The 1970 Colombia earthquake occurred in
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
on July 31.
Details and aftermath
The shock killed one person and injured several others. Because it was a
deep-focus earthquake A deep-focus earthquake in seismology (also called a plutonic earthquake) is an earthquake with a hypocenter depth exceeding 300 km. They occur almost exclusively at convergent boundary, convergent boundaries in association with subducted ocean ...
, shaking occurred over an extensive area, including
San Juan San Juan, Spanish for Saint John, may refer to:
Places Argentina
* San Juan Province, Argentina
* San Juan, Argentina, the capital of that province
* San Juan, Salta, a village in Iruya, Salta Province
* San Juan (Buenos Aires Underground), ...
,
Bogotá
Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish period and between 1991 and 2000, is the capital city of Colombia, and one of the larges ...
,
Caracas
Caracas (, ), officially Santiago de León de Caracas, abbreviated as CCS, is the capital and largest city of Venezuela, and the center of the Metropolitan Region of Caracas (or Greater Caracas). Caracas is located along the Guaire River in the ...
,
Buenos Aires
Buenos Aires ( or ; ), officially the Autonomous City of Buenos Aires ( es, link=no, Ciudad Autónoma de Buenos Aires), is the capital and primate city of Argentina. The city is located on the western shore of the Río de la Plata, on South ...
, and
São Paulo
São Paulo (, ; Portuguese for 'Saint Paul') is the most populous city in Brazil, and is the capital of the state of São Paulo, the most populous and wealthiest Brazilian state, located in the country's Southeast Region. Listed by the GaWC a ...
; it was felt as far north as
Mexico City
Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...
.
[ Its depth forestalled more serious casualties,]aftershock
In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousand ...
s.
The depth of the earthquake prompted scientists in South America to install seismometer networks focused on long-period earthquakes
Prediction of volcanic activity, or volcanic eruption forecasting, is an interdisciplinary monitoring and research effort to predict the time and severity of a volcano's eruption. Of particular importance is the prediction of hazardous eruptions t ...
.[ Until the ]1994 Bolivia earthquake
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.
The Harvard CMT Project assigned it a focal depth of 647 km and a magnitude ...
, the 1970 Colombia earthquake was famous among seismologists as the largest deep earthquake.[Russakoff, Ekstrom, and Tromp, pg. 20423.]
Analysis
A study completed by Dziewonski and Gilbert Gilbert may refer to:
People and fictional characters
* Gilbert (given name), including a list of people and fictional characters
*Gilbert (surname), including a list of people
Places Australia
* Gilbert River (Queensland)
* Gilbert River (South ...
(1974) determined that the earthquake had featured isotropic compression, or an increase in density near the rupture point similar to an implosion;[ They also claimed that the compression had been initiated 80 seconds before the actual earthquake's short-period shaking. Many studies have reached differing conclusions including a dearth of isotropic movement, and many scientists feel that resolution created errors in Dziewonski and Gilbert's findings.][Russakoff, Ekstrom, and Tromp, pg. 20424.] In 1997, Russakoff, Ekstrom, and Tromp reassessed their findings utilizing more advanced equipment that factored in shear wave splitting
Shear wave splitting, also called seismic birefringence, is the phenomenon that occurs when a Polarization (waves), polarized shear wave enters an anisotropic medium (Fig. 1). The incident shear wave splits into two polarized shear waves (Fig. 2). ...
and coupling (the measure of how tightly locked two sides of a fault or plate are) and confirmed that there was very little isotropic compression.[
]
See also
*List of earthquakes in 1970
This is a list of earthquakes in 1970. Only magnitude 6.0 or greater earthquakes appear on the list. Lower magnitude events are included if they have caused death, injury or damage. Events which occurred in remote areas will be excluded from the ...
*List of earthquakes in Colombia
This is a list of earthquakes in Colombia. Colombia is a seismically active country and has a large seismic risk in many areas of its territory due to its location at the boundaries of the Malpelo, Panama, Caribbean, North Andes (where most ea ...
References
Bibliography
*
External links
*
{{Tectonism in Colombia, state=expanded
1970 earthquakes
1970 in science
1970 in Colombia
1970
Events
January
* January 1 – Unix time epoch reached at 00:00:00 UTC.
* January 5 – The 7.1 Tonghai earthquake shakes Tonghai County, Yunnan province, China, with a maximum Mercalli intensity scale, Mercalli intensity of X (''Extrem ...
July 1970 events in South America