1964 Alaska earthquake - wikipedia 1964 Alaska earthquake 1964 Alaska earthquake Fourth Avenue in Anchorage, Alaska, looking east from near Barrow Street. The southern edge of one of several landslides in Anchorage, this one covered an area of over a dozen blocks, including 5 blocks along the north side of Fourth Avenue. Most of the area was razed and made an urban renewal district. Date March 27, 1964 ( 1964 - 03 - 27 ) Origin time 17 : 36 : 16 AST Duration 4 - 5 minutes. Magnitude 9.2 M Depth 25 kilometres ( 16 mi ) Epicenter 60 ° 54 ′ 29 '' N 147 ° 20 ′ 20 '' W ﻿ / ﻿ 60.908 ° N 147.339 ° W ﻿ / 60.908 ; - 147.339 Type Megathrust Areas affected United States, Canada Total damage $311 million Max. intensity XI ( Extreme ) Peak acceleration 0.18 g Tsunami Major. Run - up of 67 m ( 220 ft ) at Shoup Bay, Alaska. Casualties 139 killed The 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5 : 36 PM AST on Good Friday, March 27. Across south - central Alaska, ground fissures, collapsing structures, and tsunamis resulting from the earthquake caused about 139 deaths. Lasting four minutes and thirty - eight seconds, the magnitude 9.2 megathrust earthquake was the most powerful recorded in North American history, and the second most powerful recorded in world history. Soil liquefaction, fissures, landslides, and other ground failures caused major structural damage in several communities and much damage to property. Anchorage sustained great destruction or damage to many inadequately earthquake engineered houses, buildings, and infrastructure ( paved streets, sidewalks, water and sewer mains, electrical systems, and other man - made equipment ), particularly in the several landslide zones along Knik Arm. Two hundred miles southwest, some areas near Kodiak were permanently raised by 30 feet ( 9.1 m ). Southeast of Anchorage, areas around the head of Turnagain Arm near Girdwood and Portage dropped as much as 8 feet ( 2.4 m ), requiring reconstruction and fill to raise the Seward Highway above the new high tide mark. In Prince William Sound, Port Valdez suffered a massive underwater landslide, resulting in the deaths of 30 people between the collapse of the Valdez city harbor and docks, and inside the ship that was docked there at the time. Nearby, a 27 - foot ( 8.2 m ) tsunami destroyed the village of Chenega, killing 23 of the 68 people who lived there ; survivors out - ran the wave, climbing to high ground. Post-quake tsunamis severely affected Whittier, Seward, Kodiak, and other Alaskan communities, as well as people and property in British Columbia, Washington, Oregon, and California. Tsunamis also caused damage in Hawaii and Japan. Evidence of motion directly related to the earthquake was also reported from Florida and Texas. Contents 1 Geology 2 Tsunamis 3 Death toll, damage, and casualties 3.1 Anchorage area 3.2 Elsewhere in Alaska 3.3 Canada 3.4 Elsewhere 4 Aftershocks 5 Recovery efforts 6 References 6.1 Specific 6.2 General 7 External links Geology At 5 : 36 p.m. Alaska Standard Time ( 3 : 36 a.m. March 28, 1964 UTC ), a fault between the Pacific and North American plates ruptured near College Fjord in Prince William Sound. The epicenter of the earthquake was 12.4 mi ( 20 km ) north of Prince William Sound, 78 miles ( 125 km ) east of Anchorage and 40 miles ( 64 km ) west of Valdez. The focus occurred at a depth of approximately 15.5 mi ( 25 km ). Ocean floor shifts created large tsunamis ( up to 220 feet ( 67 m ) in height ), which resulted in many of the deaths and much of the property damage. Large rockslides were also caused, resulting in great property damage. Vertical displacement of up to 38 feet ( 11.5 m ) occurred, affecting an area of 100,000 miles2 ( 250,000 km2 ) within Alaska. Studies of ground motion have led to a peak ground acceleration estimate of 0.14 -- 0.18 g. The Alaska earthquake was a subduction zone earthquake ( megathrust earthquake ), caused by an oceanic plate sinking under a continental plate. The fault responsible was the Aleutian Megathrust, a reverse fault caused by a compressional force. This caused much of the uneven ground which is the result of ground shifted to the opposite elevation. Tsunamis Calculated travel time map for the tectonic tsunami produced by the 1964 Prince William Sound earthquake in Alaska. Tsunami Travel Times computed using TTT v3. 