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The January 2001 El Salvador earthquake struck El Salvador on January 13 and February 13, 2001 at 17:33:34 UTC the 7.6 (later estimated to be 7.7 or 7.9)〔 quake struck with the epicenter at 60 miles (100 km) SW of San Miguel, El Salvador (13.04N 88.66W) at a depth of 60 km. At least 944 people were killed, 5,565 injured, 108,261 houses destroyed — with another 169,692 houses damaged — and more than 150,000 buildings were damaged in El Salvador.〔Christian Aid. ("El Salvador Earthquake: Emergency Update 02 Feb 2001" ) (press release), on ReliefWeb.int, February 2, 2001.〕 About 585 of the deaths were caused by large landslides in Santa Tecla and Comasagua. As is often the case after earthquakes in El Salvador, landslides wreaked significant damage. Estimation of the number of slides is difficult because individual scarps conjoin. The total has been reported as high as 16,000, though it is unclear how this figure was arrived at. Damage and injuries occurred in every department of El Salvador, particularly the departments of La Libertad and Usulután. Eight people were killed in Guatemala. The tremor was felt from Mexico City to Colombia.〔(http://neic.usgs.gov/neis/eq_depot/2001/eq_010113/ )〕 An aftershock measuring 5.7 magnitude was felt on January 15, an event not widely reported outside the country until after the February quake, which initially was assessed by the USGS at 5.7 magnitude as well.〔CNN. ("Quake aftershock frightens Salvadorans," ) CNN.com, February 13, 2001.〕 As of February 2, 2001, more than 2,500 aftershocks had hit El Salvador, leading to additional damage and terrorizing the inhabitants. Clean water and sanitation became a matter of grave concern in many areas due to the earthquake's destruction of some $7 million to municipal drinking water systems, and tens of thousands of people were living outdoors in spite of the approaching rainy season (''invierno'').〔 Government and public health organizations warned of the possible spread of disease as desperate people began to scavenge debris piles — some containing severed human limbs — looking for items they could pawn to purchase needed food and other commodities.〔CNN. ("Poor sanitation fuels disease fears in aftermath of Salvador quake," ) CNN.com, January 20, 2001.〕 == Earthquake mechanisms == The earthquakes occurred within the Cocos-Caribbean subduction zone. El Salvador sits atop the western part of the Caribbean plate, where it is overriding (subducting) the Cocos plate. Subduction zones such as this are geologically very complex and produce numerous earthquakes from multiple sources. Shallow intraplate (crustal) earthquakes occur within the crust of the overriding Caribbean plate. Deeper intraplate earthquakes occur within the subducting Cocos plate. The earthquake sequence in the El Salvador region has involved intraplate faulting in both the Cocos and Caribbean plates, with the largest earthquake in the sequence (January 13) occurring in the lower (Cocos) plate. The February 13 earthquake was a strong, shallow intraplate earthquake, occurring within the crust of the overlying Caribbean plate. This earthquake was a strike-slip faulting earthquake, which likely occurred in response to the complicated stresses in the Caribbean plate as it overrides the Cocos plate. It was about 85 km away from the 13 January earthquake and about 30 km shallower. These two earthquakes occurred in two different plates. The occurrence of any large earthquake changes the stresses throughout the surrounding region. Aftershocks occur in response to these changes. Occasionally, other earthquakes will occur in response to the altered regional stresses. While not technically aftershocks, these earthquakes are related, becoming part of a regional earthquake sequence. Another example of a regional earthquake sequence is the 1992 Landers-Big Bear sequence in southern California. The magnitude 7.3 Landers earthquake was followed by the magnitude 6.4 Big Bear earthquake, which occurred on a different fault approximately 36 km away.〔(http://neic.usgs.gov/neis/eq_depot/2001/eq_010213/ )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「January 2001 El Salvador earthquake」の詳細全文を読む スポンサード リンク
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