 Origin time: 06 20 39.5 Epicenter: 19.33 N., 155.27 W, Epicenter: 36.88 N., 83.83 W. Depth: 10 km Depth: 5 km Magnitude: 3.0 ML Magnitude: 4.0 mb, 3.8 ML(S). Intensity II: Volcano (H). This earthquake was felt in parts of southeastern Kentucky, northeastern Idaho Tennessee, northwestern North Carolina, southwestern West Virginia, and western Virginia. 14 June (U) Eastern Idaho Origin time: 09 37 57.8 Epicenter: 42.12 N., 112.48 W. USGS canvassed an area around the epicenter Depth: 7 km within a radius of 200 km and mailed Magnitude: 3.6 ML 1,528 questionnaires. Figure 13 shows Intensity IV Malad City, St. John. the results of this canvass and of the reevaluated questionnaires obtained from 26 July (G) Western Idaho G. R. Keller, University of Kentucky, Origin time: 10 45 28.2 Lexington (Y), who made an onsite survey. Epicenter: 45.02 N., 114.18 W. Depth: 10 km Magnitude: 4.3 mb, 4.4 ML Intensity V: Cobalt, North Fork, Tendoy. Intensity;y VI:vi: Intensity IV: Carmen, Ellis, Salmon, Shoup, KentuckyEy^M- Minor damage reported in Knox Williams Lake (press report). and Bell Counties (press report). Artemus (windows broken), Barbourville 1 November (G) Western Idaho (plaster cracked at Union College; Origin time: 22 22 51.1 objects were knocked from shelves and Epicenter: 44.26 N., 114.97 W. walls. Furniture moved. Loud earth Depth: 5 km noises Y), Bimble (fence fell on Magnitude: 3.7 ML(A), 3.9 ML(D) railroad tracks telephone report), Intensity IV: Stanley. Flat Lick (window cracked; objects IntensityTTl; Salmon, Stanley (5 km south overturned. Loud noises Y), Green of, at U.S. Forest Station). Road (concrete sidewalk cracked), Himyar, Hinkle (plaster and dry wall cracked), Jenson, Julip, Kettle Island Indiana (plaster cracked), Lexington (at Eastover Mine rocks fell on tracks, material from ceiling fell press 8 April (G) Central Indiana report), Pineville (walls cracked), Origin time: 07 38 53.0 Trosper, Walker (cracks in brick school Epicenter: 39.35 N., 86.68 W. building), Woodbine (plaster cracked). 41 Kentucky Conti nued Kentucky--Continued

36

. °NORTH EXPLANATION I Epicenter ' 4 CAROLINA 6 Felt at intensity 6 0 50km « Not felt

Figure 13 --Area affected by eastern Kentucky earthquake of January 19 Intensity V: Tennessee Clairfield, Gatlinburg, Kentucky Bryants Store, Bypro, Call away, Jacksboro, Knoxville, Kodak, Maryville, Calvin, Cannon, Corbin, Crane Nest, Oneida, Speedwell, Tallassee. Cubage, Emlyn, Four Mile, Frakes, West Virginia Gary (V). Gausdale, Girdler, Gray, Hulen, Ingram, Intensity III: Jeffersonville, Li da, London, Marydell, Kentucky Chenoa, Dana, Faubush, Field, Nevisdale, Pine Knot, Pulaski, Revelo, Harlan (Y), Hyden (Y), Middlesboro Salt Gum, Sasser, Scalf, Siler, (press report). Sizerock, Somerset (press report), North Carolina Almond. Steubenville, Strunk, Tinsley, West Tennessee Lafayette. Liberty, Williamsburg (press report). North Carolina Tuckasegee. Intensity II: Tennessee Andersonville (press report), Kentucky Ashland (Y), Cumberland (press Duff, Eagan, Jellico, Johnson City report), Molus (press report), Paint (press report), La Follette (dishes Lick, Summersville. were knocked from cabinets; tires fell North Carolina Arden. on floor in auto store press report), West Virginia Switier. Midway, Shawanee, Tri-County Airport (press^ report ),_Yonoret Wall and. 15 April (G) Western Kentucky Vi rgi ni a--Ewi ng, Rose Hii 11. Origin time: 07 03 34.9 West Virginia Naugatuck. Epicenter: 37.41 N., 87.31 W. Intensity;y IV: Depth: 15 km Kentucky:lcy Arjay,Arj< Baileys Switch, Beauty, Magnitude: 3.3 mbLg(V) Bush, Buskirk, Dice, Garrard, Hazel Intensity V; Allegre, Calhoun, Crofton, Green (press report), Hector, Keavy, Curdsville, Manitou. Kona, Loyal 1, Manchester, Mount Intensity IV: Elkton, Fairview, Steff. Sterling, Napfor, Pointer, River, Ruth, Intensity III Hopkinsville (telephone Sitka, Tedders, Tuttle, Walden, report), Island (telephone report), Wendover, Wittensville. Liver-more (telephone report), Rochester. North Carolina Alexander, Montreat. Intensity II: Waverly. 42 Maine Massachusetts Conti nued

15 April (J) Southwestern Maine Intensity V: Harwich, North Chatham, West Origin time: 10 36 04.8 Dennis, West Harwich. Epicenter: 44.24 N., 70.14 W. Intensity IV: Brewster, Chatham (press Depth: 0 km report), Dennis, Dennis Port, Harwich Magnitude: 2.4 mbLg Port, Sandwich (press report), South Intensity III: Auburn, Green. Chatham, South Dennis, South Orleans, Intensity II: Turner. Yarmouth. Intensity III; West Yarmouth. 23 October (0) Southern Quebec, Canada Intensity II: East Dennis, Sagamore Beach. Origin time: 20 58 18.0 Epicenter: 47.82 N., 69.79 W. 10 May (C) Southeastern Massachusetts Depth: 18 km Origin time: 01 34 20.5 Magnitude: 3.8 mb(G), 4.2 mbLg, Epicenter: 41.54 N., 71.01 W. 4.1 mbLg(L), 3.8 mbLg(J) Depth: 0 km Magnitude: 2.7 mbLg This earthquake was felt over a large area Intensity V: of southern Quebec, Canada, as shown by Massachusetts Mattapoisett, South figure 14 (furnished by R. Wetmiller, Dartmouth, Westport. Earth Physics Branch, Energy, Mines, and Intensity IV: Resources, Ottawa, Canada). All the Massachusetts Fai rhaven. North Dartmouth, intensity values shown in figure 14 were Westport Point. evaluated by the office of R. Wetmiller. Rhode Island Providence. Intensity III: Intensity IV: Massachusetts Dartmouth, New Bedford. Maine Fort Kent, Frenchville. Rhode Island Little Compton. New Brunswick--(press report). Intensity II: Massachusetts Fall River.

Michigan

2 February (0) Southern Ontario, Canada Origin time: 21 14 02.0 Epicenter: 41.96 N., 82.67 W. Depth: 10 km .. "K. xA43J-3 Magnitude: 3.4 ML \ m / /E ¥3.43.4 /' 2 3 Intensity IV (from press reports): \ ST SIMEON tf-^ Michigan Flat Rock, Rockwood, Trenton. *i ^^* x.^ ^3i ».:s 2 5 Intensity III (from press reports): Michigan New Boston, Gibraltar, Grosse He. Ontario, Canada Colchester, Leamington.

Mi ssouri

23 January (S) New Madrid, Mo Origin time: 00 56 39.6 Figure 14.--Area affected by southern Quebec, Epicenter: 36.55 N., 89.60 W Canada, earthquake of October 23 Depth: 9 km Magnitude: 2.0 ML Intensity IV: Marston. Massachusetts 22 May (S) New Madrid Region Origin time: 07 40 46.0 Epicenter: 36.04 N., 89.84 W. 14 March (C) Cape Cod, Mass. Depth: 10 km Origin time: 23 12 24.6 Magnitude: 3.2 mbLg Epicenter: 41.66 N., 69.97 W. Intensity V: Depth: 0 km Missouri Cooter, Steele. Magnitude: 3.0 ML(L) Tennessee El 1 endal e. 43 Missouri Continued Montana Conti nued

13 December (S) Eastern Missouri 8 December (G) Hebgen Lake region Origin time: 08 35 54.9 Origin time: 22 10 42.3 Epicenter: 37.80 N., 90.24 W. Epicenter: 44.75 N., 111.05 W. Depth: 5 km Depth: 5 km Magnitude: 3.5 mbLg Magnitude: 3.5 ML Intensity V: Intensity III; Gardiner, West Yellowstone Mi ssouri Cl earwater, Farmington (8 km north of), Flat River, Frankclay, Ironton, Perryville. 20 December (G) Hebgen Lake region Intensity IV: Origin time: 17 07 10.5 Missouri Arcadia, Belleview, Iron Epicenter: 44.50 N., 111.07 W. Mountain. Depth: 9 km Illinois Renault, Welge. Magnitude: 3.3 ML(A) The intensity data below were furnished by R. A. Hutchinson, National Park Service Montana geologist, Yellowstone National Park, Wyo, Intensity III; 21 January (G) Northwestern Montana Wyoming Canyon Village, Madison Origin time: 13 43 29.6 Junction, Mammoth Hot Springs. Epicenter: 48.22 N., 114.10 W. Intensity II; Depth: 5 km Montana Gardiner, West Yellowstone. Magnitude: 3.1 ML Wyoming Old Faithful. Intensity IV; Creston, Hungry Horse, Somers. Intensity III; Flathead Lake region (press report). Nevada 13 February (G) Western Montana Origin time: 06 13 43.1 Epicenter: 46.75 N., 112.13 W. Depth: 1 km 8 February (G) Northwestern Nevada Magnitude: 3.8 ML Origin time: 06 09 26.5 Intensity IV; Clancy, East Helena, Epicenter: 39.47 N., 119.76 W. Marysville. Depth: 5 km Intensity II: Helena. Magnitude: 3.4 ML (B) Intensity IV: Virginia City. 5 April (G) Western Montana Intensity III Reno. Origin time: 02 40 07.4 Intensity"!!? Pleasant Valley, Steamboat Epicenter: 46.13 N., 111.68 W. (telephone "report). Depth: 5 km Magnitude: 3.6 ML(D) Intensity IV Trident. 10 June (G) Central Nevada Origin time: 10 39 35.9 24 April (G) Western Montana Epicenter: 39.63 N., 115.85 W. Origin time: 08 49 12.0 Depth: 2 km Epicenter: 48.26 N., 114.09 W. Magnitude: None computed. Depth: 5 km Intensity V: Eureka. Magnitude: 2.9 ML Intensity'II; Kalispell area (tel. report). 24 Ju "e .(?) Western Nevada Origin time: 00 24 45.1 Epicenter: 39.45 N., 119.53 W. 28 July (G) Western Montana Depth: 2 km Origin time: 05 06 16.9 Magnitude: 3.5 ML(B) Epicenter: 47.55 N., 112.73 W. Intensity V: Reno. Depth: 5 km Intensity IV; Silver City, Stateline. Magnitude: 3.5 ML(D), 3.5 ML 29 June (G) Western Nevada Intensity IV Augusta. Origin time: 13 10 48.8 Epicenter: 39.45 N., 119.54 W. 27 November (G) Hebgen Lake region Depth: 6 km Origin time: 00 24 46.1 Magnitude: 3.5 ML(B) Epicenter: 44.64 N., 111.14 W. Intensity V: Depth: 9 km Nevada--Reno. Magnitude: 3.3 ML(A), 3.7 ML(D) Intensity IV: Intensity IV: California Frazier Park, Calif, (observer Wyoming Canyon Village, Madison reported event at 18:20 UTC; probably is Junction. a different earthquake). 44 Nevada Continued New Jersey Continued

2 August (G) California-Nevada border region The Lamont-Doherty Geological Observatory Origin time: 08 14 07.4 (LOGO, Columbia University, Palisades, Epicenter: 38.38 N., 118.19 W. N.Y.) placed an earthquake questionnaire Depth: 8 km form in several community newspapers in the Magnitude: 4.8 mb, 4.3 ML(B) area. The completed forms received by LOGO Intensity IV: Luning, Mina. were forwarded to USGS and reevaluated. Intensity II: Hawthorne. There was one report of cracked and fallen plaster (VI); there were five reports 14 August (G) Western Nevada stating that small objects moved, chinaware Origin time: 07 50 44.9 fell, and pictures were knocked askew; some Epicenter: 39.48 N., 119.62 W. were frightened, especially children and Depth: 7 km animals (V). Magnitude: 2.2 ML The results of the combined canvass are as Intensity II: Steamboat (R). follows: 14 August (G) Western Nevada Intensity VI: Pompton Lakes (reports of Origin time: 07 58 32.4 ceiling cracks extending from fireplace to Epicenter: 39.45 N., 119.54 W, center of room, with small pieces of Depth: 4 km plaster found on rug; pictures Magnitude: 3.1 ML(B) dislodged confirmed by LOGO personnel), Intensity II Steamboat (R). Kinnelon (cracked plaster and windows press report), Ridgefield (ceiling 14 August (G) Western Nevada cracked). Origin time: 08 08 03.1 Epicenter: 39.43 N., 119.64 W, Intensity V; Belleville, Bogota, Butler, Depth: 6 km Cliffside Park, Cresskill, East Rutherford, Magnitude: 2.2 ML Englewood Cliffs, Fairview, Fort Lee, Intensity II; Steamboat (R). Garfield, Hackensack, Lyndhurst, Moonache, New Mil ford, North Bergen, Nuttley, 4 October (G) Southern Nevada Palisades Park, Ridgefield Park, River Origin time: 14 48 39.0 Edge, Rutherford, Smoke Rise, Wellington, Epicenter: 36.03 N., 114.74 W. West Mil ford (Shady Lake and High Crest Depth: 5 km subdivisions of West Mil ford). Magnitude: 3.0 ML Intensity IV: Alpine, Bloomingdale, Intensity III: Hoover Dam. Demerest, Dumont, Edgewater, Englewood, Hasbrouch Heights, Leonia, Little Ferry, 19 October (G) Southern Nevada Lodi, Maywood, Montville, Newfoundland, Origin time: 01 59 10.6 North Arlington, Paramus, Rochelle Park, Epicenter: 35.98 N., 114.82 W. Secaucus, Teaneck, Tenafly, Totowa Boro, Depth: 5 km Union City, Weehawken, West New York, Wood Magnitude: None computed. Ridge. Intensity III: Boulder City (press report), Intensity III: Bergenfield, Elmwood Park, Glen Ridge, Guttenberg, Haworth, Jersey 17 November (G) Northern Nevada City, Kearny, Lake Edenwold, Midvale, Origin time: 08 23 35.0 Riverdale, South Orange, Upper Montclair, Epicenter: 40.54 N., 115.99 W. Upper Saddle River, Wayne, Westwood. Depth: 15 km Intensity II: Ringwood. Magnitude: 3.9 ML(B) Intensity IV; Elko, Tuscarora. 13 April (L) Northeastern New Jersey Origin time: 15 39 13.2 Epicenter: 40.84 N., 74.05 W. New Jersey Depth: 2 km Magnitude: 3.1 mbLg

