1994 Bolivia earthquake
Encyclopedia
The 1994 Bolivia earthquake occurred on June 9, 1994. The epicenter
was located in a sparsely populated region in the Amazon jungle, about 200 miles from La Paz
.
Harvard assigned it a focal depth of 647 km and a magnitude MW of 8.2, making it the largest earthquake since the Sumbawa earthquake of 1977. It is also the largest earthquake ever recorded with a focal depth greater than 300 km. South America also experienced the second and third largest earthquakes at focal depths greater than 300 km: Colombia, 1970; and northern Peru, 1922.
where it is being pushed beneath the mantle of the South American continent. It shook the ground from Argentina to Canada and its oscillations were the first to be captured on a modern seismic network. Light damage to buildings was felt in Sao Paulo
, Brazil, and Toronto
, Canada.
The quake also destroyed scientists' opinions on deep earthquakes. According to the squeeze theory of earthquakes, pressures and temperatures at the depth of 200 to 400 miles should be so great that rock should not undergo frictional sliding; most geologists believed that the crushing pressures and increasing heat below a certain depth compressed rocks into forms that were denser, creating huge cracks in the Earth's surface. The Bolivian earthquake was 395 miles below sea level and, according to geologist Paul G. Silver, "[the earthquake] looks and acts and talks like these shallow earthquakes. But it shouldn't exist."
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...
was located in a sparsely populated region in the Amazon jungle, about 200 miles from La Paz
La Paz
Nuestra Señora de La Paz is the administrative capital of Bolivia, as well as the departmental capital of the La Paz Department, and the second largest city in the country after Santa Cruz de la Sierra...
.
Harvard assigned it a focal depth of 647 km and a magnitude MW of 8.2, making it the largest earthquake since the Sumbawa earthquake of 1977. It is also the largest earthquake ever recorded with a focal depth greater than 300 km. South America also experienced the second and third largest earthquakes at focal depths greater than 300 km: Colombia, 1970; and northern Peru, 1922.
Description
The rupture was located on the Nazca plateNazca Plate
]The Nazca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction along the Peru-Chile Trench of the Nazca Plate under the South American Plate is largely responsible for the...
where it is being pushed beneath the mantle of the South American continent. It shook the ground from Argentina to Canada and its oscillations were the first to be captured on a modern seismic network. Light damage to buildings was felt in Sao Paulo
São Paulo
São Paulo is the largest city in Brazil, the largest city in the southern hemisphere and South America, and the world's seventh largest city by population. The metropolis is anchor to the São Paulo metropolitan area, ranked as the second-most populous metropolitan area in the Americas and among...
, Brazil, and Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
, Canada.
The quake also destroyed scientists' opinions on deep earthquakes. According to the squeeze theory of earthquakes, pressures and temperatures at the depth of 200 to 400 miles should be so great that rock should not undergo frictional sliding; most geologists believed that the crushing pressures and increasing heat below a certain depth compressed rocks into forms that were denser, creating huge cracks in the Earth's surface. The Bolivian earthquake was 395 miles below sea level and, according to geologist Paul G. Silver, "[the earthquake] looks and acts and talks like these shallow earthquakes. But it shouldn't exist."