The
1964 Alaska earthquake, known also as the
Great Alaskan Earthquake, began at 5:36 P.M. AST on Friday, March 27, 1964. Across south-central Alaska, ground fissures, collapsing buildings, and
tsunamiA tsunami or tidal wave is a series of water waves caused by the displacement of a large volume of a body of water, such as an ocean or a large lake. Tsunamis are a frequent occurrence in Japan; approximately 195 events have been recorded...
s directly caused about 131 deaths. This Alaskan
megathrust earthquakeMegathrust earthquakes occur at subduction zones at destructive plate boundaries , where one tectonic plate is forced under another. Due to the shallow dip of the plate boundary, which causes large sections to get stuck, these earthquakes are among the world's largest, with moment magnitudes ...
is known commonly as
The Good Friday Earthquake because of the date of its occurrence.
Lasting nearly five minutes, it was the most powerful recorded
earthquakeAn earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves...
in
U.S.The United States of America is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D...
and
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere...
n history, and the second most powerful ever measured by seismograph. It had a magnitude of 9.2, at the time making it the second largest earthquake in the recorded history of the world.
The powerful earthquake produced earthquake liquefaction in the region. Ground fissures and failures caused major structural damage in several communities, much damage to property and several landslides. Anchorage sustained great destruction or damage to many
inadequately engineeredEarthquake engineering is the study of the behavior of buildings and structures subject to seismic loading. It is a subset of both structural and civil engineering.The main objectives of earthquake engineering are:...
houses, buildings, and infrastructure (paved streets, sidewalks, water and sewer mains, electrical systems, and other man-made equipment). Two hundred miles southwest, some areas near Kodiak were permanently raised by . East of Anchorage, areas around the head of Turnagain Arm near Portage dropped , requiring reconstruction and fill to raise the Seward Highway above the new high tidemark. In Prince William Sound, a
tsunamiA tsunami or tidal wave is a series of water waves caused by the displacement of a large volume of a body of water, such as an ocean or a large lake. Tsunamis are a frequent occurrence in Japan; approximately 195 events have been recorded...
destroyed the village of
ChenegaChenega is a census-designated place on Evans Island in the Valdez-Cordova Census Area in the U.S. state of Alaska. Located in Prince William Sound, the CDP consists of the Chugach Alutiiq village of Chenega Bay, which was established only after the Good Friday Earthquake destroyed the original...
, killing 23 of the 68 people who then lived there; survivors out-ran the wave, climbing to high ground. Post-quake tsunamis severely affected Valdez, Whittier, Seward, Kodiak, and other Alaskan Communities, as well as people and property in British Columbia, Oregon, and California. Tsunamis also caused damage in Hawaii and Japan.
The earthquake
At 5:36 p.m. Alaska Standard Time (3:36 a.m. March 28, 1964
UTCCoordinated Universal Time is a time standard based on International Atomic Time with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation...
), a fault between the
PacificThe Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean, and at 103 million square kilometres, the largest of all tectonic plates....
and
North AmericanThe North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...
plates ruptured near
College FjordCollege Fjord is a fjord located in the northern sector of Prince William Sound in the U.S. state of Alaska. The fjord contains five tidewater glaciers , five large valley glaciers, and dozens of smaller glaciers, most named after renowned East Coast colleges...
in Prince William Sound. The
epicenterThe epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...
of the earthquake was , 12.4 mi (20 km) north of
Prince William SoundPrince William Sound is a sound off the Gulf of Alaska on the south coast of the U.S. state of Alaska. It is located on the east side of the Kenai Peninsula. Its largest port is Valdez, at the southern terminus of the Trans-Alaska Pipeline System...
, 78 miles (125 km) east of
AnchorageAnchorage is the largest city in the U.S. state of Alaska. With an estimated 279,243 municipal residents in 2008 , the city constitutes more than 40 percent of the state's total population; only New York has a higher percentage of residents who live in the state's largest...
and 40 miles (64 km) west of
ValdezValdez is a city in Valdez-Cordova Census Area in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 4,020. The city is one of the most important ports in Alaska.- Economy :...
. The focus occurred at a depth of approximately 15.5 mi (25 km). Ocean floor shifts created large
tsunamiA tsunami or tidal wave is a series of water waves caused by the displacement of a large volume of a body of water, such as an ocean or a large lake. Tsunamis are a frequent occurrence in Japan; approximately 195 events have been recorded...
s (up to 70 feet (20 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 displacementIn tectonics, vertical displacement is the shifting of land in a vertical direction, resulting in a permanent change in elevation.Two types of vertical displacement are uplift, an increase in elevation, and subsidence, a decrease in elevation....
of up to 38 feet (11.5 m) occurred, affecting an area of 100,000 miles² (250,000 km²) within
AlaskaAlaska is the largest state of the United States by area; it is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait. Approximately...
.