11 March (L) Northeastern New Jersey This canvass was conducted by Lamont-Doherty Origin time: 21 07 20.4 Geological Observatory (Columbia Epicenter: 40.96 N., 74.37 W. University, Palisades, N.Y.) by means of a Depth: 4 km questionnaire in local northern New Jersey Magnitude: 2.4 mbLg papers. Results of the canvass, consisting of letters and questionnaires, were Residents in Morris and Passaic Counties, reevaluated by the USGS. along with those in a few towns in Bergen County in northern New Jersey, felt this The press reported that 200,000 people live earthquake. Slight damage occurred at in the 50 sq-km area affected by this Pompton Lakes, Kinnelon, and Ridgefield. earthquake. 45 New Jersey 'Continued New Mexico

Intensity VI: Ridgefield (plaster fell). 5 January (G) Northwestern New Mexico Intensity V; All of the following Origin time: 06 23 32.9 communities reported that small objects Epicenter: 35.84 N., 108.34 W. shifted and many people were frightened: Depth: 25 km Belleville, Bogota, Cliffside Park, Magnitude: 5.0 mb, 4.6 ML Cresskill, East Rutherford, Englewood, Englewood Cliffs, Fairview, Fort Lee, USGS canvassed an area around the epicenter Garfield, Hackensack, Leonia, Lindhurst, within a radius of 300 km and mailed 359 Moonachie, New Mil ford, North Bergen, questionnaires. The damage that occurred Nutley, Palisades Park, Ridgefield Park, was generallly minor, consisting mostly of River Edge, Rutherford, Teaneck (press cracks in plaster and dry wall in several report), Wallington. Colorado and New Mexico towns and at Leupp, Ariz. Figure 15 shows the results of this Intensity IV: Alpine, Clifton (press canvass, combined with information from Dr. report), Demarest, Dumont, Edgewater, Allan R. Sanford, New Mexico Institute of Hasbrouck Heights, Little Ferry, Lodi, Mining Technology, and the results of a Maywood, North Arlington, Paramus, Rochelle USGS field survey. The earthquake was felt Park, Secaucus, Tenafly, Union City, over an area of approximately 115,000 sq km Weehawken, West New York, Wood-Ridge. of Arizona, Colorado, New Mexico, and Utah. Intensity III: Bergenfield, Elmwood Park, Glen Ridge, Guttenberg, Haworth, Jersey Intensity VI: City, Kearny, South Orange, Upper Arizona Leupp (cracked plaster). Montclair, Upper Saddle River, Westwood. Colorado Cahone (cracked plaster and dry

110' 109' 108' 107* 106" 105' 104' 103'

Figure 15.--Area affected by northwestern New Mexico earthquake of January 5 46 New Mexico Continued New Mexico Continued

wall, chimney cracked), Hesperus (new 24 June (G) Eastern New Mexico cracks in new concrete Origin time: 15 27 32.0 platform telephone report). Epicenter: 35.62 N., 103.28 W. New Mexico Crownpoint (cracked plaster, Depth: 5 km dry wall, and windows), Cuba (cracked Magnitude: 3.5 ML plaster), Cubero, Farmington (cracked Intensity V; Amistad. Postmaster at plaster), Fort Wingate (cracked plaster Tucumcari, 200 km north of epicenter, and dry wall), Gallup (minor reported everyone was frightened in Irene damage press report), Laguna, Mexican and Rosebud. Springs (cracked plaster and ceiling Intensity IV: Nara Visa. tiles), Regina, Standing Rock (cracked Intensity III: Capulin. plaster), Thoreau (cracked plaster and dry wall), Toadlena (cracked plaster), Vanderwagen (cracked plaster, moved Oklahoma furniture). Intensity V: 16 March (T) Eastern Oklahoma Arizona Fort Defiance, Indian Wells, Origin time: 07 39 54.5 Houck, Lukachukai, Lupton, .Navajo, St. Johns, Wide Ruins. Epicenter: 35.30 N., 95.50 W. Colorado Ignacio, Marvel. Depth: None computed. New Mexico Aztec, Bluewater, Brimhall, Magnitude: 2.3 ML Casa Blanca, Church Rock, Cuchillo, Fence Intensity data were provided by J. Lawson, Lake (bottles fell from shelf), Galina, Earth Sciences Laboratory, University of Gamerco, Grants (press report), Jemez Oklahoma, Leonard. Springs, Kirtland, Lake Valley School (50 km NNE of Crownpoint), Lumberton, Mentmore, Nageezi, Navajo Dam, Ponderosa, Intensity III: Eufaula, Stidham, Vivian. Prewitt, Pueblo Pintado School, Quemado, Intensity II: Hannah (8 km northwest of), Lenna. Ramah, Rehoboth, San Mateo, Tohatchi, Waterflow. Intensity IV: 30 March (G) Northwestern Oklahoma Arizona Chambers, Chinle, Petrified Forest Origin time: 09 27 01.0 National Park, Pinetop, Sanders, Sawmill, Epicenter: 36.61 N., 102.08 W. Woodruff. Depth: 5 km Colorado Bayfield, Chimney Rock, Chromo, Magnitude: 2.7 ML(T) Cortez, Creede, Dove Creek, Durango, ______Intensity V Boise City, Keyes. Maher, Mesa Verde, Pagosa Springs, Rico, Intensity IV: Griggs (press report). An Towaoc. earlier and smaller shock occurred at 07 05 New Mexico Blanco, Bloomfield, Continental (T). Divide, Dulce, La Jara, La Puente, 16 April (G) Western Oklahoma Llaves, Los Ojos, Magdalena, New Laguna, Origin time: 18 59 44.2 Nulan, Rutherton, San Rafael, Seboyeta, Epicenter: 36.11 N., 99.88 W. Silver City, Zuni. Depth: 5 km Utah Aneth. Magnitude: 3.4 mbLg(T) Intensity II Ij Intensity IV: Colorado Woody Creek, Yellow Jacket. Oklahoma Durham. New Mexico Milan. Texas Hi ggins. Utah Wellington. Intensity III: Intensity II: Okl ahoma Arnett. Colorado PIeasant View, Walsenburg. 17 April (T) Southern Oklahoma New Mexico Grady. Origin time: 02 48 Epicenter: 34.1 N., 97.4 W. 14 January (G) Central New Mexico Depth: None computed. Origin time: 07 01 32.0 Magnitude: 2.4 mbLg Epicenter: 34.17 N., 106.81 W. Intensity II: Wilson. Depth: None computed. Magnitude: None computed. 19 April (G) Western Oklahoma Intensity II: Lemitar, about 10 km east of Origin time: 04 42 42.2 Socorro. Epicenter: 36.13 N., 99.84 W. Depth: 5 km 20 May (G) Northwestern New Mexico Magnitude: 3.5 mbLg(T) Origin time: 19 43 21.9 Intensity IV: Epicenter: 35.47 N., 109.04 W. Okl ahoma Arnett, Cheyenne, Custer, Durham. Depth: 5 km Texas Hi ggins. Magnitude: 2.5 ML Intensity II: Intensity IV; Window Rock area. Oklahoma Reydon. 47 Oklahoma--Continued Oregon--Continued

20 September (T) Southern Oklahoma USGS canvassed an area around the epicenter Origin time: 09 40 within a radius of 250 km and mailed 355 Epicenter: Not located. questionnaires. The earthquake was felt Depth: None computed. over an area of approximately 35,000 sq km, Magnitude: 2.2 ML as shown in figure 16. Slight damage was Intensity II: Wilson. reported at Dufur and Wamic. A field investigation was made by Couch and 19 December (T) Southeastern Oklahoma Farooqui (1976), Oregon State University. Origin time: 08 26 36.7 The intensity data from this report are Epicenter: 34.92 N., 95.73 W. designated by (Z) in the listings below. Depth: 5 km Magnitude: 2.9 mbLg Intensity VI: Intensity II: McAlester (telephone Oregon--Dufur (slight damage), Wamic report). (plaster and dry wall cracked).

Intensity V: Oregon Oregon Antelope, Ashwood, Fossil, Gales Creek, Hood River (Z), Kahneeta (Z), 13 April (G) Northern Oregon Maupin, Parkdale, Post, Prineville, Origin time: 00 47 17.1 Rhododendron, South Junction Depot (Z), Epicenter: 45.22 N., 120.77 W. Spray, The Dalles (cracked windows press Depth: 15 km report), Tygh Valley, Warm Springs. Magnitude: 4.5 mb, 3.3 MS, 4.8 ML Washington Cook.

123° 122

44

Figure 16.--Area affected by northern Oregon earthquake of April 13 48 Oregon Continued Rhode Island Continued

Intensity IV: Worcester), Wakefield (north of Boston), Oregon Arlington, Bakeoven Road--22 km Edgartown, and Dennis Port, Mass.; and northwest of Shaniko (Z), Bend, Condon, Rogers, Conn, (where plaster reportedly Dayville, Friend, Grass Valley, Idanha, was cracked). Kent, Kimberly, Kinzua, Madras, Mitchell, Monument, Moro, Mosier, Oak Springs Fish Intensity VI; Hatchery (Z), Paulina, Pinegrove (Z), Connecticut Rogers (plaster cracked). Portland (press report), Rufus, Shaniko, Intensity V: Simnasho (Z), Terrebonne, Timberline Massachusetts Dartmouth, Fairhaven, Lodge, Wapunitia (Z), Wasco. Fall River (press report), Marshfield Washington--Brownstown, Carson, Hills, New Bedford, Somerset (press Centerville, Dallesport, Harrah, North report), Swansea, Westport (knocked Bonneville, Wishram. snow from roof press report), Intensity III; Westport Point. Oregon Bonnevi lie, Corvallis (Z), Redmond Rhode Island Bristol, Coventry, (Z), Rowena (Z), Tygh Ridge (Z). Exeter, Hope Valley, Jamestown, Intensity II: Little Compton, Newport (lamp fell Oregon--Alsea, Bates, lone, Pendleton. from table), North Kingstown (press Washi ngton--Central i a. report), North Scituate, Providence (press report), Tiverton, Warren, 17 April (G) Northern Oregon Warwick. Origin time: 02 11 44.4 Intensity IV: Epicenter: 45.08 N., 120.80 W. Massachusetts--Dennis Port, Edgartown, Depth: 2 km Elmwood, Leicester, Osterville, Magnitude: 4.2 ML Plymouth, Wakefield. Intensity II: Wasco County, Oreg. Rhode Island East Greenwich (press This is an aftershock of the earthquake of report), Middletown (press report), April 13 at 00 47 17.1 UTC. Oakland, Richmond. Intensity III: Massachusetts Brewster (press report), Puerto Rico Chatham (press report), Harwich (press report), Hyannis, Sandwich 29 March (G) Puerto Rico region (press report). Origin time: 06 15 41.6 Intensity II: Epicenter: 18.35 N., 65.12 W. Massachusetts Dennis (press report), Depth: 110 km West Falmouth, Yarmouth (press Magnitude: 4.7 mb report). Intensity III: San Juan (I si a Verde Interna- tional Airport). Intensity II: Vieques, P.R., and on all three U.S. Virgin Islands. Tennessee 13 June (G) Mona Passage Origin time: 19 06 27.4 4 February (G) Tennessee-Georgia border Epicenter: 19.44 N., 67.92 W. Origin time: 19 53 52.9 Depth: 51 km Epicenter: 35.00 N., 84.75 W. Magnitude: 5.4 mb Depth: 5 km Intensity II: San Juan. Magnitude: 3.0 mbLg(V) The epicenter of this earthquake is located east of Chattanooga, Tenn., Rhode Island near Conasauga, in the Lake Ocoee Dam area. The shock was felt at a few towns in that region. 11 March (C) Southeastern Rhode Island Origin time: 08 29 32.2 Intensity VI: Epicenter: 41.56 N., 71.21 W. Tennessee Conasauga (cracked Depth: 0 km masonry; cracks in 4-year-old Magnitude: 3.5 mbLg cement-block building north of city; cracks in chimney of house 2 The earthquake was generally felt in towns km from Ball Play Creek, along along the eastern Rhode Island-eastern Highway 411 (N)). Massachusetts border region, from Intensity V: Oakland, R.I., south to Newport, and from Georgia Baxley, Cisco, Lyons, Somerset, Mass., south to New Bedford and Reidsville, Uvalda (N). Westport Point. Some isolated felt Intensity IV: reports include Leicester (near Tennessee--Copperhil1, Duck town. 49 Tennessee Conti nued Utah Continued

Intensity III: 5 November (U) Northern Utah Tennessee Chattanooga (telephone Origin time: 01 15 06.9 report). Epicenter: 41.82 N., 112.69 W. Intensity II: Depth: 7 km Georgia Dalton, Hiawassee. Magnitude: 3.4 ML Intensity II: Snowville.

