Lessons and GEOLOGICAL SURVEY PROFESSIONAL PAPER 546 This page intentionally left blank The Alaska Earthquake March 27, 1964: Lessons and Conclusions By EDWIN B. ECKEL A summary of what was learned from a great earthquake about the bearing of geologic and hydrologic conditions on its effects, and about the scientific investigations needed to prepare for future earthquakes GEOLOGICAL SURVEY PROFESSIONAL PAPER 546 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY W. A. Radlinski, Acting Director Library of Congress catalog-card No. 70-604792 First printing 1970 Second printing 1971 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1970 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 75 cents (paper cover) FOREWORD Few of the effects of the Alaska earthquake of March 27, 1964, on earth processes and on the works of man were new to science, but never had so many effects been accessible for study over so great an area. This earthquake has received more intensive study from all scientific disciplines and specialties than any single previous natural disaster. In a series of six Professional Papers, the U.S. Geological Survey has published the results of a comprehensive geologic study that began, as a reconnaissance survey, within 24 hours after the event and extended, as detailed investigations, through several field seasons. Professional Paper 541 de­ scribed early field investigations and reconstruction efforts; 542, in seven parts, the effects of the earthquake on Alaskan communities; 543, in 10 parts, the regional geologic effects; 544, in five parts, the worldwide effects on the earth's hydro­ logic regimen; 545, in four parts, the effects on Alaska's transportation, communications, and utilities. This volume, Professional Paper 546, "Lessons and Conclusions," is the last of the series; it contains a selected bibliography and an index for the 28 reports. The findings of the Geological Survey study apply not only to documentation of the Alaska earthquake itself, but, it is hoped, toward 'better understanding of earthquakes jn general; their nature, origin, and effects, and of how man may plan or build to avoid or minimize their consequences. w. T. PECORA, Direat01'. This page intentionally left blank CONTEN·Ts·. Pare Effects, etc.-continued Beneficial effects-continued l'a&e Abstract---------------------- 1 Oceanographic effects-con. Page Scientific benefits ___________ _ 32 Introduction _______ -_--- ____ -- 2 Seismio·sea waves ________ _ 25 New information---------­ 32 Geological Survey reports on Miscellaneous effects ________ _ 26 New and improved investi- theearthquake____________ 3 Audible and subaudible gative techniques ___ - ___ _ 34 Acknowledgments---_________ 8 earthquake sounds _____ _ 26 Conclusions __________________ _ 37 Tectonics_! __________ -------_-- 8 Magnetic effects-------- __ _ 26 Scientific preparation for The earthquake_____________ 8 Visible surface waves ______ _ 26 future earthquakes _____ _ 37 Deformation and vibration of Permafrost __ ------------_ 27 Fundamental research_---­ 37 the land surface___________ 9 Cable breaks _______ --____ _ 27 Earthquake forecasting and Vertical deformation_________ 11 Tunnels, mines, and deep evaluationhazards _______________ of earthquake _ Horisontal deformation_ _ _ _ __ 11 wells----------·-------- 27 37 Surface faults_______________ 12 Archeologic remains ______ _ 28 Geologic mapping of Mechanism of the earthquake_ 13 communities ___ - _______ _ 38 Earthquakedamage _________________effects, geology and _ Effects on the physical environ- Instrumenta~ion and meas- 28 urements ______________ _ ment_____________________ 14 Geologic control of vibration 40 Geologic effects_____________ 14 damage _________________ _ 29 Investigationsquakes ________________ of actual earth- _ Downslope mass movements_ 14 Surface faults ______________ _ 30 41 Need for advance planning_ 41 Ground fissures----------- 19 Landslides ________ --_______ _ 30 Consolidation subsidence___ 21 Geologic, geophysical, and Shore processes-__________ 21 Vertical tectonic displacements and seismic sea waves _____ _ hydrologic investigations_ 41 Hydrologic effects____________ 21 30 Availability of maps and Ground and surface water Glaciers__________________ 21 hydrology _______________ _ other basic data _______ _ 41 Ice breakage______________ 22 31 Questionnaires ___________ _ 41 Ground water_____________ 22 Beneficialquake ___________________ effects of the earth- _ Scientific and Engineering Surface water_____________ 23 31 Task F.orce--------------­ 43 Oceanographic effects________ 23 Socioeconomic benefits ______ _ 31 Selected bibliography_--------- 43 Local waves______________ 24 Direct geologic benefits _____ _ 32 