Type of fault
The Alaska Earthquake was a subduction zone earthquake (
megathrust earthquakeMegathrust earthquakes occur at subduction zones at destructive plate boundaries , where one tectonic plate is forced under another. Due to the shallow dip of the plate boundary, which causes large sections to get stuck, these earthquakes are among the world's largest, with moment magnitudes ...
), caused by an oceanic plate sinking under a continental plate. It was a reverse fault caused by a compressional force. This caused much of the uneven ground.
Death toll, damage and casualties
Various sources indicate that about 131 people died as a result of the earthquake: nine during the earthquake itself, 106 from subsequent tsunamis in
AlaskaAlaska is the largest state of the United States by area; it is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait. Approximately...
and 16 from tsunamis in
OregonOregon ) is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and
CaliforniaCalifornia is the most populous state in the United States, and the third largest by land area, after Alaska and Texas; it is also the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...
. Property damage was estimated at over $300 million ($ in current U.S. dollars).
Anchorage area
Most damage occurred in
AnchorageAnchorage is the largest city in the U.S. state of Alaska. With an estimated 279,243 municipal residents in 2008 , the city constitutes more than 40 percent of the state's total population; only New York has a higher percentage of residents who live in the state's largest...
, 75 mi (120 km) northwest of the
epicenterThe epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...
. Nine people were killed, the only deaths directly attributed to the earthquake. Anchorage was not hit by tsunamis, but
downtownDowntown is a term primarily used in North America to refer to a city's core or central business district, usually in a geographical, commercial, and community sense....
Anchorage was heavily damaged, and parts of the city built on sandy bluffs overlying "Bootlegger Cove
clayClay is a naturally occurring material composed primarily of fine-grained minerals. Clay deposits are mostly composed of clay minerals, a subtype of phyllosilicate minerals, which impart plasticity and harden when fired or dried; they also may contain variable amounts of water trapped in the...
" near Cook Inlet, most notably the Turnagain neighborhood, suffered
landslideA landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
damage. 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 concrete control tower at Anchorage International Airport was not engineered to withstand earthquake activity and collapsed, killing one employee .
The hamlets of
GirdwoodGirdwood is an unincorporated year-round ski resort community within the Municipality of Anchorage in the U.S. state of Alaska. It lies in a valley in the Chugach Mountains near the end of the Turnagain Arm of Cook Inlet, 38 miles southeast of Anchorage proper.It is surrounded by seven permanent...
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. About 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 SoundPrince William Sound is a sound off the Gulf of Alaska on the south coast of the U.S. state of Alaska. It is located on the east side of the Kenai Peninsula. Its largest port is Valdez, at the southern terminus of the Trans-Alaska Pipeline System...
,
Kenai PeninsulaThe Kenai Peninsula is a large peninsula jutting from the southern coast of Alaska in the United States. The name Kenai is probably derived from Kenayskaya, the Russian name for Cook Inlet, which borders the peninsula to the west.-Geography:...
, and
Kodiak IslandKodiak Island is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the United States and the 80th largest island in the world, with an...
areas, especially the major ports of
SewardSeward is a city in Kenai Peninsula Borough in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 3,016....
,
WhittierWhittier is a city in the Valdez-Cordova Census Area in the U.S. state of Alaska. As of the 2000 census, the population was 182. The city is also a port for the Alaska Marine Highway.-Geography:...
and
KodiakKodiak is one of 7 communities and the main city on Kodiak Island in Kodiak Island Borough in the U.S. state of Alaska. All commercial transportation between the entire island and the outside world goes through this city either via ferryboat or airline...
were heavily damaged by a combination of seismic activity, subsidence, post-quake tsunamis and/or earthquake-caused
fireFire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....
s.
ValdezValdez is a city in Valdez-Cordova Census Area in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 4,020. The city is one of the most important ports in Alaska.- Economy :...
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
ChenegaChenega is a census-designated place on Evans Island in the Valdez-Cordova Census Area in the U.S. state of Alaska. Located in Prince William Sound, the CDP consists of the Chugach Alutiiq village of Chenega Bay, which was established only after the Good Friday Earthquake destroyed the original...
and
AfognakAfognak was an Alutiiq village on the island of Afognak in Kodiak Island Borough, Alaska, United States. It was located on Afognak Bay on the southwest coast of the island, north of Kodiak Island.- History :...
, were destroyed or damaged. The earthquake caused the Cold-War era ballistic missile detection radar of
Clear Air Force StationClear Air Force Station is a United States Air Force Station located 5 miles south of Anderson, Alaska, USA, northeast of Mount McKinley, and southwest of Fairbanks. Located at this base is the 13th Space Warning Squadron, a part of the 21st Space Wing at Peterson Air Force Base and NORAD...
to go offline for six minutes, the only unscheduled interruption in its operational history. Near Cordova, the
Million Dollar BridgeThe Miles Glacier Bridge, also known as the Million Dollar Bridge, was built in the early 1900s fifty miles from Cordova in what is now the U.S. state of Alaska. It is a multiple-span Pennsylvania-truss bridge which completed a railroad line for the Copper River and Northwestern Railway, built by...