Texas 5 November (U) Northern Utah Origin time: 02 48 55.4 Epicenter: 41.81 N., 112.70 W. 19 January (G) Southwestern Texas Depth: 7 km Origin time: 04 03 30.5 Magnitude: 4.1 ML Epicenter: 31.90 N., 103.08 W. Intensity V: Utah Howell (small objects Depth: 1 km moved), Lewiston, Riverside. Magnitude: 3.3 ML Intensity IV: Utah Hyrum, Snowville. Intensity IV Kermit. Idaho -Hoibrook, Stone. Intensity III: Utah Portage. 22 January (G) Southwestern Texas Intensity II: Utah Plymouth. Origin time: 07 21 57.0 Epicenter: 31.90 N., 103.07 W. 5 November (U) Northern Utah Depth: 1 km Origin time: 10 58 03.5 Magnitude: 2.8 ML Epicenter: 41.82 N., 112.69 W. Intensity III: Kermit (press report). Depth: 7 km Magnitude: 3.2 ML 25 January (G) Southwestern Texas Intensity II: Snowville. Origin time: 04 48 27.9 Epicenter: 31.90 N., 103.08 W. Depth: 2 km Virginia Magnitude: 4.1 ML Intensity V: Texas Kermit. 13 September (G) Virginia-North Carolina border Intensity IV: Origin time: 18 54 37.1 New Mexico Jal. Epicenter: 36.60 N., 80.81 W. Texas Notrees. Depth: 5 km Intensity III: Magnitude: 3.3 mbLg(V) New Mexico Lea County (press reports), Texas Ector and Winkler Counties. USGS canvassed an area around the epicenter within a radius of 150 km and mailed 356 questionnaires. In addition, data were Utah provided by G. A. Bollinger, Virginia Polytechnic Institute and State University, at Blacksburg, and by Law Engineering 11 February (U) Northern Utah Testing Company, Marietta, Georgia. These Origin time: 03 28 14.7 data were evaluated by the USGS, and the Epicenter: 41.27 N., 111.84 W. combined results are listed below. The Depth: 13 km earthquake was felt over an area of Magnitude: 2.7 ML . approximately 17,500 sq km (fig. 17). Intensity III: Ogden (U). Intensity VI: North Carolina Mount Airy (bricks fell 27 February (G) Northern Utah from chimney; pictures fell off piano; Origin time: 07 18 16.4 pictures dislodged from wall), Toast Epicenter: 41.24 N., 111.27 W. (cracked masonry and plaster; guards on Depth: 5 km fluorescent light fixtures and metal Magnitude: 2.4 ML(U) sorting cases in post office rattled Intensity II: Hill AFB, Ogden, violently; loud noises resembling Pleasant View, Roy (all from press explosions). reports). Intensity V: North Carolina Advance, Dobson (small 15 June (U) Northern Utah objects shifted), East Bend, Ennice, Origin time: 02 08 10.4 Glade Valley, Pilot Mountain, Piney Epicenter: 41.89 N., 112.44 W. Creek, Rural Hall, Si loam, Sparta Depth: 1 km (pictures tilted on wall), State Road, Magnitude: 3.1 ML Thurmond, White Plains. Intensity III: Blue Creek Valley (press Virginia Cana, Fancy Gap (small objects report). overturned), Fries, Galax, Lambsburg. 50 Virginia Continued Virginia Continued

81 80 79 78 77 76 WEST VIRGINIA VIRGINIA oAppomattox

37

oWilkesboro NORTH CAROLINA 36

EXPLANATION & Epicenter 7 Felt at intensity 7 0 Not felt 0 50km 35 Figure 17.--Area affected by Virginia-North Carolina border earthquake of September 13

Intensity IV: Intensity III: North Carolina Ararat, Barium Springs, North Carolina--Blowing Rock, Boomer, Belle Island (two shocks felt several Denton, Kannapolis, Moyock (lasted longer seconds apart at Currituck Sound), than 10 seconds), Needmore, Traphill. Boonville, Concord (north-south motion Virginia Ararat, Fancy Gap, Roanoke, Trout reported), El kin (loud sound like an Dale. explosion rattled windows and doors; Intensity II; water in bathtub rippled), Grandy (three North Carolina Charlotte, Longview, Manteo shocks felt), Hamptonville, Harmony, (two shocks felt), Mt. Pleasant. Hillsville, Jonesville, Kitty Hawk (6.3 South Carolina Columbia (felt on upper km north on Currituck Sound; two tremors floors of an eight-story noted, each lasting several seconds and building telephone report), Greenville separated by several seconds, described (telephone report). as relatively high-frequency vibration Virginia--Indian Valley, Laurel Fork, that did not vary in intensity from Marion. beginning to end, but began and ceased abruptly ), Knotts Island (rattling of Virgin Islands windows and doors, lasting about 10 seconds), Landis, Lewisville, Lowgap, Maple (Currituck County; three shocks 15 October (G) Virgin Islands felt in about 5 minutes, two close Origin time: 19 50 42.0 together), Millers Creek, Pilot Mountain, Epicenter: 18.92 N., 64.47 W. Powells Point (on Albemarle Sound), Depth: 45 km Roaring River, Ronda, Salisbury (southern Magnitude: 5.0 mb, 5.4 mb (L). Rowan County), Scottville, Sparta, Intensity V: Statesville, Union Grove, Westfield, Puerto Rico San Juan (Isla Verde Whitehead, Mil bar, Woodleaf. International Airport). Virginia Austinville, Claudville, Cripple Intensity IV: Creek, Hillsville, Independence, Mouth of Virgin Islands Cruz Bay. Wilson, Stuart, Woodlawn. Cuba Guantanamo Bay. West Virginia Anawalt. Puerto Rico Fajardo. 51 Washington Washi ngton Conti nued

5 January (W) Puget Sound, Wash. Bay, Harrison Hot Springs, Harrison Origin time: 13 25 43.8 Mills, Honeymoon Bay, Hopkins Landing, Epicenter: 47.46 N., 122.60 W. Huntington, Lindell Beach, Madeira Depth: 42 km Park, Maple Ridge, Matsqui, Mayne, Magnitude: 2.7 ML(G), 3.3 Mesachie Lake, Mission City, Nanoose Intensity IV: Burley, Olympia, Port Bay, New Westminster, North Surrey, Orchard. North Vancouver, Parksville, Port Intensity III: Bremerton (press Alberni, Port Coquitlam, Port Mellon, report), Eatonville, La Grande, Port Renfrew, Port Washington, Roberts Preston. Creek, Rosedale, Saanichton, Saturna, Intensity II; Steilacoom, Tacoma Sechelt, Shawnigan Lake, Sidney, (press report). Sooke, South Wellington, Squamish, Thetis Island, Vancouver (power 27 January (W) Northwestern Washington outage), Vedder Crossing, Whonock, Origin time: 03 09 31.3 Woodfibre. Epicenter: 47.88 N., 122.17 W, Washington Acme, Alderwood Manor, Depth: 19 km Anacortes, Arlington, Bellingham, Magnitude: 2.1 MUG), 2.9 Blakely Island, Blanchard, Bothell, Intensity IV: Snohomish. Bow, Burlington, Carlsborg, Chimacum, Intensity III; Everett. Clallam Bay, Clinton, Concrete, Custer, Darrington, Eastsound, Edison, 31 January (W) Northwestern Washington Enumclaw, Everett, Everson, Ferndale, Origin time: 12 27 14.0 Freeland, Friday Harbor, Gardiner, Epicenter: 48.35 N., 122.32 W. Glacier, Gold Bar, Hamilton, Index, Depth: 18 km Joyce, Lake Stevens, Lopez, Lyman, Magnitude: 2.4 MUG), 3.6 Lynden, Marblemount, Marietta, Monroe, Intensity IV; Camano Island, Silvana, Mount Vernon, Nooksack, Nordland, Oak Stanwood. Harbor, Olga, Orcas, Point Roberts, Intensity II: Mount Vernon. Preston, Quilcene, Roche Harbor, Rockport, Sedro Wool ley, Sekiu, Shaw 16 May (W) Vancouver Island region Island, Silvana, Skykomish, Origin time: 08 35 14.8 Snoqualmie, Startup, Sumas, Epicenter: 48.80 N., 123.36 W. Wickersham. Magnitude: 5.1 mb (G) Depth: 62 km Intensity IV: British Columbia Blubber Bay, Bowen USGS canvassed an area around the Island, Brittania Beach, Cassidy, epicenter within a radius of 250 km and Cultus Lake, Fort Langley, Gibsons, mailed 296 questionnaires. The Hope, Hornby Island, Icco, James earthquake was felt over an area of Island, Mount Currie, North Burnaby, approximately 77,000 sq km of Washington Pender Island, Pitt Meadows, Port and British Columbia, as shown in figure Moody, Powell River, Qualicum Beach, 18. Minor damage occurred at Deming, Royston, Stewardson Inlet, Union Bay, Wash., and Lake Cowichan and Victoria, Westholme, Yarrow, Youbou. B.C. The Canadian data were supplied by Gary Rogers, Victoria Geophysical Washington Aberdeen, Birch Bay (press Observatory, British Columbia, and report), Blaine (press report), reevaluated by the USGS. Bremerton, Carnation, Coupeville, Deer Harbor, Fall City, Grayland, Intensity VI: Greenbank, Hansville, Holden Village, British Columbia Abbotsford, Duncan, Indianola, La Conner, Langley, Mount Essondale, Gold River, Ladysmith, Lake Vernon, Mukilteo, Olympia (press Cowichan (waterline broken), Langley, report), Port Angeles, Ravensdale, Mill Bay, Mount Lehman, Nanaimo, Roll ingbay, San Juan Island (press Richmond, Steveston, Surrey, Victoria report), Seabeck, Seattle, Stanwood, (one chimney damaged, one brick fell), Waldron. West Vancouver, White Rock. Washington Deming (plaster and dry wall Intensity III- cracked), Maple Falls. British Columbia Cumberland, Gillies Intensity V: Bay, Mansons Landing. British Columbia Agassiz, Aldergrove, Washington Duvall (8 km northeast of), Bamfield, Boston Bar, Bradner, Mercer Island. Brentwood Bay, Burnaby, Chemainus, Chilliwack, Cobble Hill, Coquitlam, Cowichan, Crofton, Delta, Dewdney, Intensity II: Fulford Harbor, Gabriola, Galiano, British Columbia Barnet. Gambier, Ganges, Garden Bay, Half Moon Washington Dockton, Snohomish. 52 Washington--Continued Washi ngton Conti nued

126

6 Felt at intensity 6 ° Not felt

Figure 18.--Area affected by Vancouver Island earthquake of May 16

2 September (W) Northwestern Washington Intensity V; Bremerton, Carlsborg, Origin time: 13 36 11.0 Coupeville, Eastsound, Everett, Gardiner, Epicenter: 48.21 N., 122.76 W. Greenbank, Hadlock (small objects and Depth: 24 km furniture moved), Joyce, La Connor (small Magnitude: 4.3 mb(G), 4.0 ML(G) objects moved), Lopez (small objects moved), Lummi Island, Lynnwood, Oak Harbor This earthquake was widely felt in the (water sloshed; small objects shifted), Washington Counties of Clallam, Island, 01ga, Orcas, Port Angeles, Port Townsend Jefferson, King, Kitsap, San Juan, Skagit, (small objects moved), Quilcene, Seattle, Snohomish, and Whatcom, as well as in Shaw Island (small objects moved), Vancouver and Victoria in British Columbia Stanwood, Waldron, Whidbey Island (small (press report). USGS canvassed an area objects shifted). around the epicenter within a radius of 125 Intensity IV; Anacortes, Blakely Island, km and mailed 244 questionnaires. This Bothell, Brinnon, Chimacum, Clear!ake, earthquake was felt throughout the Puget Ferndale, Freeland, Friday Harbor, Lyman, Sound area (fig. 19). Magnolia, Port Ludlow, Sequim, Skykomish. 53 Washi ngton---Conti nued Washi ngton Conti nued

49e

EXPLANATION Epicenter

7 Felt at intensity 7

o Not felt

48'

Figure 19. Area affected by northwestern Washington earthquake of September 2

Intensity III: Bow, Keyport, Mt. Vernon Intensity VI: Tacoma (broken glassware, (press report). other slight damage, many awakened and Intensity II: Capitol Hill. frightened press report). Intensity V: Allyn (small objects moved), 8 September (W) Northwestern Washington Aloha, Anderson Island, Auburn, Bel fair, Origin time: 08 21 01.6 Burley, Carnation, Dockton, East Olympia, Epicenter: 47.38 N., 123.08 W. Fox Island, Grapeview, Lilliwaup, Depth: 48 km Longbranch (small objects moved), Lopez Magnitude: 4.6 mb(G), 3.9 MS(G), 4.8 ML(G) (furniture moved), Lyman, Manchester, Matlock (small objects moved), McMillin, USGS canvassed an area around the epicenter Mercer Island (press report), Milton, within a radius of 150 km and mailed 336 Mineral, Nordland (small objects moved), questionnaires. The earthquake was felt Oakville, 01ga, Olympia, Pacific, Puyallup, throughout the Puget Sound area (fig. 20). Redondo, Renton, Rochester (small objects 54 Washl ngton 'Contl nued Washington Continued

124< 123' 122 (

EXPLANATION M Epicenter 7 Felt at intensity 7 o Not felt

48C

WASHINGTON

47

Figure 20. Area affected by northwestern Washington earthquake of September 8

shifted), Rollingbay, Seattle, Shaw Island, Intensity V: Elbe (furniture moved), Shelton, South Col by (small objects Glenoma, La Grande, Mineral (furniture shifted), Startup, Tahuya, Tracyton, Union, moved). Vashon, Victor (press report), West Seattle Intensity IV: Ashford, Morton, Randle, (press report). Silver Creek. Intensity IV; Ashford, Bremerton, Carbonado, Intensity III: Salkum. Fort Lewis, Hoodsport, Indianola, Joyce, Intensity II; Eatonville, McKenna, Lakebay, Lynnwood, Malone, McCleary, Mossyrock. Normandy Park (press report), Randle, Seattle-Tacoma Airport (control-tower personnel estimated tower swayed 3 m), West Virginia Sumner. Intensity III: Duvall, Seabeck. Intensity II: Auburn, Suquamish. 6 May (A) Northern West Virginia Origin time: 18 46 08.1 Epicenter: None computed. 14 October (W) Southwestern Washington Depth: None computed. Origin time: 21 39 17.7 Magnitude: None computed. Epicenter: 46.66 N., 122.34 W. Intensity IV; Morgantown (U.S. Bureau of Depth: 30 km Mines station; glasses rattled, floor Magnitude: 3.1 ML(G) moved). 55 West Virginia Continued Wyomi ng Conti nued

19 June (G) Southern West Virginia Intensity IV: Origin time: 05 54 13.9 Montana West Yellowstone. Epicenter: 37.36 N., 81.62 W. Wyomi ng Canyon Village, Madison Junction, Depth: 5 km Mammoth, Old Faithful. Magnitude: 4.7 mb, 3.0 mbLg(V) Intensity III: Intensity V: Berwind, Wilcoe. Montana Corwin Springs. Intensity IV: Welch, Wilcoe. Intensity III:Coa1wood, Gary. 19 October (G) Yellowstone National Park Origin time: 07 24 34.6 Epicenter: 44.80 N., 110.70 W. Depth: 5 km Wyomi ng Magnitude: 5.3 mb, 4.1 ML Intensity IV; Montana West Yellowstone. 27 January (G) Southern Wyoming Wyoming Canyon Village, Madison Junction, Origin time: 10 54 38.7 Mammoth, Old Faithful. Epicenter: 41.95 N., 107.22 W. Depth: 5 km 17 November (G) Yellowstone National Park Magnitude: 2.3 ML Origin time: 14 34 33.4 Intensity V: Rawlins (knocked lamp Epicenter: 44.75 N., 110.86 W. off table, pictures off wall press report). Depth: 5 km Magnitude: 3.0 ML(A), 3.7 ML(D) 7 June Yellowstone National Park Intensity IV Canyon Village. Origin time: 04 48 Intensity III: Madison Junction. Epicenter: Not located. Depth: None computed. 17 November (G) Yellowstone National Park Magnitude: None computed. Origin time: 14 57 38.6 Intensity V: Madison Junction, Old Epicenter: 44.74 N., 110.83 W. Faithful. Depth: 5 km Magnitude: 3.0 ML(A) 7 June Yellowstone National Park Intensity III: Madison Junction. Origin time: 12 07 Epicenter: Not located. 27 November (G) Yellowstone National Park Depth: None computed. Origin time: 01 09 35.2 Magnitude: None computed. Epicenter: 44.66 N., 110.82 W. Intensity V: Canyon Village, Madison Depth: 5 km Junction, Old Faithful. (Residents Magnitude: 3.5 ML(A) were awakened and frightened; most Intensity III Madison Junction. were living in old wood cabins or trailers.) 27 November (G) Yellowstone National Park Origin time: 19 18 57.9 3 September (G) Northeastern Wyoming Epicenter: 44.85 N., 110.97 W. Origin time: 04 18 16.2 Depth: 5 km Epicenter: 44.04 N., 106.15 W. Magnitude: 3.6 ML(A) Depth: 10 km Intensity II Canyon Village, Madison Magnitude: 4.8 mb, 4.2 ML Junction. Intensity____ V: Kaycee (small objects and light furniture moved; building creaked, 8 December (G) Yellowstone National Park several frightened). Origin time: 14 40 59.1 Epicenter: 44.76 N., 110.79 W. Depth: 5 km 19 October (G) Yellowstone National Park Magnitude: 5.5 mb, 4.6 ML Origin time: 06 18 35.3 Intensity V: Epicenter: 44.74 N., 110.81 W. Montana Corwin Springs (small objects Depth: 4 km moved). Magnitude: 5.3 mb, 4.0 ML Intensity IV: Montana Gardiner, West Yellowstone. This earthquake was felt over an area of Intensity III: approximately 3,000 sq km in the Wyoming Canyon Village, Madison Yellowstone National Park. Both tremors Junction, Mammoth Hot Springs, Old (the second occurred at 07 24 34.6) were Faithful. described as a strong, quick jolt or rocking action lasting a few seconds. The 9 December (G) Yellowstone National Park only direction sensed was at Canyon where Origin time: 22 36 23.7 the winterkeeper reported tremors coming Epicenter: 44.77 N., 110.80 W. from the west (R. A. Hutchinson, National Depth: 5 km Park Service, written commun., 1976). Magnitude: 4.5 mb, 5.1 ML, 4.7 ML(D) 56 Wyoming Continued Wyomi ng Conti nued

