United States Earthquakes, 1985 U.S. GEOLOGICAL SURVEY BULLETIN 1954 AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the cur­ rent-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Sur­ vey publications released prior to the current year are listed in the most recent annual "Price and Availability List." Publications that are listed in various U.S. Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and Availability List" are no longer available. Prices of reports released to the open files are ~iven in the listing "U.S. Geological Survey Open-File Reports," updated month­ ly, which is for sale in microfiche from the U.S. Geological Survey, Books and Open-File Reports Section, Federal Center, Box 25425, Denver, CO 80225. 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E-146, 701 C St. Maps For maps, address mail orders to U.S. Geological Survey, Map Distribution Maps Federal Center, Box 25286 Maps may be purchased over the counter at the U.S. Geologi­ Denver, CO 80225 cal Survey offices where books are sold (all addresses in above list) and at the following Geological Survey offices: Residents of Alaska may order maps from • ROLLA, Missourl--1400 Independence Rd. Alaska Distribution Section, U.S. Geological Survey, • DENVER, Colorado--Map Distribution, Bldg. 810, Federal New Federal Building - Box 12 Center 101 Twelfth Ave., Fairbanks, AK 99701 • FAIRBANKS, Alaska--New Federal Bldg., 101 Twelfth Ave. United States Earthquakes, 1985 By CARL W. STOVER and LINDIE R. BREWER This publication summarizes data for earthquakes that occurred in the 50 States and Puerto Rico during 1985. Descriptions of individual earthquakes include hypocenters, magnitudes, intensities, and damages. The report also contains results from regional networks and data recorded by strong-motion seismographs U.S. GEOLOGICAL SURVEY BULLETIN 1954 U.S. DEPARTMENT OF THE INTERIOR MANUEL LUJAN, JR., Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. UNITED STATES GOVERNMENT PRINTING OFFICE: 1991 For sale by the Superintendent of Documents U.S. Government Printing Office Public Documents Warehouse 8610 Cherry Lane Laurel, MD 20707 Library of Congress Cataloging-in-Publication Data 75-640209 (ISSN 0091-1429) Contributors Contributors to this publication are listed below according to the infonnation furnished or service perfonned: Hypocenters and magnitudes: John H. Minsch, U.S. Geological Survey, Denver, Colo. Robert Y. Koyanagi, Hawaiian Volcano Observatory, U.S. Geological Survey Intensities: Carl W. Stover, U.S. Geological Survey, Denver, Colo. Robert Y. Koyanagi, Hawaiian Volcano Observatory, U.S. Geological Survey Network operations (by institution) University of California, Berkeley, Calif. Hawaiian Volcano Observatory, U.S. Geological Survey, Hawaii. Lamont-Doherty Geological Observatory, Columbia University, Palisades, N. Y. Los Alamos National Laboratory, Los Alamos, N. Mex. New Mexico Institute of Mining and Technology, Socorro, N.Mex. Oklahoma Geological Survey, Leonard, Okla University of Nevada-Reno, Nev. University of Utah, Salt Lake City, Utah. University of Washington, Seattle, Wash. Virginia Polytechnic Institute and State University, Blacksburg, Va. Weston Observatory, Boston College, Weston, Mass. Strong-motion seismograph data: Ronald L. Porcella and Josephine C. Switzer U.S. Geological Survey, Menlo Park, Calif. Editorial assistance and manuscript preparations: Francis W. Baldwin, U.S. Geological Survey, Denver, Colo. CONTENTS Introduction 1 Discussion of tables 1 Epicenter and isoseismal maps 1 Magnitude and intensity 3 Modified Mercalli Intensity scale of 1931 5 CoUaborators 8 Earthquake descriptions 9 Alaska 9 Arizona 19 Arkansas 19 California 20 Colorado 38 Comecticut 38 Delaware 38 Hawaii 38 Idaho 42 Illinois 43 Indiana 44 Kentucky 44 Maine44 Massachusetts 44 Missouri 44 Montana 44 Nevada 52 New Hampshire 55 New Jersey 55 New Mexico 55 NewYork 55 North Carolina 