1 ( P. Wessel ). Map does not show the height or strength of the waves, only the calculated travel times. Red : 1 - to 4 - hour arrival times Yellow : 5 - to 6 - hour arrival times Green : 7 - to 14 - hour arrival times Blue : 15 - to 21 - hour arrival times. Two types of tsunamis were produced by this subduction zone earthquake. There was a tectonic tsunami produced in addition to about 20 smaller and local tsunamis. These smaller tsunamis were produced by submarine and subaerial landslides and were responsible for the majority of the tsunami damage. Tsunami waves were noted in over 20 countries, including : Peru, New Zealand, Papua New Guinea, Japan, Mexico and Antarctica. The largest tsunami wave was recorded in Shoup Bay, Alaska, with a height of about 220 ft ( 67 m ). Tremors were detected in water wells in Australia. Death toll, damage, and casualties The largest landslide in Anchorage occurred along Knik Arm between Point Woronzof and Fish Creek, causing substantial damage to numerous homes in the Turnagain - By - The - Sea subdivision. The ruin of Portage A plank driven through a tire by the tsunami in Whittier The 5 - story JCPenney department store in Anchorage in 1964, following the earthquake. As a result of the earthquake, 139 people are believed to have died : Fifteen died as a result of the earthquake itself, 106 died from the subsequent tsunami in Alaska, 5 died from the tsunami in Oregon, and 13 died from the tsunami in California. The quake was a reported XI on the modified Mercalli Intensity scale `` indicating major structural damage, and ground fissures and failures ''. Property damage was estimated at about $311 million ( $2.32 billion in current U.S. dollars ). It is likely that the toll would have been much higher had the quake not occurred after 5 pm on Good Friday. Play media USGS video explaining the earthquake and footage Anchorage area Most damage occurred in Anchorage, 75 mi ( 120 km ) northwest of the epicenter. Anchorage was not hit by tsunamis, but downtown Anchorage was heavily damaged, and parts of the city built on sandy bluffs overlying `` Bootlegger Cove clay '' near Cook Inlet, most notably the Turnagain neighborhood, suffered landslide damage. The neighborhood lost 75 houses in the landslide, and the destroyed area has since been turned into Earthquake Park. The Government Hill school suffered from the Government Hill landslide, leaving it in two jagged, broken pieces. Land overlooking the Ship Creek valley near the Alaska Railroad yards also slid, destroying many acres of buildings and city blocks in downtown Anchorage. Most other areas of the city were only moderately damaged. The 60 - foot ( 18 m ) concrete control tower at Anchorage International Airport was not engineered to withstand earthquake activity and collapsed, killing William George Taylor, the Federal Aviation Agency air traffic controller on duty in the tower cab at the time the earthquake began. One house on W. 10th Avenue suffered peripheral damage, but only one block away the recently completed ( and still unoccupied ) Four Seasons Building on Ninth Avenue collapsed completely, with the concrete elevator shafts sticking up out of the rubble like a seesaw. The hamlets of Girdwood and Portage, located 30 and 40 mi ( 60 km ) southeast of central Anchorage on the Turnagain Arm, were destroyed by subsidence and subsequent tidal action. Girdwood was relocated inland and Portage was abandoned. About 20 miles ( 32 km ) of the Seward Highway sank below the high - water mark of Turnagain Arm ; the highway and its bridges were raised and rebuilt in 1964 -- 66. Elsewhere in Alaska Most coastal towns in the Prince William Sound, Kenai Peninsula, and Kodiak Island areas, especially