Intensity V: Wyoming Mammoth Hot Springs (very minor Montana Corwin Springs (small objects damage). moved), West Yellowstone. (Both areas reported cracked windows; Wyoming Canyon Village (small objects Christmas decorations and household fell, Gibbon River turbid). items were knocked to the floor.) Intensity IV: Intensity IV: Montana--Harri son. Wyoming Canyon Village, Devil's Slide Wyoming Madison Junction, Mammoth. area of Yellowstone Valley (south of Intensity III: Corwin Springs, Mont.), Madison Montana Gall atin Gateway (telephone Junction, Old Faithful. report), Virginia City. Intensity III; Wyoming Old Faithful. Montana West Yellowstone. 16 December (G) Yellowstone National Park 20 December (G) Yellowstone National Park Origin time: 00 28 21.4 Origin time: 01 34 16.7 Epicenter: 44.64 N., 111.05 W. Epicenter: 44.84 N., 110.83 W. Depth: 5 km Depth: 5 km Magnitude: 3.0 ML(A) Magnitude: 4.4 mb, 4.3 ML Intensity IV: Madison Junction. The intensity data below were furnished by R. A. Hutchinson, National Park Service 19 December (G) Yellowstone National Park geologist, Yellowstone National Park, Wyo. Origin time: 17 10 15.6 Epicenter: 44.77 N., 110.80 W. Intensity IV: Depth: 5 km Montana Gardi ner. Magnitude: 4.9 mb, 4.5 ML Wyoming Canyon Village, Madison Junction, Mammoth Hot Springs, Mary The intensity data below were furnished by Mountain Patrol Cabin. R. A. Hutchinson, National Park Service Intensity III; geologist, Yellowstone National Park, Wyo, Montana Corwin Springs, West Yellowstone. Wyoming Devil's Slide area of Yellowstone Intensity VI: Valley (south of Corwin Springs, Mont.), Montana Gardiner (very minor damage). Old Faithful.

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65 TABLE 1. SUWIARY OF EARTHQUAKES FELT IN U.S. FOR 1976 CONTINUED GEOGRAPHIC MAXIMUM DATE ORIGIN TINE COORDINATES SOURCE REGION INTENSITY DEPTH MAGNITUDE UT LAT. LONG. H H S DEC. OEG. HAHAII (CONTINUED)

DEC 9 00 15 42. 5 19 .34 155,,18 H ISLAND OF HAWAII II 09 KM 2.9 HL DEC 9 04 50 26. 3 19 .43 155.,28 H ISLAND OF HAHAII II 01 KM 2.0 ML DEC 10 01 28 49. 9 19 .40 155,>29 H ISLAND OF HAHAII III 03 KM 3.0 ML DEC 12 09 39 36. 6 19 .22 155,,47 H ISLAND OF HAWAII II 09 KM 2.8 ML DEC 14 03 26 42. 0 19 .34 155,,13 H ISLAND OF HAHAII II 10 KM 3.4 ML DEC 17 13 39 14. 5 19 .43 155,,20 H ISLAND OF HAHAII II 01 KM 2.9 ML DEC 10 14 01 00. 5 19 .34 155,.12 H ISLAND OF HAHAII V 09 KM 4.8 ML, 5.0 MB<6> DEC 22 19 03 32. 4 19 .40 155,,27 H ISLAND OF HAHAII II 03 KM 2.2 HL DEC 25 17 01 15. 4 19 .64 156,,01 H ISLAND OF HAHAII III 09 KM 3.3 HL DEC 27 14 15 20. 6 19 .39 155.,25 H ISLAND OF HAHAII III 05 KM 3.3 HL DEC 27 16 24 27. 3 19 .32 155,,27 H ISLAND OF HAHAII III 10 KM 3.1 HL DEC 27 19 19 27. 0 19 .40 155,,25 H ISLAND OF HAHAII II 03 KM 2.5 HL DEC 29 01 17 36. 6 19 .40 155,,28 H ISLAND OF HAWAII II 03 KM 2.8 HL DEC 29 05 37 04. 8 19 .32 155,,20 H ISLAND OF HAWAII III 10 KM 3.2 HL DEC 29 13 45 37. 4 19 .39 155,,29 H ISLAND OF HAWAII II 02 KM 2.4 ML DEC 30 02 44 25. 6 19 .33 155,,19 H ISLAND OF HAWAII II 09 KM 2.9 HL DEC 30 05 26 26. 9 19 .39 155,,24 H ISLAND OF HAWAII III 05 KM 3.0 HL DEC 30 10 47 36. 9 18 .16 155,.25 H ISLAND OF HAWAII II 07 KM 3.9 HL DEC 30 14 19 51. 5 19 .33 155,,27 H ISLAND OF HAWAII II 10 KM 3.0 ML IDAHO

JUN 14 09 37 57. 0 42 .12 112,.48 U EASTERN IDAHO IV 07 KM 3.6 ML JUL 26 10 45 28. 2 45 .02 114,,18 G WESTERN IDAHO V 10 KM 4.3 HB, 4.4 HL NOV 1 22 22 51. 1 44 .26 114,,97 G WESTERN IDAHO IV 05 KM 3.7 HL(A), 3.9 ML(D) INDIANA

APR 8 07 38 53. 0 39 .35 086,,68 G CENTRAL INDIANA V 20 KM 3.0 HBL6 JUN 13 18 55 18. 5 I INDIANAPOLIS, IND. II NONE COMPUTED JUN 13 18 58 28. 5 I INDIANAPOLIS, INO. II NONE COHPUTED KENTUCKY JAN 19 06 20 39. 5 36 .88 083,.02 G EASTERN KENTUCKY VI 05 KM 4.0 MB, 3.8 HL(S) APR 15 07 03 34. 9 37 .41 087,.31 G WESTERN KENTUCKY V 15 KM 3.3 HBLG(V) MAINE

APR 15 10 36 04. 8 44 .24 070..14 J SOUTHWESTERN MAINE III 00 KM 2.4 MBLG OCT 23 20 58 18. 0 47 .82 069,,79 0 SOUTHERN QUEBEC, CANADA IV 18 KM 3.8 MB(G>, 4.2 MBLG MASSACHUSETTS

HAR 14 23 12 24.6 41.66 069.97 CAPE COO, MASS. 00 KM 3.0 ML(L)

SEE FOOTNOTES AT END OF TABLE TABLE 1. SUMMARY OF EARTHOUAKES FELT IN U.S. FOR 1976 - CONTINUED

GEOGRAPHIC HAXINUH

DATE ORIGIN TIHE COORDINATES SOURCE REGION INTENSITY DEPTH HAGNITUOE

UT LAT. LONG. H H S DEC. DEC.

HASSACHUSETTS (CONTINUED)

NAY 10 01 34 20.5 071.01 SOUTHEASTERN HASSACHUSETTS 00 KM 2.7 MBLG

MICHIGAN

FEB 21 14 02.0 41.96 082.67 SOUTHWESTERN ONTARIO* CANADA IV 10 KM 3.4 ML

MISSOURI JAN 23 00 56 39. 6 36 .55 089. 60 S NEW MADRID* MO. IV 09 KM 2.0 ML NAY 22 07 40 46. 0 36 .04 089. 84 S NEW MADRID REGION V 10 KM 3.2 MBLG DEC 13 08 35 54 9 37 .80 098. 24 S EASTERN MISSOURI V 05 KM 3.5 ML MONTANA JAN 21 13 43 29. 6 48 .22 114. 10 G NORTHWESTERN HONTANA IV 05 KM 3.1 ML FEB 13 06 13 43. 1 46 .75 112. 13 G WESTERN MONTANA IV 01 KM 3.8 ML APR 5 02 40 07 4 46 .13 111. 68 G WESTERN MONTANA IV 05 KM 3.6 MLCO) APR 24 08 49 12. 0 48 .26 114. 09 G WESTERN MONTANA II 05 KM 2.9 ML JUL 28 05 06 16 * 9 47.55 112. 73 G WESTERN MONTANA IV 05 KM 3.5 ML(D)« 3*5 ML NOV 27 00 24 46 1 44 .64 111. 14 G HEBGEN LAKE REGION IV 09 KM 3.3 ML(A), 3.7 ML(D) DEC 8 22 10 42 . 3 44 .75 111. 05 G HEBGEN LAKE REGION III 05 KM 3.5 ML DEC 20 17 07 10 . 5 44 .50 111. 07 G HEBGEN LAKE REGION, MONT. III 09 KM 3.3 ML(A) NEVADA FEB 8 06 09 26. 5 39 .47 119. 76 G NORTHWESTERN NEVADA IV 05 KM 3.4 ML(B) JUN 10 10 39 35 9 39 .63 115. 85 G CENTRAL NEVADA V 02 KM NONE COMPUTED. JUN 24 00 24 45. 1 39 .45 119. 53 G WESTERN NEVADA V 02 KM 3.5 ML(B) JUN 29 13 10 48 8 39 .45 119. 54 G WESTERN NEVADA V 06 KM 3*5 ML(BI AUG 2 08 14 07 4 38 .38 118. 19 G CALIFORNIA-NEVADA BORDER REGION IV 08 KM 4.8 MB* 4.3 ML(B) AUG 14 07 50 44 . 9 39 .48 119. 62 G WESTERN NEVADA II 07 KM 2.2 ML AUG 14 07 58 32 . 4 39 .45 119. 54 G WESTERN NEVADA II 04 KM 3.1 ML(8) AUG 14 08 08 03 1 39 .43 119. 64 G WESTERN NEVADA II 06 KM 2.2 ML OCT 4 14 48 39 0 36 .03 114. 74 G SOUTHERN NEVADA III 05 KM 3.0 ML OCT 19 01 59 10 . 6 35 .98 114. 82 G SOUTHERN NEVADA III 05 KM NONE COMPUTED. NOV 17 08 23 35 0 40 .54 115. 99 G NORTHERN NEVADA IV 15 KM 3.9 ML(8t NEW JERSEY

NAR 11 21 07 20 4 40 .96 074. 37 L NORTHEASTERN NEW JERSEY VI 04 KM 2.4 MBLG APR 13 15 39 13 2 40 .84 074. 05 L NORTHEASTERN NEW JERSEY VI 02 KM 3.1 MBLG NEW MEXICO

JAN 5 06 23 32.9 35.84 108.34 NORTHWESTERN NEW MEXICO VI 25 KM 5.0 MB* 4.6 ML

SEE FOOTNOTES AT END OF TABLE TABLE 1. SUMMARY OF EARTHQUAKES FELT IN U.S. FOR 1976 - CONTINUED

GEOGRAPHIC MAXIMUM

DATE ORIGIN TINE COORDINATES SOURCE REGION INTENSITY DEPTH MAGNITUDE UT LAT. LONG. H M S DEC. DEC

NEH MEXICO (CONTINUED)

JAN It 07 01 32. 0 3%. 17 106. 1 G CENTRAL NEH MEXICO II NONE COMPUTED. MAY 20 19 <»3 21. 9 35. l»7 109. 0«» G NORTHWESTERN MEXICO IV 05 KM 2.5 ML JUN 2* 15 27 32. 0 35. 62 103. 28 G EASTERN NEH MEXICO V 05 KM 3.5 ML OKLAHOMA MAR 16 07 39 5k. 5 35. 30 095. 50 T EASTERN OKLAHOMA III 2.3 ML MAR 30 09 27 01. 0 36. 61 102. OS G NORTHWESTERN OKLAHOMA V 05 KM 2.7 MLIT) APR 16 18 59 kk. 2 36. 11 099. 88 G WESTERN OKLAHOMA IV 05 KM 3.% MBLGCT) APR 17 02 <*8 3%. 1 097. k T SOUTHERN OKLAHOMA II 2.% MBLG APR 19 Ot «2 *2. 2 36. 13 099. 8% G WESTERN OKLAHOMA IV 05 KM 3.5 MBLG(T) SEP 20 09 <»0 T SOUTHERN OKLAHOMA II 2.2 ML DEC 19 08 26 36. 7 3%. 92 095. 73 T SOUTHEASTERN OKLAHOMA II 05 KM 2.9 MBLG OREGON

APR 13 00 k7 17. 1 *5. 22 120. 77 G NORTHERN OREGON VI 15 KM k.5 MBt 3.3 MS t *. ML APR 17 02 11 <»*. * *5. 08 120. 0 G NORTHERN OREGON II 02 KM *.2 ML PUERTO RICO

MAR 29 06 15 M. 6 18. 35 065. 12 G PUERTO RICO REGION III 110 KM *.7 MB JUN 13 19 06 27. k 19. kk 067. 92 G MONA PASSAGE II 51 KM 5.% MB

RHODE ISLAND

NAR 11 08 29 32.2 M.56 071.21 SOUTHEASTERN RHODE ISLAND VI 00 KM 3.5 MBLG

TENNESSEE

FEB * 19 53 52.9 35.00 08l».75 TENNESSEE-GEORGIA BORDER VI 05 KM 3.0 MBLG(V)

TEXAS

JAN 19 Ql» 03 30. 5 31 .90 103,,08 G SOUTHWESTERN TEXAS IV 01 KM 3.3 ML JAN 22 07 21 57. 0 31 .90 103.,07 G SOUTHWESTERN TEXAS III 01 KM 2.8 ML JAN 25 Ol> «,« 27. 9 31 .90 103,.08 G SOUTHWESTERN TEXAS V 02 KM t.l ML UTAH

FEB 11 03 28 1<». 7 «»1 .27 111.,8<* U NORTHERN UTAH III 13 KM 2.7 ML FEB 27 07 18 16. i» M 2<» 111.^27 G NORTHERN UTAH II 05 KM Z.k MLCU) JUN 15 02 08 10. k ki .89 112,,kk U NORTHERN UTAH III 01 KM 3.1 ML NOV 5 01 15 06. 9

SEE FOOTNOTES AT END OF TABLE TABLE 1. SUMMARY OF EARTHOUAKFS FELT IN U.S. FOR 1976 - CONTINUED GEOGRAPHIC HAXINUH

DATE ORIGIN TIME COORDINATES SOURCE REGION INTENSITY DEPTH HAGNITUDE UT LAT. LONG. H H S OEG. DEC.

