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The Alaska Earthquake Regional Effects The Alaska Earthquake March 27,1964: Regional Effects This volume was published as separate chapters A-J GEOLOGICAL SURVEY PROFESSIONAL PAPER 543 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director CONTENTS [Letters designate the separately published chapters] ('1) Slide-induced waves, seiching, and ground fracturing caused by the earthquake of March 27, 1964, at Kenai Lake, Alaska, by David S. McCulloch. (B) Geomorphic effects of the earthquake of March 27, 1964. in the Martin-Bering Rivers area, Alaska, by Samuel J. Tuthill and Wilson M. Laird. (C) Gravity survey and regional geology of the Prince William Sound, epicentral region. Alaska, by J. E. Case, L). F. Barnes, George Plafker, and S. L. Robbins. (D) Geologic effects of the March 1964 earthquake and associated seismic sea waves on Kadiali and nearby islands, Alaska, by George Plafker and Reuben Kachadooria~~. (E) Effects of the earthquake of Marc11 27. 1964, in the Coljl~erRiver Basin area, Alaska, by Oscar J. Ferrians, Jr. (F) Ground breakage and associated effects ill the Cook Inlet area. Alaska, resulting from the JIarch 27, 1964, earthquake, by Helen L. Foster and Thor x. V. Karlstrorn. (G) Surface faults on Montague Island associated with the 1964 Alahka earthquake, by George Plaflter. (13) Erosion and deposition on a beach raised by the 19ki4 earthyuake. Jfontagne Island, Alaska, by 11. J. Kirkby and Anne V. Kirkby. (I) Tectonics d the March 27,1964, Alaska earthquake. by Grorge I'lafker. (J) Effects of the Alaska earbhquake of March 27. 1964, on shore processes and beach ~norphology, by Kirk W. Stanley. U.S. GOVERNMENT PRINTING OFFICE: 1968 0 298-580 STOLEN FROM RiCHARD D. REGW THE ALASKA EARTHQUAKE, MARCH 27, 1964: REGIONAL EFFECTS Effects of the Alaska Earthquake of March 27, 1964 On Shore Processes and Beach Morphology Bg KIRK W. STANLEY The efects of tectonic uplift and subsidence along 10,000 miles of shoreline, and the practical meaning of those eflects GEOLOGICAL SURVEY PROFESSIONAL PAPER 543-5 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1968 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 45 cents (paper cover) THE ALASKA EARTHQUAKE SERIES The U.S. Geological Survey is publishing the re- sults of its investigation~of the Alaska earthquake I of March 27, 1964, in a series of sin Professional 1 Papers. Professional Paper 543 describes the re- 1 gional effects of the earthquake. Other Professional I Papers in ithe series describe field investigations and reconstruction and the effects of the earthquake on communities, on the hydrologic regimen, and on transportation, utilities, and communications. I i~ CONTENTS Page Coastal features and earthquake Introduction -__-__-------------- 1 effects -Continued Shorelines of the earthquake-af- Coastal erosion and movement. fected region --------______---2 of material-Continued Coastal features and earthquake Longshore material move- effects -----_-_____-----------3 ment _ _ _ _ _ - - - _ _ - - _ _ _ _ Beaches--______--__________ 3 Upslope material move- Changes in profile and ment_---_-_-_-_-_-__ gradient ---__---______3 Biologic effects of shoreline Minor beach features- - - .. - 5 changes-.-__.__.___---------. Low-water features- - - - - - 6 Fish__-_________---_____-__ Modern beach ridges--- - - 7 Shellfish - - - - _ _ _ _ _ - - - - - - - - - - - Wildfowl _ _ - _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ Ancient beach ridges--- - - 10 Effects on property and manmade Stream-mouth changes-_----- 10 structures..- - _ _ _ - _ _ _ _ _ _ _ - _ _ _ _ _ _ Submergent areas --__-__10 Submergent areas- - --- _____- Uplifted areas--_- - _ - _ - _ - 11 Emergent areas --_--_____-_- Coastal erosion and movement Legal problems --_---________ of material ---_______-____12 Need for further studies --_-_---_- Erosion ----_--_________12 References cited -----__--___-____ ILLUSTRATIONS FIGURES Page Page 1. Index map of south-central Alaska showing coast- 9. Photograph of gullying and sloughing caused by lines affected by the earthquake -----_-------- VI headward stream erosion, Copper River Delta- 2. Diagram illustrating beach feature- - - _ - - ____ __ - 53 10. Photograph of eastern shore of Cook Inlet showing 3. Photograph of sharp break-in-slope on shingle undercutting and sloughing of bluffs caused by beach--__------.-------------------------- 4 subsidence----__---------..-.-----------.-- 4. Sketch of changes of beach configuration in sub- 11. Photograph of bluff erosion at Kenai ---_-_____-- mergentareas--------______-----------.-.-- 5 12-14. Photographs of timber seawall on Homer Spit: 5. Photograph of deposition of material on backslope 12. As constructed --._------------.-------- of frontal ridge-------_-_____----__-___--_-8 13. Damaged, 6 months after construction._ - - 6. Aerial photograph of barrier beach at Breving 14. Almost completely destroyed by waves, 16 Lagoon, Seward Peninsula --__--____-- -- -- -- - 9 months after construction-- .