the major ports of Seward, Whittier and Kodiak were heavily damaged by a combination of seismic activity, subsidence, post-quake tsunamis and / or earthquake - caused fires. Valdez was not totally destroyed, but after three years, the town relocated to higher ground 7 km ( 4 mi ) west of its original site. Some Alaska Native villages, including Chenega and Afognak, were destroyed or damaged. The earthquake caused the Cold - War era ballistic missile detection radar of Clear Air Force Station to go offline for six minutes, the only unscheduled interruption in its operational history. Near Cordova, the Million Dollar Bridge crossing the Copper River also collapsed. The community of Girdwood was also confined to the southern side of the Seward Highway when water rushed into Turnagain Arm and flooded or destroyed any buildings left standing to the north of the highway. Interestingly, only the ground immediately along the highway and that on the north side of the road dropped, prompting geologists to speculate that Girdwood may rest upon an ancient cliff face, now covered by countless thousands of years of sediment and glacial deposits. Canada A 4.5 ft ( 1.4 m ) wave reached Prince Rupert, British Columbia, just south of the Alaska Panhandle, about three hours after the earthquake. The tsunami then reached Tofino, on the exposed west coast of Vancouver Island, and traveled up a fjord to hit Port Alberni twice, washing away 55 homes and damaging 375 others. The towns of Hot Springs Cove, Zeballos, and Amai also saw damage. The damage in British Columbia was estimated at $10 million Canadian ( or $78.3 million in today 's Canadian dollars, or $58.3 million in today 's U.S. dollars ). Elsewhere A winter scene of a `` Ghost forest '' that was killed and preserved by salt water along with ruined buildings at the site of the former town of Portage, 2011 Twelve people were killed by the tsunami in or near Crescent City, California, while four children were killed on the Oregon coast at Beverly Beach State Park. Other coastal towns in the U.S. Pacific Northwest and Hawaii were damaged. Minor damage to boats occurred as far south as Los Angeles. Effects of the earthquake were even noted as far east as Texas. Tide gauges in Freeport recorded waves similar to seismic surface waves. In the Florida Everglades, an artesian aquifer located near Lake Chekika saw its water flow rate double from 3 million gallons per day to 6 million gallons per day, 60 to 90 minutes after the first shock of the earthquake. Aftershocks There were hundreds of aftershocks in the first weeks following the main shock. In the first day alone, eleven major aftershocks were recorded with a magnitude greater than 6.0. Nine more struck over the next three weeks. In all, thousands of aftershocks occurred in the months following the quake, and smaller aftershocks continued to strike the region for more than a year. Recovery efforts Alaska had never experienced a major disaster in a highly populated area before, and had very limited resources for dealing with the effects of such an event. The military, which has a large active presence in Alaska, stepped in to assist within moments of the end of the quake. The Army rapidly re-established communications with the lower 48 states, deployed troops to assist the citizens of Anchorage, and dispatched a convoy to Valdez. On the advice of military and civilian leaders, President Johnson declared all Alaska a major disaster area the day after the quake. The Navy and Coast Guard deployed ships to isolated coastal communities to assist with immediate needs. Bad weather and poor visibility hampered efforts at air rescue and observation efforts the day after the quake, but on Sunday the 29th the situation improved and rescue helicopters and observation aircraft were deployed. A military airlift immediately began shipping relief supplies to Alaska, eventually delivering 2,570,000 pounds ( 1,170,000 kg ) of food and other supplies. In the longer term, the US Army Corps of Engineers led the