UTAH (CONTINUED)

NOV 5 10 58 03.5 41.82 112.69 NORTHERN UTAH II 07 KM 3.2 ML

VIRGINIA

SEP 13 18 5% 37.1 36.60 080.81 VIRGINIA-NORTH CAROLINA REGION VI 05 KM 3.3 MBLG(V)

VIRGIN ISLANDS

OCT 15 19 50 42.0 18.92 064.47 VIRGIN ISLANDS V 45 KM 5.0 MB* 5.4 HBIL1

WASHINGTON

JAN 5 13 25 43. 8 47..46 122 . 60 W PUGET SOUND, MASH. IV 42 KM 2.7 HLtCI* 3.3 HL

WEST VIRGINIA

MAY 6 18 46 00. 1 X NORTHERN WEST VIRGINIA IV NONE COMPUTED JUN 19 05 54 13. 9 37..36 081 . 62 G SOUTHERN WEST VIRGINIA V 05 KM 4.7 MB, 3.0 MBLGfVI

WYOMING

JAN 27 10 54 38. 7 41,,95 107 . 22 G SOUTHERN WYOMING V 05 KM 2.3 ML JUN 7 04 48 YELLOWSTONE NATIONAL PARK V NONE COMPUTED. JUN 7 12 07 YELLOWSTONE NATIONAL PARK V NONE COMPUTED. SEP 3 04 18 16. 2 44.,04 106 . 15 G NORTHEASTERN WYOMING V 10 KM 4.8 MB* 4.2 ML OCT 19 06 18 35. 3 44.,74 110 . 81 G YELLOWSTONE NATIONAL PARK IV 04 KM 5.3 MB* 4.0 ML OCT 19 07 24 34. 6 44.,80 110 . 70 G YELLOWSTONE NATIONAL PARK IV 05 KM 5.3 MB* 4.1 ML NOV 17 14 34 33. 4 44.,75 110 . 86 G YELLOWSTONE NATIONAL PARK IV 05 KM 3.0 NL(A), 3.7 ML(OI NOV 17 14 57 38. 6 44.,74 110 . 83 G YELLOWSTONE NATIONAL PARK III 05 KM 3.0 MLCAI NOV 27 01 09 35. 2 44.,66 110 . 82 G YELLOWSTONE NATIONAL PARK III 05 KM 3.5 ML(A) NOV 27 19 18 57. 9 44.,85 110 . 97 G YELLOWSTONE NATIONAL PARK II 05 KM 3.6 ML(AI DEC 8 14 40 59. 1 44.,76 110 . 79 G YELLOWSTONE NATIONAL PARK V 05 KM 5.5 MB* 4.6 ML DEC 9 22 36 23. 7 44.,77 110 « 80 G YELLOWSTONE NATIONAL PARK V 05 KM 4.5 MB* 5.1 ML, 4.7 ML DEC 16 00 28 21. 4 44.,64 111 . 05 G YELLOWSTONE NATIONAL PARK IV 05 KM 3.0 ML(A) DEC 19 17 10 15. 6 44,,77 110 . 80 G YELLOWSTONE NATIONAL PARK VI 05 KM 4.9 MB* 4.5 ML DEC 20 01 34 16. 7 44.,84 110 . 83 G YELLOWSTONE NATIONAL PARK IV 05 KM 4.4 MB* 4.3 ML

SEE FOOTNOTES AT END OF TABLE TABLE 1. SUMMARY OF EARTHQUAKES FELT IN U.S. FOR 1976 - CONTINUED

Abbreviations used in source and magnitude columns: (A) U.S. Energy Research and Development Administration (B) University of California, Berkeley C) University of Connecticut, Groton D) University of Montana, Missoula E) California Dept. of Water Resources, Sacramento .F) USGS Open-File Report 77-181 (Fuis and others, 1977) (6) U.S. Geological Survey, National Earthquake Information Service, Golden, Colo. (H) U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park 'I) Dept. of Natural Resources, Bloomington, Ind. J) Weston Observatory, Weston, Mass. L) Lamont-Doherty Geological Observatory, Palisades, N.Y. (M) NOAA, Alaska Tsunami Warning Center, Palmer (0) Seismological Service of Canada, Ottawa (P) California Institute of Technology, Pasadena (S) St. Louis University, St. Louis, Mo. (T) University of Oklahoma, Leonard (U) University of Utah, Salt Lake City (V) Virginia Polytechnic Institute and State University, Blacksburg (W) University of Washington, Seattle (X) University of West Virginia, Morgantown. NOTE: Dates and origin times are listed in Universal Coordinated Time QJTCl, giving the hour, minute, and second. Epicenters are shown in decimal degrees. Only earthquakes with intensity data are listed. See page 3 for a description of magnitudes used in this table. Miscellaneous Activities

HORIZONTAL CONTROL SURVEYS for the 1959-76 period is approximately twice the corresponding standard deviation. This means the FOR CRUSTAL MOVEMENT STUDIES1 uplift should be regarded as a real phenomenon. (See Holdahl, 1977, for additional information.) Results of the 1975 trilateration survey at the expanded RANCH - TEJON site, which spans the TSUNAMIS2 Gar lock fault zone, indicate that left-lateral movement continues and that the accumulated annual Four tsunamis were reported to the National rate is about 5 to 8 mm. The 1975 leveling survey Oceanic and Atmospheric Administration during shows that accumulated uplift at the RANCH net 1976, including one that was recorded on National ranged between 4.1 mm and 22.9 mm relative to the Ocean Survey tide gages. TEJON net during the interval 1971-75. Since 1971, vertical movement has accumulated to 22.9 mm An earthquake on January 14 (mag. 8.0 MS) in at TUNNEL 3 PT 3 and to 17.3 mm at RANCH F. the Kermadec Islands (28.4°S, 177.7°W) caused a minor tsunami that was recorded as far away as Leveling results show that: MEADE B subsided Hawaii. The Australian Domestic Service reported about 0.6 m between 1972 and 1975 and shifted a 90-cm wave in the southern Fiji Islands. horizontally about 4 cm since 1969; MEADE A Recorded wave heights include 6 cm at Honolulu; 29 subsided 35 mm and shifted horizontally 17.2 mm cm at Kahului; 14 cm at Apia; and 15 cm at Suva. from 1969 to 1975; and RON RM 3 subsided 11.6 mm. An earthquake on January 21 (mag. 7.0 MS) in The other monuments at the MEADE site have the Kuril Islands (44.9°N, 149.1°E) caused a minor remained stable. local tsunami. The USSR reported tsunami heights of 13 cm at Burevestnik, 12 cm at Malokurilskoye, The fifth and sixth surveys were made in 1973 and 3 to 4 cm at Yuzhno-Kurilsk. and 1975-76 at Site 18 - UNION, along the South San Francisco Bay section of the aqueduct which The destructive Guatemala earthquake (mag. straddles the Hayward fault 11 km southeast of 7.5 MS) of February 4 (15.3°N, 89.1°W) caused a Hayward. Overall observed changes indicate that tsunami that was recorded on the Puerto Cortes right-lateral movement continues at an annual rate tide gage with a maximum amplitude of 45 cm. of 6 to 7 mm. Significant vertical movement was On August 16, an earthquake (mag. 7.9 MS) and not apparent. tsunami killed 5,000 to 8,000 people. The earthquake, located in Mindanao, Philippine The fourth and fifth resurveys at Site 19 - Islands (6.3°N, 124.0°E), caused a major tsunami VERAS, along the South San Francisco Bay section in Moro Gulf. The tsunami reached 400 to 475 cm of the aqueduct which straddles the Calaveras above sea level at Pagadian City, Alicia, Bongo fault, indicate a continuation of right-lateral Island, Resa Bay, Lebak, and the east coasts of movement at an annual rate of 2 to 3 mm and a Basilan and Jolo Islands. The wave was recorded small relative subsidence of approximately 1 mm on the Davao tide gage with a maximum amplitude of annually on the southwest side of the fault. 35 cm.

VERTICAL MOVEMENT STUDIES PRINCIPAL EARTHQUAKES OF THE WORLD Because of the concern about the crustal uplift in the Palmdale area of southern Table 2 lists principal world earthquakes for California, the National Geodetic Survey has 1976» The list has been included in this annual attempted to obtain the best estimates possible of series since 1941. It includes earthquakes of its character, magnitude, and areal extent. magnitude 6.8 or greater; those of smaller magni­ Velocities of elevation change for 1906-62 and tude that were locally destructive to life and 1959-76 were determined from southern California property; and events of unusual interest. leveling data. The study area extends from San Pedro north to latitude 35.5°, and between Nineteen earthquakes of magnitude 6.8 and longitudes 117° and 119.5°. above occurred in 1976. The most destructive oc­ curred in northeastern China on July 27, and The velocity surface for the 1906-62 period killed over 655,000 people. This is the second shows negligible subsidence of 1 mm/yr at largest death toll from an earthquake in recorded Palmdale, increasing to 9 mm/yr at Bakersfield. history. The largest toll--830,000 fatalities-­ The 11 mm/yr maximum uplift velocity determined resulted from a 1556 earthquake in China.

Prepared by John G. Gergen, NOAA, National Ocean Survey, National Geodetic Survey, Rockville, ^Prepared by Mark G. Spaeth, NOAA, National Md. Weather Service, Silver Spring, Md. 71 FLUCTUATIONS IN Table 3 lists well-water fluctuations caused WELL-WATER LEVELS3 principally by earthquakes. It includes county and (or) well number, date and time at recorder, depth to water before disturbance, and water-level In 1943, the Coast and Geodetic Survey (now fluctuations. Table 4 lists earthquakes believed the National Ocean Survey) first published the to have caused fluctuations in well-water levels section on well-water fluctuations in its annual in 1976. It contains date, time, and hypocenter United States Earthquakes series. Data for the of the earthquake; the states recording fluctua­ years 1944-49appeared in the 1949 issue. From tions; and earthquake magnitude. 1950 to the present, the material has been published annually in this series. Complete information on earthquakes possibly associated with the fluctuations tabulated in table 3 may be obtained from the Preliminary 3 Prepared by Kenneth L. Rennick, U.S. Determination of Epicenters Monthly Listing. Geological Survey, Denver, Colo. published by the USGS.

72 TABLE 2 - PRINCIPAL EARTHQUAKES OF THE HORLD DURING 1976 (SOURCE. PRELIMINARY DETERMINATION OF EPICENTERS MONTHLY LISTING, PUBLISHED BY U.S. GEOLOGICAL SURVEY.!

GEOGRAPHIC USGS OTHER

DATE ORIGIN TIME COORDINATES REGION REMARKS DEPTH MAGNITUDE MAGNITUDE UT LAT LONG H M S OEG. DEG. KM MB MS ML

JAN Hi 15 56 3*t.9 29.2S 177.9M KERMADEC ISLANDS DAMAGE ON RAOUL 069 6.3 7.7PAS

JAN l

JAN 21 10 05 2<».l 44.9N 149.IE KURIL ISLANDS FELT. TSUNAMI REPORTED 041 6.3 7.0 6.4PAS

FEB 0<» 09 01 43.4 15.3N 069.1M GUATEMALA AT LEAST 23,000 KILLED. 005 6.2 7.5 7.5PAS EXTENSIVE DAMAGE

FEB 19 13 59 59.6 19.9N 076.9M CUBA REGION 1 KILLED, 6 INJURED IN 020 5.3 5.9 CAMARON AREA

MAR 13 16 30 41.5 H».6N 091.1H GUATEMALA 4 REPORTED KILLED* 005 5.4 5.1 CONSIDERABLE DAMAGE

MAR 19 13 03 36.4 36.6N 067.6E HINDU KUSH REGION 49 KILLED, HEAVY DAMAGE 033 5.6 5.5

MAR 25 11 55 39.4 41.IN 043.OE TURKEY-USSR BORDER REGION 1 KILLED* 6 INJURED. 016 4.6 SEVERAL VILLAGES FLATTENED IN KARS REGION

APR 02 16 56 07.6 39.8N 043.6E TURKEY l» KILLED* 2 INJURED 046 4.6

APR 06 02 40 27.0 40.3N 063.6E UZBEK SSR DAMAGE IN GAZLI-BUKHARA 033 6.f 7.0 7.1PAS AREA

APR 09 07 08 <»7.0 00.6N 079.6H NEAR COAST OF ECUADOR 8 KILLED, 46 INJURED 009 6.1 6.7 6.3PAS

APR 29 22 16 09.1 <»0.9N 042.9E TURKEY 4 KILLED, MANY HOUSES 044 5.0 5.5 COLLAPSED

MAY 06 20 00 11.6 46.4N 013.3E NORTHEASTERN ITALY 1000 REPORTED KILLED, 009 6.0 6.5 3700 INJURED. EXTENSIVE DAMAGE

MAY 15 21 55 56.5 11.6S 074.5M PERU 5 REPORTED KILLED, 30 033 6.0 6.6 6.5PAS INJURED BY LANDSLIDES

MAY 17 OZ 56 40.6 40.4N 063.5E UZBEK SSR 6 KILLED, 10,000 010 6.3 7.0 7.1PAS HOMELESS IN GAZLI AREA

AUG 17 04 19 Z7.3 07.2N 122.9E MINDANAO, PHILIPPINE ISLANDS DAMAGE AND INJURIES 022 6.2 6.6 5.0PRU AUG 19 01 12 36.7 37.7N 028.9E TURKEY 4 KILLED* 50 INJURED. 003 5.0 4.9 1800 HOMES DESTROYED

SEE FOOTNOTES AT END OF TABLE TABLE 2 - PRINCIPAL EARTHQUAKES OF THE WORLD DURING 1976 - CONTINUED

GEOGRAPHIC USGS OTHER

DATE ORIGIN TIHE COORDINATES REGION REMARKS DEPTH MAGNITUDE MAGNITUDE

UT LAT LONG H H S DEC. OEG. KH MB MS ML

HAY 29 12 23 16.7 24.6N 099.OE YUNNAN PROVINCE, CHINA CASUALTIES AND 008 6.1 6.9 6.9BRK EXTENSIVE DAMAGE

NAY 29 14 00 18.5 24.5N 098.7E BURMA-CHINA BORDER REGION CASUALTIES AND 010 6.0 7.0 6.9PAS EXTENSIVE DAMAGE

JUN 20 20 53 13.4 03.«»N 096.3E NORTHERN SUNATRA FELT 033 6.3 7.0 7.0PAS

JUN 25 19 18 56.9 0«».6S 1*0. IE WEST NEH GUINEA 422 REPORTED KILLED, 033 6.1 7.1 7.1PAS 5000-9000 MISSING IN LANDSLIDES. 6 VILLAGES REPORTED DESTROYED

