四川大地震 Sichuan Earthquake 2008 [=?
What kind of plate movement caused this earthquake?
- 1 decade agoFavorite Answer
The earthquake had a magnitude of 8.0 Ms and 7.9 Mw. The epicenter was in Wenchuan County, Ngawa Tibetan and Qiang Autonomous Prefecture, 80 km west/northwest of the provincial capital city of Chengdu, with its main tremor occurring at 14:28:01.42 CST (06:28:01.42 UTC), on Monday May 12, 2008 lasting for around 3 minutes.
According to a study by the China Earthquake Administration (CEA), this earthquake occurred along the Longmenshan fault, a thrust formation along the border of Indo-Australian Plate and Eurasian Plate. Seismic activities concentrated on its mid-fracture (known as Yingxiu-Beichuan fracture). The rupture lasted close to 120 sec, with the majority of energy released in the first 80 sec. Starting from Wenchuan, the rupture propagated at an average speed of 3.1 kilometers per second 49° toward north east, rupturing a total of about 300 km. Maximum displacement amounted to 9 meters. The epicenter was deeper than 10 km.
In a United States Geological Survey (USGS) study, preliminary rupture models of the earthquake indicated displacement of up to 9 meters along a fault approximately 240 km long by 20 km deep. The earthquake generated deformations of the surface greater than 3 meters and increased the stress (and probability of occurrence of future events) at the northeastern and southwestern ends of the fault. On May 20, USGS seismologist Tom Parsons warned that there is "high risk" of a major M>7 aftershock over the next weeks or months.
Japanese seismologist Yuji Yagi said that the earthquake occurred in two stages: "The 155-mile Longmenshan Fault tore in two sections, the first one ripping about seven yards, followed by a second one that sheared four yards." Yagi's data also showed that the earthquake lasted about two minutes and released 30 times the energy of the Great Hanshin earthquake of 1995 in Japan, which killed over 6,000 people. He pointed out that the shallowness of the epicenter and the density of population greatly increased the severity of the earthquake. Teruyuki Kato, a seismologist at the University of Tokyo, said that the seismic waves of the quake traveled a long distance without losing their power because of the firmness of the terrain in central China.. According to reports from Chengdu, the capital of Sichuan province, the earthquake tremors lasted for "about two or three minutes".
- 4 years ago
I'm not sure completely. But I think China may be slowly positively changing (may be, not totally sure). HOwever, I think the Beijing Olympics plays a big part. With all the negative publicity over the Olympics and the scrutiny China is under, they allowed in aid and let media coverage occur. Not only is it the right thing to do (which is one big reason, b/c it is the right thing to do), also, it won't make them look bad by helping. In addition, they don't want to do the same mistake that Myanmar did, which was a really horrible mistake. Myanmar refused to let in much aid and took much of the aid to themselves (the generals, rich persons). Moreover, I think China has learned from previous problems- Tangshan and Tiananmen- and has gotten better. (slowly getting better, I share same view as Nicholas Kristof- NYT writer) .. Yes they aren't perfect, but they've improved.
- 1 decade ago