60 North Dakota 61 Oklahoma 61 Oregon 62 Pemsylvania 62 Puerto Rico 62 South Carolina 63 Temessee 63 Texas 64 Utah 64 Virginia 65 Washington 65 Wyoming 66 Contents V Network operations 131 Northern and central California earthquakes, 1985, by Robert A. Uhrbammer 131 Hawaii earthquakes, 1985, by Robert Y. Koyanagi 131 Mississippi Valley earthquakes, 1985, by W. Stauder, R. Hemnann, John Chulick, S. Neiers, S. Horton, C. Carr, and C. Finn 132 Western Nevada and eastern California earthquakes, 1985, by Ute R. Vetter 137 New England seismicity, 1985, by James P. McCaffrey, S.J. 139 Seismicity of New Mexico, 1985, by Allan Sanford, Lawrence Jaksha, and Dan Cash 140 Socorro, New Mexico area earthquakes, 1985, by Allan Sanford, Lawrence Jaksha, Shirley Wade, and Kevin King 141 Oklahoma earthquakes, 1985, by James. B. Lawson, Jr., and Kenneth V. Luza 143 Southeastern United States earthquakes, 1985, by M.S. Sibol, M.C. Chapman, and G.A. Bollinger 14(; Utah earthquakes, 1985, by Ethan D. Brown 14(; Washington earthquakes, 1985, by R.S. Ludwin, S.D. Malone, R.S. Crosson, and A.I. Qamar 149 Miscellaneous activities 154 Principal earthquakes of the World for 1985 154 Strong-motion seismograph data, by Ronald L. Porcella and Josephine C. Switzer 157 Introduction 157 Accelerograph data 157 References cited 169 FIGURES [All figures are maps] 1. Earthquake epicenters in the contenninous United States for 1985 2 l. Earthquake epicenters in Alaska for 1985 l 3. Earthquake epicenters in Hawaii for 1985 3 4. Epicenters in the contenninous United States for earthquakes with magnitudes~ 5.0 in 1985 4 5. Epicenters in Alaska for earthquakes with magnitudes ~ 5.0 in 1985 4 6. Earthquakes in the contenninous United States that were felt or caused damage in 1985 6 7. Earthquakes in Alaska that were felt or caused damage in 1985 6 8. Earthquakes in Hawaii that were felt or caused damage in 1985 7 9. Isoseismal map for the northeastern Arkansas earthquake of06 September 1985,22 17 02.8 UTC l1 10. lsoseismal map for the central California earthquake of 08 February 1985, 06 58 16.9 UTC l3 11. Isoseismal map for the Avenal, California, earthquake of04 August 1985, 12 0157.0 UTC 32 12. lsoseismal map for the southern California earthquake of02 October 1985,23 44 12.4 UTC 36 13. Isoseismal map for the northwestern Montana earthquake of 01 April, 1985, 09 13 14.2 UTC 45 14. Isoseismal map for the southeastern New York earthquake of 19 October, 1985, 10 07 40.3 UTC 56 15. Isoseismal map for the southeastern New York earthquake of 21 October, 10 37 15.2 UTC 61 16. University of California seismographic station network during 1985 131 17. Northern and central California seismicity during 1985 13l 18. Shallow earthquakes located beneath the island of Hawaii during 1985 133 19. Crustal earthquakes located beneath the island of Hawaii during 1985 133 lO. Deep earthquakes located beneath the island of Hawaii during 1985 134 l1. Earthquakes located in the Hawaiian islands during 1985 134 ll. Location of the seismograph stations of the Central Mississippi Valley telemetered microearthquake network 135 23. Earthquakes located by the Central Mississippi Valley network during 1985 within a 4° by 5° region centered at 36.5°N. by 89.5°W. 135 VI Contents 24. Earthquakes located by the Central Mississippi Valley Earthquake network within the 1.5° by 1.5° area of the immediate New Madrid region 135 25. The western Nevada and eastern California seismic network stations during 1985 136 26. Seismicity of the western Nevada-eastern California area during 1985 137 27. Mammoth Lakes-Bishop, California area, earthquakes during 1985 138 28. Northeastern United States earthquakes during 1985 139 29. Earthquakes in New Mexico during 1985 141 30. Seismicity of the Socorro, New Mexico, area during 1985 142 31. Active seismograph stations in Oklahoma for 1985 144 32. Distribution of Oklahoma earthquakes for 1985 144 33.