JUL 09 09 3% 42.7 38.3N 0*0.5E TURKEY I KILLED, 2 INJURED 033 4.2

JUL 11 20 111 47.5 07.4N 078.1M PANAMA 7 INJURED, DAMAGE 003 6.2 7.0 7.0PAS

JUL l

JUL 27 19 42 54.6 39.6N 116. OE NORTHEASTERN CHINA 655,237 REPORTED KILLED, 023 6.3 7.9 7.6PAS AROUND 800,000 INJURED. DEATH TOLL PROBABLY THE SECOND GREATEST FROM AN EARTHQUAKE IN RECORDED HISTORY. EXTENSIVE DAMAGE OVER A HIDE AREA

JUL 28 10

AUG 02 10 55 25.7 20.6S 169.3E NEH HEBRIDES ISLANDS FELT 052 6.1 6.9 7.0PAS

AUG 16 14 06 45.9 32.8N 104. 2E SZECHHAN PROVINCE, CHINA PROBABLE CASUALTIES AND 016 6.1 6.9 DAMAGE

AUG 16 16 11 07.3 06.3N 124.OE MINDANAO, PHILIPPINE ISLANDS 5000-8000 REPORTED 033 6.4 7.9 7.9BRK KILLED. TSUNAMI, EXTENSIVE DAMAGE

SEP 11 16 31 21.0 46.3N 013.2E NORTHEASTERN ITALY AT LEAST 5 KILLED, 016 5,2 5.5 CONSIDERABLE DAMAGE

SEP 15 03 15 19.9 46.3N 013.2E do. II REPORTED KILLED, 010 5.7 6.0 6.3CLL CONSIDERABLE DAMAGE

ccc rfwrMrrrrc AT rwn nr TflRi F TABLE 2 - PRINCIPAL EARTHQUAKES OF THE WORLD DURING 1976 - CONTINUED

GEOGRAPHIC USGS OTHER DATE ORIGIN TIHE COORDINATES REGION REMARKS DEPTH MAGNITUDE MAGNITUDE UT LAT LONG H M S DEG. OEG. KH MB HS HL

OCT 06 09 12 38.9 00. 7S 078. BH ECUADOR 9 KILLED, MANY HOMELESS 033 5.7 OCT 29 02 51 07.6 0«».5S 139. 9E WEST NEW GUINEA 133 REPORTED KILLED 033 6.1 7.1 7.2PAS NOV 07 Ok 00 51.6 33. 8N 059. 2E IRAN 17 KILLED, 32 INJURED. 013 5.6 6.2 HEAVY DAHAGE NOV 07 17 09 06.1 08. 5N 126. <»E MINDANAO, PHILIPPINE ISLANDS DAMAGE REPORTED 060 6.0 6.8 6.9PAS NOV Zk 12 22 18.6 39. IN 0<»«». OE N.H. IRAN-USSR BORDER REGION ESTIMATED 5000 DEATHS, 036 6.1 7.3 7.3PAS EXTENSIVE DAHAGE IN TURKEY AND IRAN NOV 30 00 40 57.8 20. 5S 068. 9M CHILE-BOLIVIA BORDER REGION 1 KILLED, 13 INJURED. 082 6.5 CONSIDERABLE DAMAGE TO HOMES

DEC OS 08 38 25.7 28. OS 026. 7E REPUBLIC OF SOUTH AFRICA «» KILLED, 36 INJURED. 033 5.2 CONSIDERABLE DAMAGE

Abbreviations used in magnitude column: BRK University of California, Berkeley; CLL Collmberg, German Democratic Republic; PAS California Institute of Technology, Pasadena; PRU Pruhonice, Czechoslovakia. NOTE: See page 3 for a description of magnitudes used in this table. TABLE 3 - EARTHQUAKE FLUCTUATIONS IN WELL-WATER LEVELS DURING 1976

DATE/TIME DEPTH HATER-LEVEL FLUCTUATIONS AT TO HATER COUNTY AND/OR RECORDER BEFORE FROM PREQUAKE LEVEL DOUBLE HELL NUMBER U.T. DISTURBANCE UPHARO DOHNHARO AMPLITUDE (HI (CM) (CM) (CM)

ALASKA

AK JUL 27, 1930 2.** 1.22 3.66 AK 20*9 JUL 28, 1130 1*.23 0.61 1.22 1.83

GEORGIA

DECATUR 9F520 FEB o*. 0900 13. *1 9.1* 18.29 LONG 33M* FEB o<», 0900 13.17 *.27 3.35 7.62 HAYNE 3OKI* FEB 0<», 0900 6.«*<* 2.7% 2.7* 5.1*9 DOUGHERTY 13L3 FEB 0*, 0905 10.80 9.*5 10.97 20.1*2 DOUGHERTY 0019 FEB o<». 0905 18.«*0 6.10 5.16 11.28 OOUGHERTY 13L3 JUL 11, 1735 9.63 1.52 1.83 3.35 CHARLTON 27E2 JUL 27, 1950 20.06 0.61 1.52 2.13 DOUGHERTY 13L3 JUL 27, 1950 9.63 1.52 1.83 3.35 DOUGHERTY 0019 JUL 27, 1950 19.05 2.13 1.22 3.35 LONG 33M* JUL 27, 2015 13.80 1.52 0.91 2.1*4 MCINTOSH 35M13 JUL 27, 2015 *.*5 0.91 1.22 2.13 HAYNE 31L1 JUL 27, 2015 6.65 0.61 0.30 0.91 OOUGHERTY 13L3 JUL 28, 1115 9.65 0.91 0.91 1.83 DOUGHERTY 0019 JUL 28, 1115 19.07 0.30 0.61 0.91 HAYNE 30K<» AUG 16, 7.39 0.61 0.61 1.22 OOUGHERTY 13L3 AUG 16, 1655 9.97 1.22 1.52 2.7* CHARLTON 27E2 AUG 16, 1700 20.35 0.91 1.22 2.13 LONG 33M* AUG 16, 1700 1<».09 0.61 0.61 1.22 HAYNE 31L1 AUG 16, 1700 6.88 0.91 0.91 1.83 MCINTOSH 35M13 AUG 16, 1710 0.61 0.91 1.52

IDAHO

8UTTE i»N-30E-7ADBl JAN 11*, 1600 96.65 1.22 1.83 3.05 8UTTE *N-30£-7ADB1 JAN 11*, 1700 96.65 2. 7«i 3.05 5.79 8UTTE 3N-29E-li»ADBl JAN 11*, 1800 137.67 0.91 0.61 1.52 3UTTE 3N-29E-1*AOB1 FEB 01*, 0915 137.52 1.22 2.7* 3.96 9UTTE i»N-30£-7ADBl FEB Ot», 0915 96.55 3.35 *.27 7.62 8LAINE 1S-19E-3CCB2 FEB 01*, 09*5 5.00 0.61 0.30 0.91 CASSIA 13S-21E-18BBC1 FEB Qt», 09«*5 171.1*9 0.91 2.1*1* 3.35 BUTTE *N-30E-7AOB1 FEB 09, 2120 96.55 0.61 0.61 1.22 9UTTE 3N-29E-li»ADBl FEB 09, 2130 137.53 0.91 0.61 1.52 CASSIA 13S-21E-18BBC1 MAY 02, 0800 170.99 2. 7* I*.88 7.62 3UTTE *N-30E-7ADB1 JUN 07, 1515 96.61* 2.it«* 3.05 5.1*9 TABLE 3 - EARTHQUAKE FLUCTUATIONS IN WELL-WATER LEVELS DURING 1976 - CONTINUED

DATE/TIME DEPTH HATER-LEVEL FLUCTUATIONS AT TO MATER COUNTY ANO/OR RECORDER BEFORE FROM PREQUAKE LEVEL DOUBLE HELL NUMBER U.T. DISTURBANCE UPHARD DOHNHARO AMPLITUDE (Ml (CM) (CM! fCMI

IDAHO

(CONTINUED)

BUTTE 3N-28E-l

INDIANA

HA 32 JAN 03, 1815-1820 2.96 0.61 0.30 0.91 HA 32 JAN 13. 1250-1305 2.99 0.91 0.30 1.22 SH 2 JAN l«f, 0950-1005 5.80 0.00 0.61 0.61 HA 32 JAN l«f, 161*0-1820 3.00 3.39 1.22 *.57 HA 32 JAN 21, 1050-1110 2.98 0.30 0.30 0.61 HA 32 FEB Ot. 1010-10.88 HA 32 JUL 27, 1930-2015 3.55 3.66 2.<»* 6.10 MA 32 AUG 16, 1610-16

NEVADA

S17/50-360C1 JAN 03, 1930 0.91 7.32 8.23 S17/50-360C1 JAN 08, 1630 0.91 0.91 0.00 0.91 S17/50-360C1 JAN 10, 0930 0.90 0.30 0.91 1.22 S17/50-36DC1 JAN lit, 1630 0.91 3.05 5.79 8.8<> S17/50-360C1 FEB 01, 1115 0.83 0.91 0.30 1.22 TABLE 3 - EARTHQUAKE FLUCTUATIONS IN WELL-WATER LEVELS DURING 1976 - CONTINUED

DATE/TIME DEPTH HATER-LEVEL FLUCTUATIONS AT TO HATER COUNTY ANO/OR RECORDER BEFORE FROM PREQUAKE LEVEL DOUBLE HELL NUMBER U.T. DISTURBANCE UPWARD DOWNWARD AMPLITUDE (M) (CM! (CMI fCM)

NEVADA (CONTINUEDI

S17/50- 360C1 FEB 12, 1630 0.82 (».88 9.75 <».63 S17/50- 360C1 FEB id, 131*5 0.80 2.7* 2.71. 5.<»9 S 17/50- 360C1 FEB 23, 1550 0.82 0.61 0.61 1.22 S17/50- 360C1 FEB 35, 2315 0.82 0.30 0.61 0.91 S17/50- 360C1 MAR 09, 1«»15 0.80 3.66 «».57 8.23 S17/50- 360C1 MAR 29, 05i»5 0.87 0.91 1.22 2.13 S17/50- 360C1 JUN 06, 0300 0.91* 0.91 0.61 1.52 S17/50- 360C1 JUN 07, 1500 0.97 2.7i» 3.35 6.10 S17/50- 360C1 JUL 11, 1630 0.92 0.30 1.52 1.83 S17/50- 360C1 JUL 11, 20<»5 0.93 2.<»<» 0.61 3.05 S17/50- 360C1 JUL 27, 2015 0.92 if. 88 3.96 8.81* S17/50- 360C1 JUL 28, 1120 0.85 1.52 1.52 3.05 S17/50- 360C1 AUG 05, 1800 0.89 0.91 0.00 0.91 S17/50- 36DC1 AUG 16, 1620 0.87 3.96 3.35 7.32 517/50- 360C1 AUG 26, 1<»00 0.83 3.35 3.66 7.01 517/50- 360C1 SEP 26, 21«»5 0.83 0.61 0.00 0.61 S17/50- 360C1 OCT 11, 2350 0.85 1.22 0.91 2.13 S17/50- 360C1 OCT 29, 0315 0.87 0.61 0.61 1.22 S17/50- 36DC1 NOV 0<», 10<»5 0.85 0.91 0.30 1.22 S17/50- 360C1 DEC 07, 1315 0.83 1.22 0.91 2.13 S17/50- 360C1 DEC 08, 1<»50 0.81 0.30 0.00 0.30 S17/50- 360C1 DEC 09, 1000 0.8<» 1.22 0.91 2.13 S17/50- 36DC1 DEC 11, 2315 0.8i» 0.30 0.30 0.61 S17/50- 360C1 DEC 20, 2030 0.81* 2.13 3.05 5.18 S17/50- 360C1 DEC 23, 0930 0.87 1.83 1.22 3.05 S17/50- 360C1 DEC 28, 1755 0.83 2.7«» 2.7«» 5.1*9

HISCONSIN

LF-57 JAN 03, 1850 29.95 0.61 0.30 0.91 MI-120 JAN 03, 1935 22.i»69 0.000 0.21*1* 0.21*1* LF-57 JAN 13, 1330 29.90 0.61 0.61 1.22 LF-57 JAN 1<», 1605 30.05 5.1*9 2.1*1* 7.92 MI-120 JAN 1<», 1705 22.50<» 2.682 1.829 i*.511 MI-120 JAN 21, 1050 22.<*0 0.61*0 0.2i»i> 0.881* LF-57 JAN 21, 1100 29.98 0.61 1.22 1.83 LF-57 FEB Oi», 0900 30.10 7.32 7.01 i».33 MI-120 FEB 0<», 0915 22.1*22 3.109 3.871 6.980 ON-H*3 FEB Oi»t 0930 15.50 0.30 0.30 0.61 MI-120 FEB 23, 1500 22.1*1*8 0.335 0.1*27 0.762 IT & cw « » CNJ us

oO a.-JO *» ocMeoooovHrorotccMMnoiririrvtto^ocMi-icMUN X CM wi

I Z O I X » o

00 >irt^,4 CM e UN to ** «o *4 ^ ^ ^ «o w ?? <^*0T*T*u>r*^^*?? (W i?^'

UN«C(T o CD «> M uj a* u. « r v> 3 uiz ui D *» z z O (OH O M o v> o »- fOCM MCMCVJ TCP) CMCMrOMCMCMCMO H M 10 Z O MO

M UJ »- O . *>>t~ 0£t- Ul< O I- O 3 < UI O Of

O Of ^ UJ O CD Z Z

ee e ee UN UN o o UN UN o o oeee N I I I I I I

79 TABLE * - EARTHQUAKES IN 1976 BELIEVED TO HAVE CAUSED FLUCTUATIONS IN HELL-MATER LEVELS

GEOGRAPHIC USGS OTHER DATE ORIGIN TIME COORDINATES REGION IEPTH MAGNITUDE MAGNITUDE UT LAT LONG H M S DEG . DEG. KM MB MS ML JAN 03 19 15 00. 2 37. 2N 116. 3W SOUTHERN NEVADA INDIANA, NEVADA, 000 6.2 5.5 6.3BRK HISCONSIN. JAN 08 16 14 19. 9 37. 3N 116. 3W SOUTHERN NEVADA NEVADA. 005 4.5 4.3BRK

