GEOLOGICAL SURVEY CIRCULAR 723-B Earthquakes in the United States, April-June 1974 Earthquakes in the United States, April-June 1974 By R. B. Simon, C. W. Stover, and W. J. ~erson G E 0 L 0 G I C A L 5 U R V E Y C I R C U LA R 7 2 3-B 1976 United States Department of the Interior THOMAS S. KLEPPE, Secretary Geological Survey V. E. McKelvey, Director Free on application to Branch of Distribution, U.S. Geological Survey, 1200 South Eads Street, Arlington, VA 22202 CONTENTS Page Introduction . B1 Discussion of tables . 3 Modified Mercalli Intensity (damage) Scale of 1931................................... 10 Acknowledgments . 22 References cited . 23 ILLUSTRATIONS FIGURE 1. "Earthquake Report" form . B2 2. Map showing standard time zones of the conterminous United States. 3 3. Map showing standard time zones of Alaska and Hawaii . 4 4. Map of earthquake epicenters in the conterminous United States for April-June 1974......................................................................... 9 5. Map of earthquake epicenters in Alaska for April-June 1974 . 10 6. Map of earthquake epicenters in Hawaii for April-June 1974 . 11 7. Intensity map for the southern Illinois earthquake of 3 April1974 . 15 8. Tornado map of the Midwestern United States for 3 April1974 . 16 9-13. Isoseismal maps for: 9. Southern Illinois earthquake of 5 June 1974 . 20 10. New Madrid, Mo., earthquake of 13 May 1974 . 20 11. Southern New York earthquake of 7 June 1974 . 21 12. Southern Virginia earthquake of 30 May 1974 . 22 13. Northwestern Washington earthquake of 16 May 1974..................................... 23 TABLES Page TABLE 1. Summary of United States earthquakes for April-June 1974: Alaska ................................................................................. B5 California ............................................................................... 7 California-Off the coast .................................................................. 7 Hawaii ................................................................................. 8 Illinois .................................................................................. 8 Kentucky ............................................................................... 8 .Missouri ................................................................................ 8 Montana ................................................................................ 8 m TABLE 1. Summary of United States earthquakes for April-June 1974-Continued Page Nevada ................................................................................ B8 New York .............................................................................. 8 Oregon-Off the coast ................................................................... 8 Pennsylvania ........................................................................... 8 Utah .................................................................................. 8 Virginia ............................................................................... 8 Washington ............................................................................ 8 Wyoming .............................................................................. 8 2. Summary of macroseismic data for United States earthquakes, April-June 1974: Alaska ................................................................................ 12 California .............................................................................. 13 California-Off the coast ................................................................. 14 Hawaii ................................................................................ 14 Illinois .................._ ............................................................... 14 Missouri ............................................................................... 20 Montana ............................................................................... 21 Nevada ................................................................................ 21 New York .............................................................................. 21 Pennsylvania .......................· .................................................... 21 Utah .................................................................................. 21 Virginia ............................................................................... 22 Washington ............................................................................ 22 IV Earthquakes in the United States, April-June 1974 By R. B. Simon, C. W. Stover, and W. J. Person INTRODUCTION list of collaborators.) Anyone wishing to submit felt or damage information on earthqur.kes for The earthquake information in this publication inclusion in future reports should send it to the supplements that contained in the NElS National Earthquake Information Servk~, Stop (National Earthquake Information Service) 967, Box 25046, Denver Federal Center, Denver, publications, PDE ("Preliminary Determination Colo. 80225. Copies of the "Earthquake Report" of Epicenters") and "Preliminary Determin­ questionnaire can be obtained at this address. ation of Epicenters, Monthly Listing," to the The isoseismal maps were compiled from the extent of providing detailed felt and intensity data reported on the "Earthquake Report" forms data, as well as isoseismal maps for U.S. (fig. 1) supplemented by additional data from earthquakes. The purpose is to provide a other sources, such as newspaper art~~les or complete listing of macroseismic effects of information supplied by residents of tll e area. earthquakes, which can be used in risk studies, The primary method used by the NElS to collect nuclear powerplant sitings, seismicity studies, macroseismic information was a questionnaire and answering inquiries by the public. canvass using the "Earthquake Report" forms, This publication contains two major sections. which were mailed to postmasters in the area The first (table 1) is a tabular listing of affected by the earthquake. The postmasters earthquakes in chronological order by State, completed the forms and returned therr to the consisting of the following basic information: NElS where they were evaluated, an intensity Date, origin time, hypocenter, magnitude, value was assigned, and an isoseismal n~ap was maximum intensity, and the computational compiled. The isoseismals are based on a source of the hypocenter. The second section subjective grouping of intensity values, which consists of seven maps and table 2, which lists may be a single value or a range of values. Any detailed intensity information. The list of isoseismal may include a lower or higher earthquakes in table 1 was compiled from those intensity if it falls among a set of the values being located in the United States or off the coasts that contoured and cannot be differentiated by were published in the PDE; from hypocenters in another isoseismal. The lowest contour line may California above magnitude 3.5, supplied by not enclose all the points shown on tt~ map, California Institute of Technology, Pasadena, because the contouring encompasses o"lly the and the University of California at Berkeley; and contiguous intensity values. from any others that were felt or that caused damage, regardless of magnitude or availability These data will be made available for ir·~lusion of a hypocenter. Known or suspected explosions in the "Earthquake Description" sec~ion of are also listed. "United States Earthquakes," an annual The intensities and macroseismic data were publication, to which later data frorr other compiled from information obtained through sources may be added for the purp()ses of questionnaires sent to post offices in the updating and completeness. "United States epicentral area, from newspaper articles, and Earthquakes" is published jointly by tl'~ U.S. with the cooperation of other government Geological Survey, Department of the Interior, agencies, State institutions, local organizations, and the Environmental Data Service, NOAA, and individuals. (See "Acknowledgments" for a Department of Commerce. Bl U.S. DEPARTMENT OF THE INTERIOR Form Approved GEOLOGICAL SURVEY OMB No. 41-R0013 EARTHQUAKE REPORT 1. An earthquake was felt D not feH 0 Time ------A.M. Dateofshock ------------------- -------P.M If felt, please supply information below (Underline appropriate words or fill spaces.) If not feH, please s1gn and return card, wh1ch requires no postage. a. City, County, State .... Township, Range, Section, Quarter Section, or Geographic Coordinates -=c b. Ground: = z:O Rocky, gravelly, loose, compact, marshy, f1lled in, or o:z: -t-t-c.:: Level, sloping, steep, or u...,cc 9c:t c. H inside, type of construction: d. Qullity of construction: c.:!: ::tC.:: o= Wood, brick, stone, or New, old, well built, poorly buiH, or >o-Q e. No. of floors f. Observer's g. Activity when earthquake occurred: h. H outside, you, c-J in buildi111: floor: Walking, sitting, lymg down, others w•e: sleeping Quiet, active a. Fell by: !~ No one, very few, several, many, all (in your home) (in community) b. Awakened: u-'~== .... = No one, few, many, all (in your home) (in community) '-~ '-0 c. Frilhtened: .... ~ c.,; No one, few, many, all (in your home) (in community); general panic Qcn .... Q a. Rllllling of wiltdows, doors, dishes, etc . t-z :5::..... o b. Creaking of building (Describe) c.:: en .. c. Earth noises: Faint, moderate, loud a. Outside: .... (1) Trees and bushes shaken, vehicles rocked, etc . ~ (2) Ground cracked; landslides; water disturbed, etc. ::E c