IndeX------------------------ 49 ILLUSTRATIONS FIGURES Page 1. Map showing extent and nature of the effects of seismic vibrations related to the earthquake------------------------------------------------------------ 4-5 2. Map of south-central Alaska, showing areas of tectonic land-level changes________ 10 "One of the greatest earthquakes of all time· struck in south-central Alaska in the late afternoon of March 27, 1964." THE ALASKA EARTHQUAKE, MAR,CH 27, 1964: LESSONS AND CONCLUSIONS By Edwin B. Eckel ABSTRACT One of the greatest earthquakes of water, caused much damage in towns The geologic and hydrologic lessons all time struck south-central Alaska on and along transportation routes. Vibru- learned from studies of the Alaska March 27, 1964. Strong motion lasted tion also consolidated loose granular earthquake also lead direetly to longer than for most recorded earth- materials. In some coastal areas, local better definition of the research quakes, and more land surface was dis- subsidence was superimposed on re- needed to further our understanding located, vertically and horizontally, gional tectonic subsidence to heighten of earthquakes and of how to avoid than by any known previous temblor. the flooding damage. Ground and sur- or lessen the effects of future ones. Never before were so many effects on face waters were measurably affected Research is needed on the origins earth processes and on the works of by the earthquake, not only in Alaska and mechanisms of earthquakes, on man available for study by scientists but throughout the world. cnistal structure, and on the genera- and engineers over so great an area. Expectably, local geologic conditions tion of tsunamis and local waves. The seismic'vibrations, which directly largely controlled the extent of struc- Better earthquake-hazard maps, based or indirectly caused most of the damage, tural damage, whether caused directly on improved knowledge of negioml ge- were but surface manifestations of a by seismic vibrations or by secondary ology, fault behavior, and earthquake great geologic event-the dislocation of effects such as those just described. mechanisms, are needed for 'the entire a huge segment of the crust along a Intensity was greatest in areas under- country. Their preparation will require deeply buried fault whose nature and lain by thick saturated unconsolidated the close collaboration of engineers, even exact location are still subjects for deposits, least on indurated bedrock or seismologists, and geologists. Geologic speculation. Not only was the land sur- permanently frozen ground, and inter- maps of all inhabited places in earth- face tilted by the great tectonic event mediate on coarse well-drained gravel, quakeprone parts of the country are beneath it, with resultant seismic sea on morainal deposits, or on moderately also needed by city planners and others, waves that traversed the entire Pacific, indurated sedimentary rocks. because the direct relationship between but an enormous mass of land and sea Local and even regional geology also local geology and potential earthquake floor moved ,several tens of feet hori- controlled the distribution and extent damage ts now well understood. zontally toward the Gulf of Alaska. of the earthquake's effects on hydro- Improved and enlarged nets @f Downslope mass movements of rock, logic systems. In the conterminous earthquake-sensing instruments, sited earth, and snow were initiated. Sub- United States, for example, seiches in in relation to known geology, are aqueous slides along lake shores and wells and bodies of surface water were needed, as are many more geodetic seacoasts, near-horizontal movements of controlled by geologic structures of mobilized soil ("landspreading") , and regional dimension. and hydrographic measurements. giant translatory slides in sensitive Devastating as the earthquake was, Every large earthquake, wherever clay did the most damage and provided it had many long-term beneficial ef- located, should be regarded as a full- the most new knowledge as to the origin, fects. Many of these were socioeco- scale laboratory experiment whose mechanics, and possible means of con- nomic or engineering in nature; others study can give scientific and engineer- trol or avoidance of such movements. were of scientific value. Much new ing information unobtainable from any The slopes of most of the deltas that and corroborative basic geologic and other source. Plans must be made slid in 1964, and that produced de- hydrologic information was accumu- before the event to insure staffing, structive local waves, are still as steep lated in the course of the earthquake funding, and coordination of effort for or steeper than they were before the studies, and many new