1949 Queen Charlotte earthquake
Encyclopedia
The Queen Charlotte Islands earthquake of 1949 was a magnitude
8.1 interplate earthquake
that struck the sparsely populated Queen Charlotte Islands
and the Pacific Northwest
coast on August 22, 1949. It is one of the world's greatest earthquakes. The main shock epicenter
began in the ocean bottom just offshore the rugged coast of Graham Island
. It ruptured along the Queen Charlotte Fault
both northward and southward more than 500 km (311 mi). Shaking was felt throughout British Columbia
, parts of Washington, Oregon
, Alberta
, the Yukon
, and Alaska
. No deaths were reported in this earthquake.
This earthquake, larger than the 1906 San Francisco earthquake
, is Canada's largest earthquake recorded by seismometer
s. However, the greatest earthquake in Canadian history was the 1700 Cascadia earthquake, a megathrust earthquake
that occurred along the Pacific Northwest coast from Northern California
to southwestern British Columbia which reached magnitude 9 on the Richter magnitude scale
.
, which forms part of the boundary between the Pacific
and North American plate
s. This fault runs from northern Vancouver Island
, west of the Queen Charlotte Islands, up to the Gulf of Alaska
. The earthquake ruptured the fault for a distance more than 500 km (311 mi).
s and other damage. Chimneys tumbled, and an oil tank at Cumahewa Inlet collapsed. In the service community of Terrace
, away on the mainland, cars were bounced around, and standing on the street was described as "like being on the heaving deck of a ship at sea". In the port city of Prince Rupert
, windows were destroyed and buildings swung.
Surface wave magnitude
The surface wave magnitude scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements in Rayleigh surface waves that travel primarily along the uppermost layers of the earth...
8.1 interplate earthquake
Interplate earthquake
An interplate earthquake is an earthquake that occurs at the boundary between two tectonic plates. If one plate is trying to move past the other, they will be locked until sufficient stress builds up to cause the plates to slip relative to each other...
that struck the sparsely populated Queen Charlotte Islands
Queen Charlotte Islands
Haida Gwaii , formerly the Queen Charlotte Islands, is an archipelago on the North Coast of British Columbia, Canada. Haida Gwaii consists of two main islands: Graham Island in the north, and Moresby Island in the south, along with approximately 150 smaller islands with a total landmass of...
and the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
coast on August 22, 1949. It is one of the world's greatest earthquakes. The main shock epicenter
Epicenter
The 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...
began in the ocean bottom just offshore the rugged coast of Graham Island
Graham Island
Graham Island is the largest island in the Haida Gwaii archipelago , lying off the coast of British Columbia, Canada. It is separated only by a narrow channel from the other principal island of the group, Moresby Island Graham Island is the largest island in the Haida Gwaii archipelago (formerly...
. It ruptured along the Queen Charlotte Fault
Queen Charlotte Fault
The Queen Charlotte Fault is an active transform fault, located between the North American Plate and the Pacific Plate, Canada's equivalent of the San Andreas Fault. The Queen Charlotte Fault forms a triple junction on its south with the Cascadia subduction zone and the Explorer Ridge...
both northward and southward more than 500 km (311 mi). Shaking was felt throughout British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, parts of Washington, Oregon
Oregon
Oregon 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...
, Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, the Yukon
Yukon
Yukon is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River. The word Yukon means "Great River" in Gwich’in....
, and Alaska
Alaska
Alaska is the largest state in 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...
. No deaths were reported in this earthquake.
This earthquake, larger than the 1906 San Francisco earthquake
1906 San Francisco earthquake
The San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, California, and the coast of Northern California at 5:12 a.m. on Wednesday, April 18, 1906. The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.9; however, other...
, is Canada's largest earthquake recorded by seismometer
Seismometer
Seismometers are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources...
s. However, the greatest earthquake in Canadian history was the 1700 Cascadia earthquake, a megathrust earthquake
Megathrust earthquake
Megathrust 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 ...
that occurred along the Pacific Northwest coast from Northern California
Northern California
Northern California is the northern portion of the U.S. state of California. The San Francisco Bay Area , and Sacramento as well as its metropolitan area are the main population centers...
to southwestern British Columbia which reached magnitude 9 on the Richter magnitude scale
Richter magnitude scale
The expression Richter magnitude scale refers to a number of ways to assign a single number to quantify the energy contained in an earthquake....
.
Geology
The 1949 Queen Charlotte Islands earthquake was caused by a rupture on the Queen Charlotte FaultQueen Charlotte Fault
The Queen Charlotte Fault is an active transform fault, located between the North American Plate and the Pacific Plate, Canada's equivalent of the San Andreas Fault. The Queen Charlotte Fault forms a triple junction on its south with the Cascadia subduction zone and the Explorer Ridge...
, which forms part of the boundary between the Pacific
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
and North American plate
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan 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...
s. This fault runs from northern Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is 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...
, west of the Queen Charlotte Islands, up to the Gulf of Alaska
Gulf of Alaska
The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
. The earthquake ruptured the fault for a distance more than 500 km (311 mi).
Subsequent damage
Although nobody was killed in this earthquake, people and animals were knocked off their feet and there were landslideLandslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
s and other damage. Chimneys tumbled, and an oil tank at Cumahewa Inlet collapsed. In the service community of Terrace
Terrace, British Columbia
Terrace is a city on the Skeena River in British Columbia, Canada. The Kitselas people, a tribe of the Tsimshian Nation, have lived in the Terrace area for thousands of years. The community population fell between 2001 and 2006 from 12,109 with a regional population of 19,980 to 11,320 and...
, away on the mainland, cars were bounced around, and standing on the street was described as "like being on the heaving deck of a ship at sea". In the port city of Prince Rupert
Prince Rupert, British Columbia
Prince 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:...
, windows were destroyed and buildings swung.
See also
- List of earthquakes in Canada
- 1700 Cascadia earthquake
- 1906 San Francisco earthquake1906 San Francisco earthquakeThe San Francisco earthquake of 1906 was a major earthquake that struck San Francisco, California, and the coast of Northern California at 5:12 a.m. on Wednesday, April 18, 1906. The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.9; however, other...