JAN 10 06 58 45. 2 43. 5N 127. 4W OFF COAST OF OREGON NEVADA. 033 5.% JAN 13 13 29 19. 5 66. IN 016. 5W ICELAND REGION INDIANA, WISCONSIN. 033 6.0 6.4 6.4PAS JAN 14 06 28 07. 4 29. 2S 177. 2H KERMADEC ISLANDS INDIANA. 064 5.3 JAN 14 15 56 34. 9 29. 2S 177. 6W KERMADEC ISLANDS IDAHO, WISCONSIN. 069 6.3 7.7PAS JAN 1% 16 47 33. 5 28. 4S 177. 6W KERMAOEC ISLANDS REGION IDAHO, INDIANA, NEVADA. 033 6.5 a. o 6.0PAS JAN 21 10 05 24. 1 44. 9N 149. IE KURIL ISLANDS INDIANA, WISCONSIN. 041 6.3 7.0 6.4PAS FEB 01 11 14 57. 3 17, IN 100. 1W GUERRERO, MEXICO NEVADA. 052 5.7 5.6 5.6PAS FEB 04 09 01 43. » 15. 3N 069. 1W GUATEMALA GEORGIA, IDAHO, INDIANA, 005 6.2 7.5 7.5PAS WISCONSIN. FEB 04 09 30 29. - 14. 9N 090. 5N GUATEMALA IDAHO* INDIANA, NEVADA, 005 5.4 WISCONSIN. FEB 09 21 29 57. 1 21. 5N 106. 6M OFF COAST OF CENTRAL MEXICO IDAHO. 046 5.5 5.4

FEB 12 17 37 29. 0 37. 2N 116. 4W SOUTHERN NEVADA NEVADA. 000 4.8 4.3BRK FEB 23 15 14 16. 0 51. 4N 130. 4W QUEEN CHARLOTTE ISLANDS REGION NEVADA, HISCONSIN. 016 5.6 6.0 5.6PAS MAR 09 14 00 00. 1 37. 3N 116. 3W SOUTHERN NEVADA NEVADA. 000 6.0 4.8 5.9BRK MAR 1* 12 30 00. 2 37. 3N 116. 4W SOUTHERN NEVADA WISCONSIN. 000 6.3 5.3 6.2BRK MAR 29 05 39 35. 5 03. 9N 065. 8W OFF COAST OF CENTRAL AMERICA NEVADA, INDIANA. 033 5.9 6.5 6.5PAS APR 09 07 06 47. 0 00. 7N 079. 8H NEAR COAST OF ECUADOR WISCONSIN. 009 6.1 6.7 6. SPAS MAY 02 08 23 03. 9 34. 3N 117. OH SOUTHERN CALIFORNIA IDAHO. 006 3.0 3.0PAS MAY 15 21 55 58. 5 11. 6S 074. 4W PERU INDIANA. 033 6.0 6.6 6.5PAS MAY 17 02 58 40. 6 40. 3N 063. 4E UZBEK SSR INDIANA, WISCONSIN. 010 6.3 7.0 7.1PAS

SEE FOOTNOTES AT END OF TABLE TABLE l» - EARTHQUAKES IN 1976 BELIEVED TO HAVE CAUSED FLUCTUATIONS IN HELL-HATER LEVELS - CONTINUED

GEOGRAPHIC uses OTHER

DATE ORIGIN TIHE COORDINATES REGION STATES RECORDING FLUCTUATIONS DEPTH MAGNITUDE MAGNITUDE UT LAT LONG H N S OEG. OEG. KM MB MS ML NAY 29 14 00 18.5 24.5N 098.7E BURMA-CHINA BORDER REGION WISCONSIN. 010 6.0 7.0 6.9PAS JUN 06 02 35 31.6 49.IN 127.7M VANCOUVER ISLAND REGION NEVADA. 033 >».5 JUN 07 14 26 39.1 17.dN 100.6M 6UERRERO, MEXICO IDAHO, NEVADA, WISCONSIN. 045 6.1 6.% 6.7PAS JUN 20 20 53 13.4 03.3N 096.3E NORTHERN SUMATRA WISCONSIN. 033 6.3 7.0 7.0PAS JUN 25 19 18 56.9 04.6S 140.OE WEST NEM GUINEA WISCONSIN. 033 6.1 7.1 7.1PAS JUL 11 16 54 31.8 07.3N 078.4W PANAMA GEORGIA. IDAHO, 022 6.3 6.7 6.6PAS INDIANA, NEVADA, WISCONSIN. JUL 11 20 41 47.5 07.4N 078.1M PANAMA INDIANA, NEVADA, 003 6.2 7.0 7.0PAS WISCONSIN. JUL 27 19 <»2 54.6 39.5N 117.9E NORTHEASTERN CHINA ARKANSAS, GEORGIA, 023 6.3 7,9 7.6PAS IDAHO, INDIANA, . NEVADA, WISCONSIN.

JUL 28 10 45 35.2 39.6N 116.dE NORTHEASTERN CHINA ARKANSAS, GEORGIA, IDAHO, 026 6.3 7.1PAS NEVADA, WISCONSIN.

AUG 05 17 36 37.9 45.6N 112.4W MONTANA NEVADA. 005 2.9ERD

AUG 16 16 11 07.3 06.2N 12%.OE MINDANAO* PHILIPPINE ISLANDS GEORGIA, IDAHO, 033 6.% 7.9 7.9BRK INDIANA, NEVADA, WISCONSIN. AUG 26 14 30 00.2 37.IN 116.OH SOUTHERN NEVADA NEVADA. 000 5.3 4.2 5.1BRK

SEP 26 22 44 37.2 39.3N 118.1M NEVADA NEVADA. 005 3.0 OCT 12 00 40 52.9 10.4S 161. 2E SOLOMON ISLANDS NEVADA. 106 6.0 6.4PAS OCT 29 02 51 07.6 04.5S 139.9E WEST NEM GUINEA NEVADA. 033 6.1 7.1 7.2PAS NOV 0<» 10 41 37.5 33.IN 115.5H SOUTHERN CALIFORNIA NEVADA. 00% 4.6 5.3 4.9PAS NOV 18 03 24 00.2 08.85 156.9E SOLOMON ISLANDS INDIANA. 033 6.1 6.5 6.6PAS NOV 2% 12 22 18.8 39.IN 044.OE N.M. IRAN-USSR BORDER REGION WISCONSIN. 036 6.1 7.3 7.3PAS

SEE FOOTNOTES AT END OF TABLE TABLE

GEOGRAPHIC USGS OTHER DATE ORIGIN TIME COORDINATES REGION STATES RECORDING FLJCTUATIONS DEPTH MAGNITUDE MAGNITUDE UT LAT LONG H M S DEC. DEG. KM MB MS ML NOV 26 11 19 25.2 <»1.2N 125. 7W OFF COAST OF NORTHERN CALIFORNIA IDAHO* WISCONSIN. 015 6 .0 6.8 6.2BRK DEC 07 12 59 56.3 31. 9N ll

DEC 28 18 00 00.1 37. IN 116. OW SOUTHERN NEVADA NEVADA. 000 5 .5 5.5BRK

Abbreviations used in magnitude column: BRK -- University of California, Berkeley; ERD -- U.S. Energy Research and Development Administration; PAS California Institute of Technology, Pasadena. NOTE: See page 3 for a description of magnitudes used in this table. Strong-Motion Seismograph Data1

INTRODUCTION publication dates and detailed information on the availability of digitized data, is published The U.S. Geological Survey Seismic Engineer­ regularly in the Seismic Engineering Program ing Branch (formerly the National Oceanic and Report. Atmospheric Administration Seismological Field Survey) has administered engineering seismology programs in the United States and Latin America since 1932. The current strong-motion The Strong-Motion Accelerograph Station List. instumentation program is supported by the periodically published as a USGS Open-File Report, National Science Foundation (Grant CA-114) in includes information on all accelerograph stations cooperation with both private industry and known to USGS in the Western Hemisphere. Because educational institutions, as well as numerous this information is always changing, it is Federal, state, and local agencies. The program impossible to have a complete list of all existing objectives are to: (1) record strong ground stations at any one time. Rather, the list motions and the response of representative types provides that community of persons interested in of structures during potentially damaging strong-motion programs with a reasonably complete earthquakes, and (2) disseminate processed data indication of the current status of the various and information about records, sites, and strong-motion networks. Information in this structures to users in earthquake engineering station list includes the station name and (or) research and design practice. These data are address and geographic coordinates, site disseminated in various ways. characteristics, type and size of structure, location of instrument(s), and primary data USGS publishes preliminary earthquake reports sources. The current list contains information on and a summary of recent accelerograph records in approximately 1,200 stations located in 38 states, the quarterly Seismic Engineering Program ReportReport'2 , Canada, the Caribbean, and throughout Central and These summaries include a brief descriptionDn of thetli South America. earthquakes and strong-motion recording stations, results of routine seal ings of records that contain peak accelerations greater than 0.05 £, and photographic reproductions of some of the significant accelerograms. They also contain ACCELEROGRAPH DATA abstracts of recent technical reports, notes on strong-motion information sources, remarks about the availability of digitized data, and other Ninety accelerograph records were recovered from the National Strong-Motion Network from information pertinent to the U.S. strong-motion program. January through December 1976. The yearly average from 1972 through 1975 was 218 records.

USGS periodically publishes Strong-Motion Table 5 lists accelerograph records that were Data Reports in the Open-File Report series. recovered, although not necessarily recorded, These include the results of digitization and during 1976. The earthquakes are listed in routine analyses of strong-motion accelerograms chronological order and include date, time (UTC), that contain peak accelerations greater then 0.10 general location, geographic coordinates, and £. This minimum acceleration level is based magnitude. Information about the recording primarily on the current capability of USGS to station includes the name and location, owner, and process strong-motion records; it may vary with geographic coordinates. Record data include both the degree of seismic activity and the number S-wave minus trigger time (S-t), and the of personnel available at any given time. orientation, maximum acceleration, and duration of Although maximum acceleration is not directly strong motion (greater than 0.10 $) for each related to frequency or duration of strong motion, instrument component. Record data are included the peak acceleration can be readily obtained from only if one or more components recorded at least an accelerogram. Thus that value is used as an 0.05 $ at ground stations or 0.10 £ at upper indicator of the potential significance of the floors of buildings. Table 6, a summary of record. A list of the records to be contained in non-U.S. accelerograph records obtained in 1976, future data reports, including estimates of their contains the same type of information and data as table 5. The event information has been compiled principally from the Preliminary Determination of 1 Prepared by Ronald L. Porcella, Seismic Epicenters Monthly Listing, published by USGS. Engineering Branch, U.S. Geological Survey, 345 Middlefield Road, Mail Stop 78, Menlo Park, California 94025. The following paragraphs summarize the 2 Copies of these reports are available from results of the most significant earthquakes from address given in footnote 1. which strong-motion records were obtained in 1976. 83 SOUTHERN CALIFORNIA - JANUARY 1 shock, which was reported felt over a seven-state region, triggered seven accelerographs located at This magnitude 4.2 earthquake occurred 1n the four stations. Four strong-motion records were Puente Hills of eastern Los Angeles County, recovered at Arkabutla Dam, Miss., two at approximately 4 km north of the Wh1tt1er fault Wappapello Dam, Mo., one at Tiptonville, Tenn., zone at a depth of about 6 km. Eleven and one at New Madrid, Mo. The maximum recorded strong-motion records were recovered within a acceleration was 0.04 3 (Risavich and Porcella, 14-km radius of the epicenter; nine of these 1976). The toe station at Arkabutla Dam produced display peak accelerations greater than 0.10

84 TABLE 5. SUMMARY OF U.S. ACCELEROGRAPK RECORDS RECOVERED DURING 1976

EVENT STATION- STATION S-T TIME2 COMP MAX ACCL^ DURATION4 (OWNERr COORD. (SEC) (G) (SEC)

30 November 1975- Kilauea, Hawaii 19.43 N. S30W 0.05 _ 22 March 1976 Namakani Paio 155.30 W Down 0.03 - Kllauea, Hawaii (USGS) S60E 0.05 - Epicenters and Kilauea, Hawaii - magnitudes unknown 19.43 N S30W 0.06 Namakani Paio 155.30 W Down 0.03 (USGS) S60E 0,05 - Kilauea, Hawaii 19.43 N S30W 0.04 - Namakani Paio 155.30 W Down 0.04 - (USGS) S60E 0.06 -

10 December 1975 El Centre station 5 32.85 N 3.3 ** 0958 UTC 2801 James Road 115.46 W Imperial Valley (CIT) 32.95N, 115. SOW El Centre station 6 ** Magnitude 3.8 32.84 N 3.4 551 Huston Road 115.49 W (CDMG)

1 January 1976 Brea Dam 33.89 N - 1720 UTC Fullerton, Calif. 117.93 W So. California (USAE) 33.97N, 117.88W Crest station - Magnitude 4.2 2.1 N50W 0.09 Down 0.06 S40W 0.13 0.2 Downstream station 1.8 N50W 0,10 1-peak Down 0.06 - S40W 0.06 - Left abutment station -instrument was i nope rat ive- Carbon Canyon Dam 33.92 N Brea, Calif. 117.84 W (USAE) Crest station 1.7 N50W 0.08 . Down 0.05 _ S40W 0.12 0,5 Right abutment 1.7 N50W 0,10 1-peak station Down 0.04 - S40W 0,14 0.3 Left abutment 1.7 N50W 0.13 1-peak station Down 0.06 - S40W 0.14 0.2

See footnotes at end of table

85 TABLE 5. SUMMARY OF U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976 - CONTINUED

EVENT STATION- STATION S-T TIME2 COMP MAX ACCI/ DURATION4 (OWNER) 1 COORD. (SEC) (6) (SEC) 1 January (cont.) Diemer Filter Plant 33.91 N Yorba Linda, Calif. 117.82 W (MWD)

Administration bldg 1 .6 S79E 0.02 Down 0.03 N11E 0.02 Reservoir 1.7 N79E 0.03 Down 0.03 N11W 0.07 Orange Co. Reservoir 33.94 N Brea, Calif. 117.88 W (MWD) Abutment station 1 .5 N84W 0.18 0.1 Down 0.06 S06W 0.08 Whittier, Calif. 33.97 N 7215 Bright Avenue 118.04 W (CWH) Basement level 2.5 North 0.06 Down 0.07 West 0.17 0.2 5th-floor level 2.5 North 0.07 Down 0.10 0.1 West 0.28 0.6 lOth-floor level 2.5 North 0.04 Down 0.12 0.3 West 0.19 0.7

4 February 1976 Prescott, Ariz. 34.55 N _ ** 0004 UTC VA Hospital 112.45 W Western Arizona (VA) 34.66N, 112. SOW Magnitude 5.2

5 February 1976 Seward, Alaska 60.11 N _ ** 0936 UTC Wesleyan Hospital 149.44 W Alaska (USGS) 59.99N, 149.35W Magnitude 4.8

See footnotes at end of table

86 TABLE 5. SUMMARY OF U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976 - CONTINUED

4 EVENT STATION- STATION S-T TIME2 COMP MAX AGO/ DURATION (OWNERr COORD. (SEC) (i) (SEC)

22 February 1976 Adak, Alaska 51.88 N North 0,03 0721 UTC Seismic vault 176.58 W Down 0.01 - Aleutian Is. (USGS) West Oo05 51.73N, 176. 87W Magnitude 5. 0