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 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 ColumbiaPrince Rupert is a port city in the province of British Columbia, Canada. It is the land, air, and water transportation hub of British Columbia's North Coast, and home to some 12,815 people .-History:...
, just south of the
Alaska PanhandleThe Alaska Panhandle, sometimes referred to as Southeast Alaska, is the southeastern portion of the U.S. state of Alaska, which lies west of the northern half of the Canadian province of British Columbia. The majority of the panhandle's area is part of the Tongass National Forest, the United...
, about three hours after the quake. The tsunami then reached
TofinoTofino tofino, located within the Ancestral territory of the Tla'o'qui'aht Nation, is a village of about 1,650 residents on the west coast of Vancouver Island, in British Columbia, Canada, located at the western terminus of Highway 4, on the tip of the Esowista Peninsula, at the southern edge of...
, on the exposed west coast of
Vancouver IslandVancouver Island is a large island in British Columbia, Canada, one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794....
, and traveled up a
fjordGeologically, a fjord is a long, narrow inlet with steep sides, created in a valley carved by glacial activity.-Formation:Fjords are formed when a glacier cuts a U-shaped valley by abrasion of the surrounding bedrock. Many such valleys were formed during the recent ice age...
to hit
Port AlberniPort Alberni is a city located in the province of British Columbia in Canada. It is the seat of the Alberni-Clayoquot Regional District. The city has a total population of 17,743, and the census agglomeration area a total of 25,396....
twice, washing away 55 homes and damaging 375 others. The towns of
Hot Springs CoveHot Springs Cove, formerly Refuge Cove, is an unincorporated settlement on Sydney Inlet on the west side of the Openit Peninsula in the western Clayoquot Sound region of the West Coast of Vancouver Island, located near the natural feature also known by that name, which refers to Ramsay Hot Springs...
,
ZeballosZeballos is a village located on the northwest coast of Vancouver Island in British Columbia, Canada. Originally founded by gold-seeking Spanish explorers, Zeballos is now known for its ecotourism and sport fishing.-Location and geography:...
, and Amai also saw damage. The damage in British Columbia was estimated at $10 million Canadian ($65 million in 2006 Canadian dollars, or $56 million in 2006 U.S. dollars).
Elsewhere
Twelve people were killed by the tsunami in
Crescent City, CaliforniaCrescent City is the county seat and only incorporated city in Del Norte County, California. Named for the crescent-shaped stretch of sandy beach south of the city, the city had a total population of 4,006 in the 2000 census with an estimated population of 7,300 , which includes inmates at Pelican...
, while four children were killed on the Oregon coast at
Beverly Beach State ParkBeverly Beach State Park is a state park in the U.S. state of Oregon located five miles north of Newport. It is a full R.V. hookup camping area with showers, bathrooms, beach access, and a meeting hall where evening interpretive programs take place. The park also has tent areas, as well as yurts...
. Other towns along the U.S.
Pacific NorthwestThe Pacific Northwest is a region in western North America, bound by the Pacific Ocean to the west. Always included are the U.S. states of Washington and Oregon, and the Canadian province of British Columbia...
and
HawaiiHawaii is the newest of the 50 U.S. states , and is the only state made up entirely of islands. It occupies most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of Australia...
were damaged. Minor damage to boats reached as far south as
Los AngelesLos Angeles is the second largest city in the United States, the largest city in the state of California and the Western United States, with a population of 3.83 million within its administrative limits on a land area of...
.
As the entire planet vibrated as a result of the quake, minor effects were felt worldwide. Several fishing boats were sunk in
LouisianaLouisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
, and water sloshed in wells in
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
.
Aftershocks
Over 10,000 aftershocks were recorded following the main shock. In the first day alone, eleven major aftershocks were recorded with a magnitude greater than 6.0. Nine more occurred over the next three weeks. It was not until eighteen months later that the aftershocks were no longer noticed.
Lasting impacts
The earthquake and tsunamis had a variety of impacts on the land value in the area. Real estate appraiser and crisis consultant
Randall BellRandall Bell is the author of Strategy 360: 10 Steps for Creating a Complete Game Plan for Business & Life and the textbook Real Estate Damages....
writes in his book
Real Estate Damages, "Some homes located off the coastline now enjoy outstanding oceanfront views, and as a result of the tragedy their values were enhanced. Although the same risk for another tidal wave exists today as in 1964, a $60 million ocean research and aquarium facility began construction in 1996 on lower-risk areas of the coast."
Discussing
Valdez, AlaskaValdez is a city in Valdez-Cordova Census Area in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 4,020. The city is one of the most important ports in Alaska.- Economy :...
, Bell notes, "The entire town suffered a significant loss, through either the cost of destroyed buildings or the cost of relocating to the new town site. Only the few homes and structures that exist near the old town site suffer from market resistance, as they sell for significant discounts because of the very real danger of a recurrence. The moving of entire towns is not an isolated incident. A village was damaged by the earthquake and tidal waves and was moved to an entirely new island, Evens Island."
General references
External links