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Usgs data on the sichuan quake

The USGS has a summary of relevant information on the Sichuan quake, such as the areas that felt the quake the hardest and the populations of those cities.

For a technical explanation of what happened:

The Sichuan earthquake of May 12, 2008, occurred as the result of motion on a northeast striking reverse fault or thrust fault on the northwestern margin of the Sichuan Basin. The earthquake's epicenter and focal-mechanism are consistent with it having occurred as the result of movement on the Longmenshan fault or a tectonically related fault. The earthquake reflects tectonic stresses resulting from the convergence of crustal material slowly moving from the high Tibetan Plateau, to the west, against strong crust underlying the Sichuan Basin and southeastern China.

On a continental scale, the seismicity of central and eastern Asia is a result of northward convergence of the India plate against the Eurasia plate with a velocity of about 50 mm/y. The convergence of the two plates is broadly accommodated by the uplift of the Asian highlands and by the motion of crustal material to the east away from the uplifted Tibetan Plateau.

The northwestern margin of the Sichuan Basin has previously experienced destructive earthquakes. The magnitude 7.5 earthquake of August 25, 1933, killed more than 9,300 people.

There was another more recent quake too.

Overall, structures in this region are vulnerable to earthquake shaking, though some resistant structures exist. A magnitude 6.4 earthquake struck the Sichuan, China region on August 23, 1976 (UTC), with estimated population exposures of 1,500 at intensity IX or greater and 5,700 at intensity VIII, resulting in 41 deaths.

(Above quoted text courtesy of the USGS.)

A little more interesting are the reactions of Chinese bloggers to the quake:

One famous Chinese blogger, the television reporter Luqiu Luwei, raised a few questions on her blog: Why were so many middle school students among the dead from the disaster? What did that say about the quality of those school buildings? Official media reported that hundreds of students died in the Sichuan earthquake, as they were pinned under the collapsing buildings.

Another blogger, Zeng XianNan, was suspicious about whether the quake could have been predicted based on seismic activity. "I saw the Sichuan Net news quoting Sichuan Earthquake Bureau official Deng Chang Wen saying before the earthquake no forecast indicated any macro anomolies," Zeng wrote. "If this was true, then it means that our technology is not strong enough. But wasn't [it true] that we have successfully forecast earthquakes before? If it were the case that it was detected but reporting was delayed, how would [they] explain that?"

In Baidu Post Bar, a popular Internet forum, thousands of people around China were posting their accounts on what was happening in their region, as if it could make them feel safer and better. Elsewhere online, three college students in Chengdu, the home of 11 million people, shot a short video during the earthquake and posted it on Tudou, a major user-generated video-sharing site in China. The video was later removed, but it was not clear why. (Tudou means potato in English.)

(h/t Instapundit)

earthquake.