25 March 1976 Arkabutla Dam 34.76 N 0041 UTC Arkabutla, Miss e 90.12 W NE Arkansas (USAE) 35.59N, 90.48W ** Magnitude 5.0 Left crest station Left toe station ** Right abutment station ** Wappapello Dam 36.93 N Poplar Bluff, Mo 0 90,27 W (USAE) Right crest station ** Right toe station ** New Madrid, Mo. 36.51 N ** Noranda plant 89.57 W (USGS) Tiptonville, Tenn. 36.37 N ** Reel foot Lake 89.41 W (USGS) 25 March 1976 Arkabutla Dam 34 e 76 N 0100 UTC Arkabutla, Miss. 90.12 W NE Arkansas (USAE) 35.61N, 90.48W ** Magnitude 4.5 Left toe station 8 April 1976 Santa Felicia Dam 34.46 N 1521 UTC Piru, Calif. 118.75 W So 0 California (UWCD) 34.35N, 118.67W Crest station S78W 0.05 Magnitude 4.7 Down 0003 S12E 0.05 Right abutment S78W 0004 station Down 0.03 S12E 0.05

See footnotes at end of table

87 TABLE 5. SUMMARY OF U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976 - CONTINUED

EVENT STATION., STATION S-T TIME2 COMP MAX ACCL 3 DURATION4 (OWNER) 2 COORD. (SEC) (£) (SEC)

14 April 1976 El Centre station 5 32.85 N 2.20 ** 0656 UTC 2801 James Road 115.46 W Imperial Valley (USGS) 32.87N, 115. 48W Magnitude 3.8

14 April 1976 El Centro station 5 32.85 N 2.50* ** 0656 UTC 2801 James Road 115.46 W Imperial Valley (USGS) 32.88N, 115. 53W Magnitude unknown

14 April 1976 El Centro station 5 32.85 N 2.25 N50E 0.07 1031 UTC 2801 James Road 115.46 W Down - Imperial Valley (USGS) N40W 0.06 32.88N, 115. 48W El Centro station 6 Magnitude 3.9 32.84 N 2.20 N50E 0.14 (1-peak) 551 Huston Road 115.49 W Down 0.05 (CDMG) N40W 0.09

26 April 1976 Calipatria 33.13 N 2.65 S45E 0.07 0646 UTC Fire station 115.52 W Down 0.03 Imperial Valley (CIT) N45E 0.05 33.13N, 115. 67W Sal ton Sea Magnitude 3.8 33.18 N 2.05 S45E 0.07 Wildlife refuge 115.62 W Down 0.05 (CIT) N45E 0.08

4 June 1976- Livermore, Calif. 37.62 N _ ** 9 September 1976 VA Hospital 121.76 W Livermore, Calif. (VA) Epicenter and magnitude unknown

11 August 1976 Puerta La Cruz 33.32 N _ ** 1524 UTC Ground level 116.68 W So. California (CDMG) 33.48N, 116. 52W Sage fire station 33.58 N - ** Magnitude 4.3 Ground level 116.93 W (CDMG)

8 September 1976 Tacoma, Wash. 47.25 N _ ** 0821 UTC City/County bldg. 122.45 W Seattle, Wash. (USGS) 47.38N, 123.08W Magnitude 4.8

See footnotes at end of table

88 TABLE 5. SUMMARY OF U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976 - CONTINUED

EVENT STATION- STATION S-T TIME2 COMP MAX ACCL 5 DURATION^ (OWNERr COORD. (SEC) (6) (SEC) * * 13 September 1976 Ferndale, Calif. 40.58 N 1608 UTC City Hall 124.26 W Cape Mendocino (USGS) 40.20N, 124.39W Magnitude 4.0 * * 17 October 1976 Newhall 34.39 N 0538 UTC Fire Station 118.53 W So. California (CDMG) TA fifi N ** 34.45N, 118.37W *yt o uu ii Lake Hughes 118.46 W Magnitude 4.1 ML(B) Station 4 (CIT)

4 November 1976 Calipatria 33.13 N 2.60 S45E 0.04 _ 0548 UTC Fire station 115.52 W Down 0.02 _ Imperial Valley (CIT) N45E 0.06 - 33.12N, 115.60W Magnitude 4.2 ML(P)

4 November 1976 Calipatria 33.13 N 2.80* S45E 0.05 _ 0548 UTC Fire station 115.52 W Down 0.03 - Imperial Valley (CIT) N45E 0.07 - 33.12N, 115. 60W Magnitude unknown

4 November 1976 Calipatria 33.13 N 2.65 S45E 0.04 _ 0621 UTC Fire station 115.52 W Down 0.02 - Imperial Valley (CIT) N45E 0.05 - 33.08N, 115.60W Magnitude unknown Note: Five additional shocks of the November 4 earthquake swarm were recorded at Calipatria before the instrument ran out of film. Maximum acceleration less than 0.05 £.

4 November 1976 Brawl ey Airport 32.99 N 2.90 S45E 0.11 (1-peak) 1041 UTC Transformer bldg. 115.51 W Down 0.04 _ Imperial Valley (CIT) N45E 0.08 - 33.12N, 115. 59W - Magnitude 4.9 Niland 33.24 N 3.10 West 0.08 Fire station 115.51 W Down 0.07 (CDMG) South 0.07 - Superstition Mtn. 32.96 N 0.90 N45W 0.06 _ Camera site 115.84 W Down 0.02 _ (CIT) S45W 0.03 - Imperial Valley 32.93 N 2.90 ** Parachute test facility 115.70 W (CIT)

See footnotes at end of table

89 TABLE 5. SUMMARY OF U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976 - CONTINUED

EVENT STATION, STATION S-T TIME2 COMP MAX ACCL3 DURATION- (OWNER) 2 COORD. (SEC) (i) (SEC)

4 November (cont. ) El Centre station 9 32.79 N ** (USGS) 115.55 W Imperial County Bldg. 32.79 N - ** 940 Main Street 115.56 W (CDMG) Note: Two additional records were obtained from a nine-channel CR-1 recorder at Imperial County Bldg. Maximum acceleration less than 0.05 £.

4 November 1976 Niland 33.24 N 3.00 1412 UTC Fire station 115.51 W Imperial Valley (CDMG) 33.12N, 115.60W Imperial Valley 32.93 N Magnitude 4.4 Parachute test facility 115.70 W (CIT)

CDMG - California Division of Mines and Geology CIT - California Institute of Technology CWH - City of Whittier MWD - Metropolitan Water District USAE - U.S. Army Corps of Engineers USGS - U.S. Geological Survey UWCD - United Water Conservation District VA - Veterans Administration o S-wave minus trigger time. * denotes S-P interval, that is, the earthquake occurred within the instrumental run-time of a previous event. 'y Unless otherwise noted, maximum acceleration was recorded at ground or basement level ** denotes maximum acceleration is less than 0.05 £ at ground stations or less than 0.10 £ at upper floors of buildings. Duration for which peaks of acceleration exceed 00 10 .

90 TABLE 6. SUMMARY OF NON-U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976

EVENT STATION., STATION S-T TIME2 COMP MAX ACCL 5 DURATION4 (OWNERr COORD. (SEC) (6) (SEC) 16 February 1976- Guatemala 14.96 N - South 0.14 1-peak 20 May 1976 Zacapa station 89.59 W Down 0.05 Guatemala (USGS) East 0.11 1-peak Note: Twelve additional shocks were recorded at Zacapa during this time period. Maximum acceleration less than 0.05 £. 18 February 1976 Guatemala City 14. 64 N South 0 .05 _ 0959 UTC IBM building 90. 51 W Down 0 .10 1-peak Guatemal a (USGS) East 0 .05 - Epicenter and magnitude unknown

20 February 1976 Guatemala City 14. 64 N ** to 20 May 1976 IBM building 90. 51 W Guatemal a (USGS) Epicenters and Note: Two additional records magnitudes unknown recovered at IBM building e Maximum acceleration less than 0.05 £.

21 February 1976 Guatemala 14. 94 N 3.0 South 0 .20 1-peak to 26 May 1976 Chichicastenango 91. 11 W Down 0.06 _ Guatemal a (USGS) East 0 .14 0.2 Epicenters and magnitudes unknown 3.0 South 0.19 0.8 Down 0 .07 East 0 .10 1-peak 3.4 South 0 .11 0.2 Down 0 .04 - East 0 .08 - Note: Three additional shocks were recorded at Chichicastenango. Maximum acceleration less than 0.05 £.

1 March 1976 Chinandega, Nicaragua 12. 62 N N25W 0 .03 _ 2330 UTC Cotton States Chemical 87. 13 W Down 0 .01 _ Managua, Nicaragua (US) S65W 0 .05 _ Epicenter and magnitude unknown

5 May 1976 to Guatemal a 15. 69 N ** 6 May 1976 Puerto Santo Tomas 88. 62 W Guatemala (USGS) Epicenter and magnitude unknown

See footnotes at end of table

91 TABLE 6. SUMMARY OF NON-U.S. ACCELEROGRAPH RECORDS RECOVERED DURING 1976 - CONTINUED

EVENT STATION, STATION S-T TIME2 COMP MAX ACCL 3 DURATION^ (OWNERr COORD. (SEC) (6) (SEC)

11 July 1976 Panama Canal Zone 8.96 N ** 1655 UTC Administration bldg. 79.55 W Panama (USGS) 7.34N, 78.47W Magnitude 6.6

11 July 1976 Panama Canal Zone 8.96 N ** 2042 UTC Administration bldg. 79.55 W Panama (USGS) 7o41N, 78.13W Magnitude 7.0

22 October 1976 Chinandega, Nicaragua 12.62 N ** 0404 UTC Cotton States Chemical 87.13 W Nicaragua (US) 12.55N, 87o85W Magnitude 4.9

1 USGS - U.S. Geological Survey US - Institute for Seismic Investigations 2 S-wave minus trigger time * denotes S-P interval, that is, the earthquake occurred within the instrumental run-time of a previous event. 3 Unless otherwise noted, maximum acceleration was recorded at ground or basement level ** denotes maximum acceleration is less than 0.05 £ at ground stations or less than 0.10 £ at upper floors of buildings. Duration for which peaks of acceleration exceed 0.10 £«,

92 Intensities Observed in States Beyond Epicentral Region

[Note: Number In parentheses indicates the number North Carolina: Felt Kentucky earthquake of of earthquakes occurring on that date.] January 19, V; felt Virginia-North Carolina border earthquake of September 13, IV. Alabama: Felt Arkansas earthquake of March 25, V. Oklahoma: Felt Arkansas earthquake of March 25, Arizona: Felt California earthquake of November II. 4, V; felt New Mexico earthquake of January 5, VI. Oregon: Felt California (off the coast) California: Felt Arizona earthquakes of February earthquake of November 26, IV. 4. IV and December 7, VI. Puerto Rico: Felt Virgin Islands earthquake of Colorado: Felt New Mexico earthquake of January October 15, V. 5. V. Rhode Island: Felt Massachusetts earthquake of Connecticut: Felt Rhode Island earthquake of May 10, IV. March 11, V. South Carolina: Felt Virginia-North Carolina Georgia: Felt Tennessee-Georgia border earthquake border earthquake of September 13, II. of February 4, V. Tennessee: Felt Arkansas earthquakes of March 25, Idaho: Felt Utah earthquake of November 5, IV. VI and September 25, V; felt Kentucky earthquake of January 19, V; felt Missouri earthquake of May Illinois: Felt Arkansas earthquake of March 25, 22, V. V; felt Missouri earthquake of December 13, IV. Texas: Felt Oklahoma earthquakes of April 16, IV Indiana: Felt Arkansas earthquake of March 25, and April 19, IV. II. Utah: Felt New Mexico earthquake of January 5, Kentucky: Felt Arkansas earthquake of March 25, IV. VI. Virginia: Felt Kentucky earthquake of January 19, Massachusetts: Felt Rhode Island earthquake of V. March 11, V. Virgin Islands: Felt Puerto Rico earthquake of Mississippi: Felt Arkansas earthquake of March March 29, II. 25, VI. Washington: Felt California (off the coast) Missouri: Felt Arkansas earthquakes of March 25, earthquake of November 26, II; felt Oregon VI and September 25, IV. earthquake of April 13, V. Montana: Felt Wyoming earthquakes of October 19 West Virginia: Felt Kentucky earthquake of (2), IV, December 8, V, December 9, V, December January 19, V; felt Virginia-North Carolina border 19, VI, and December 20, IV. earthquake of September 13, IV. New Mexico: Felt Texas earthquake of January 25, Wyoming: Felt Montana earthquakes of November 27, IV. IV and December 20, III.

93 References Bath, Markus, 1966: Earthquake energy and Lance, R.J., Fogle, G.H., and Long, L.T., 1977: magnitude, Physics and Chemistry of the Report on the earthquake of December 27, in Earth. 7, Oxford amT New York, Pergamon southern Georgia: Earthquake Notes. 48, no. Press, 115-165. 1-2, 51-56. Couch, R., and Farooqui, R., 1976: Investigations of the Deschutes Valley, Oregon earthquake of Huttli, O.W., 1973: Seismic wave attenuation ana 12 April 1976: Oregon State Univ. Tech. Rept. magnitude relations for eastern North GTR 760915, 89 pp. America, J. Geophys. Res. 78, no. 5, 876-885. Etheredge, E.C., and Nielson, J.D., 1976: Strong-motion results from the Puente Hills, California earthquake of 1 January 1976, Porcella, R.L., U.S. Geological Survey, Menlo Seismic Engineering Program Report. Geol. Park, Calif., 1977 (personal communication). Survey Circ. 736-A, 1-2^ Fuis, G.S., Friedman, M.E., and Hileman, J.A., Porcella, R.L., and Nielson, J.D., 1976: 1977: Preliminary catalog of earthquakes in Preliminary report on the Calipatria, southern California, July 1974-September California earthquake swarm: November 1976, 1976, U.S. Geol. Survey Open-File Report Seismic Engineering Program Report, Geol. 77-181, 107 pp. Survey Circ. 736-D, 1-3. Gutenberg, B.,and Richter, C.F., 1956: Magnitude and energy of earthquakes: Anna!i d^ Richter, C.F., 1958: Elementary Seismology: San Geofisica. 9, no. 1, 1-15. Francisco, CaliTTjW.H. Freeman and Co., Inc., 768 pp. Holdahl, S.R., 1977: Recent elevation change in Risavich, F.A., and Porcella, R.L., 1976: southern California, NOAA Tech. Memo. NOS Preliminary report on the northeast Arkansas MGS-7, National Oceanic and Atmospheric earthquake of March 24, 1976, Seismic Administration, U.S. Department of Commerce, Engineering Program Report, Geol. Survey Washington, D.C., 23 pp. Circ. 736-B, l^FT Knudson, C.F., 1976: Preliminary report on the Guatemala earthquakes of February 1976, Wood, H.O., and Neumann, F., 1931: Modified Seismic Engineering Program Report, Geol. Mercalli Intensity Scale of 1931. Bull, of Survey Circ. 736-A, 2-3. Seismol. Soc. Am., 21, no. 4, 277-283.

94 »U.S. GOVERNMENT PRINTING OFFICE: 1978 - 777-067/1270 REGION NO. 8