effort to rebuild roads, clear debris, and establish new townsites for communities that had been completely destroyed, at a cost of $110 million. The West Coast and Alaska Tsunami Warning Center was formed as a direct response to the disaster. Federal disaster relief funds paid for reconstruction as well as financially supporting the devastated infrastructure of Alaska 's government, spending hundreds of millions of dollars that helped keep Alaska financially solvent until the discovery of massive oil deposits at Prudhoe Bay. At the order of the Defense Department, the Alaska National Guard founded the Alaska Division of Emergency Services to respond to any future disasters. References Specific Jump up ^ USGS. `` M9. 2 - The Great Alaska Earthquake and Tsunami of March 27, 1964 ''. United States Geological Survey. Jump up ^ US Geological Survey report on the earthquake Archived 2009 - 08 - 25 at the Wayback Machine. ^ Jump up to : Tsunami Events Search - sorted by Date, Country, National Geophysical Data Center Jump up ^ USC, Tsunami Research Group. `` 1964 Alaskan Tsunami ''. University of Southern California. Retrieved 18 July 2015. Jump up ^ Historic Earthquakes : Prince William Sound, Alaska Archived 2014 - 10 - 11 at the Wayback Machine. Jump up ^ National Research Council ( U.S. ). Committee on the Alaska Earthquake, The great Alaska earthquake of 1964, Volume 1, Part 1, National Academies, 1968 p. 285 ^ Jump up to : `` Getting Ready to Rumble '', Richard Conniff, Wall Street Journal, August 26, 2017 Jump up ^ The Great Alaskan Earthquake & Tsunamis of 1964, by the National Oceanic and Atmospheric Administration. Accessed 2009 - 06 - 23. Archived 2009 - 06 - 25. Jump up ^ ushistory.com : Great Alaskan Quake of 1964 - Retrieved 2014 - 06 - 10 Jump up ^ Sozen, Mete A. and N. Norby Nielsen, 1973 : Analysis of the failure of the Anchorage International Airport control tower. The great Alaska earthquake of 1964, Volume 3, Part 2, National Research Council ( U.S. ). Committee on the Alaska Earthquake, National Academy of Sciences, ISBN 0 - 309 - 01606 - 1. Jump up ^ `` Tsunami runups in Canada in 1964 ''. National Oceanic and Atmospheric Administration. Jump up ^ Oregon 's pioneer spirit. Statesman Journal, December 26, 1999. ^ Jump up to : USGS Release : 40th Anniversary of `` Good Friday '' Earthquake Offers New Opportunities for Public and Building Safety Partnerships ( 3 / 26 / 2004 ) Jump up ^ `` Tsunami runups in Freeport ''. National Oceanic and Atmospheric Administration. Jump up ^ `` Everglades Chekika : Fountain ''. National Park Service. ^ Jump up to : Cloe, John Haile `` Helping Hand '' Military response to Good Friday earthquake Alaska Historical Society, 3 / 4 / 2014 ^ Jump up to : Galvin, John Great Alaskan Earthquake and Tsunami : Alaska, March 1964 Popular Mechanics, 6 / 29 / 2007 General National Research Council, Committee On The Alaska Earthquake ( 1971 -- 73 ). The Great Alaska Earthquake Of 1964. Washington : National Academy of Sciences. Geology, Seismology and Geodesy, Hydrology, Biology, Oceanography And Coastal Engineering, Engineering, Human Ecology, Summary and Recommendation External links Wikimedia Commons has media related to Good Friday Earthquake. The Face of Disaster : The Great Alaska Earthquake - US Office of Civil Defense 1964 Good Friday Great Alaskan Earthquake -- University of Arizona, Department of Geosciences 1964 Great Alaska Earthquake -- United States Geological Survey The Effects of the March 28, 1964 Alaska Tsunami in British Columbia, Canada -- George Pararas - Carayannis The Great Alaska Earthquake of 1964 -- Alaska earthquake Information Center The short film ALASKAN EARTHQUAKE ( 1966 ) is available for free download at the Internet Archive Anchorage, AK Good Friday Earthquake, Mar 1964 -- GenDisasters.com Tsunami Anniversary -- Oregon Field Guide Fifty Years Since the Great Alaska Earthquake : The Role of First Responders in Catastrophic Disaster Planning -- 113th United States Congress Tsunami Forecast Model Animation : Alaska 