---------- 7. Photograph showing undercutting and sloughing 15. Photograph of cobble-filled wire-mesh fence, of bluffs, Cook Inlet- ___________--______-___9 Larsen Bay, Kodiak Island -.--------_------- 8. Oblique photograph of new land created by tec- 16. Profiles of updrift and downdrift fill of grain at tonic uplift, Copper River Delta ------_______ 11 Homer Spit---.---------------------------- 100 15C MILES - - --- 1.- South-central Alaska showing cmstlines affected by the earthquake. Land to left of zero land-level change was generally lowered ; land to right was raised. THE ALASKA EARTHQUAKE, MARCH 27,1964: REGIONAL EFFECTS EFFECTS OF THE ALASKA EARTHQUAKE OF MARCH 27, 1964, ON SHORE PROCESSES AND BEACH MORPHOLOGY By Kirk W. Stanley ABSTRACT Some 10,000 miles of shoreline in were altered or destroyed on submerg- Streams were lengthened in the emer- south-central Alaska was affected by the ence but began to reappear and to gent areas, and down cutting and bank subsidence or uplift associated with the stabilize in their normal shapes within erosion hare increased. great Alaska earthquake of March 27, a few months after the earthquake. Except at Honler and a few small vil- 1964. The changes in shoreline processes Frontal beach ridges migrated shore- lages, where groins, bulkheads, and and beach morphology that were sud- ward and grew higher and wider than cobble-filled baskets were installed, denly initiated by the earthquake were they were before. Along narrow beaches there has been little attempt to protect similar to those ordinarily caused by backed by bluffs, the relatively higher the postearthquake shorelines. The few gradual changes in sea level operating sea level led to vigorous erosion of the structures that were built have been over hundreds of years, while other bluff toes. Stream mouths were drowned only partially successful because there more readily visible changes were sim- and some were altered by seismic sea was too little time to study the habits ilar to some of the effects of great but w'aves, but they adjusted within a few of the new shore features and to design short-lived storms. Phenomena became months to the new conditions. appropriate protection measures. Emer- available for observation within a few In the uplifted areas, generally around gence of large areas that were once hours which would otherwise not have Prince William Sound, virtually all been available for many years. beaches were stranded out of reach of below water and permanent submer- In the subsided areas-including the the sea. New beaches are gradually de- gence of onceuseful land areas have led shorelines of the Kenai Peninsula, veloping to fit new sea levels, but the to many problems of land use and Kodiak Islanjd, and Cook Inlet-beaches processes are slow, in part because the ownership in addition to the destruction tended to flatten in gradient and to re- material on the lower parts of the old or relocation of wildfowl, shellfish, and cede shoreward. Minor beach features beaches is predominantly fine grained. salmon habitats. INTRODUCTION One of the strongeat earthquakerj lowered as much as 71/2 feat and by the earthquake are included, ever reported occurred in alaska 25,000 'quare miles was raised as the shoreline within the area ex- on March 27, 1964, at 5:36 p.m. much as 33 feet (Plafker, 1965, ceeds 10,000 nautical miles. Alaska standard time. The epi- 1967). The coastlines affected by Certain changes in beach forms center was at Unakwik Inlet in the earthquake are shown by occurred as a result of relative Prince William Sound (fig. 1). figure 1. changes in sea level caused by up- The magnitude of the main shock Definite limits of the coastal area lift or subsidence of the land dur- was 8.4-8.6 on the Richter scale of Alaska affected by the earth- ing the earthquake. These changes (Wood, 1966). The area of land quake have not been determined. were abrupt and thus cannot be and sea bottom affected by the Most authorities, ho~vever,agree unconditionally compared to i~ earthquake is at least 70,000 square that it is bounded by Yakataga gradual change in sea level, but miles and may exceed 110,000. (just southeast of the area shown they did provide much informa- Forty thousand square miles was in figure 1) on the east and the tion regarding normal shore proc- Kodiak group of islands 011 the esses. Because sea-level changes southwest (Plafker, 1965). If all were not only abrupt but also ' Geologist, Anchorage, Alaska ; formerly Tidelands Supervisor, Alaska Department of the shoreline irregularities of the permanent, months were afforded Natural Rcsonrces. Division of Lands. mainland and the islands affected for observations, which other- J1 52 ALASKA EUTRQUAKE, MARCH 27, 1964 wise-as during storms-would problems. These limited observa- available. Descriptions of coastal have been limited to hours or at tions do not reflect all conditions erosion primarily involve exam- the most several days.
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