1964 -- Pacific Tsunami Warning Center ← Earthquakes in 1964 → Baihe ( 6.3, Jan 18 ) † Alaska ( 9.2, March 27 ) † ‡ Niigata ( 7.6, June 16 ) † Guerrero ( 7.2, July 6 ) † Manyas ( 6.8, Oct 6 ) † indicates earthquake resulting in at least 30 deaths ‡ indicates the deadliest earthquake of the year Earthquakes in Alaska 1906 Aleutian Islands ( 8.35 ) 1946 Aleutian Islands ( 8.6 ) 1957 Andreanof Islands ( 8.6 ) 1958 Lituya Bay ( 7.8 ) 1964 Alaska ( 9.2 ) 1965 Rat Islands ( 8.7 ) 1975 Near Islands ( 7.6 ) 2002 Denali ( 7.9 ) 2014 Aleutian Islands ( 7.9 ) 2014 Palma Bay ( 6.0 ) 2016 Old Iliamna ( 7.1 ) Earthquakes in the United States Historical 1638 New Hampshire 1663 Charlevoix 1700 Cascadia 1755 Cape Ann 1811 -- 12 New Madrid 1838 San Andreas 1857 Fort Tejon 1865 Memphis 1867 Manhattan, Kansas 1868 Hawaii 1868 Hayward 1872 Lone Pine 1872 North Cascades 1886 Charleston 1887 Sonora 1892 Laguna Salada 1892 Vacaville -- Winters 1898 Mare Island 20th - century 1906 San Francisco 1906 Aleutian Islands 1909 Wabash River 1915 Pleasant Valley 1916 Irondale 1918 San Jacinto 1925 Santa Barbara 1931 Valentine 1932 Eureka 1933 Long Beach 1935 Helena 1940 El Centro 1940 New Hampshire 1944 Cornwall -- Massena 1946 Aleutian Islands 1947 Wisconsin 1948 Desert Hot Springs 1949 Olympia 1952 Kern County 1957 Andreanof Islands 1957 San Francisco 1959 Hebgen Lake 1964 Alaska 1965 Rat Islands 1965 Puget Sound 1968 Illinois 1969 Santa Rosa 1971 San Fernando 1973 Point Mugu 1975 Near Islands 1975 Morris 1975 Hawaii 1979 Coyote Lake 1979 Imperial Valley 1980 Eureka 1983 Coalinga 1983 Borah Peak 1984 Morgan Hill 1986 North Palm Springs 1986 Chalfant Valley 1987 Whittier Narrows 1989 Loma Prieta 1990 Upland 1991 Sierra Madre 1992 Cape Mendocino 1992 Landers 1992 Big Bear 1993 Scotts Mills 1993 Klamath Falls 1994 Northridge 1995 Marathon 1996 Duvall 1998 Pymatuning 1999 Hector Mine 2000 Yountville 21st - century 2001 Nisqually 2002 Denali 2003 Alabama 2003 San Simeon 2006 Gulf of Mexico 2006 Kiholo Bay 2007 Alum Rock 2008 Illinois 2008 Chino Hills 2010 Eureka 2010 Baja California 2010 Indiana 2011 Colorado 2011 Virginia 2011 Oklahoma 2014 Aleutian Islands 2014 Southeast Alaska 2014 South Napa 2016 Oklahoma 2016 Hawthorne Swarms 2001 Enola 2008 Reno 2010 -- 11 Guy - Greenbrier 2012 Brawley 2009 -- 17 Oklahoma History of Alaska Timeline of Alaska Prehistory Russian America ( 1733 -- 1867 ) Department of Alaska ( 1867 -- 1884 ) District of Alaska ( 1884 -- 1912 ) Territory of Alaska ( 1912 -- 1959 ) Recent history ( 1959 -- present ) Topics and events Russian - American Company Alaska Purchase Gold Rush era Klondike Nome Fairbanks Alaska boundary dispute 1925 serum run to Nome World War II Aleutian Islands Campaign Project Hula Alaska Statehood Act 1964 earthquake Alaska Native Claims Settlement Act Alaska National Interest Lands Conservation Act Exxon Valdez oil spill History of Anchorage timeline History of Fairbanks Other topics Retrieved from `` https://en.wikipedia.org/w/index.php?title=1964_Alaska_earthquake&oldid=806874441 '' Categories : 1964 earthquakes 1964 in Alaska 1964 in Canada 1964 in Hawaii Earthquakes in British Columbia Landslides in the United States Megathrust earthquakes in Alaska Megathrust earthquakes in Canada 1964 tsunamis Tsunamis in the United States Tsunamis in New Zealand Landslides in 1964 1964 natural disasters in the United States March 1964 events 1964 in British Columbia Hidden categories : Webarchive template wayback links All articles with unsourced statements Articles with unsourced statements from January 2010 Articles containing video clips Talk Contents About Wikipedia Afrikaans Català Čeština Dansk Deutsch Español Euskara فارسی Français 한국어 Italiano עברית Latviešu Magyar Nederlands 日本 語 Norsk Norsk nynorsk Polski Português Русский Suomi Svenska Українська Tiếng Việt 中文 Edit links This page was last edited on 24 October 2017, at 17 : 57. 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Question: what was the magnitude of the 1964 alaska earthquake
Answer: 9.2 megathrust