An earthquake measuring 7.8 on the Richter scale jolted Wenchuan County, Sichuan Province at 2:28 p.m. on May 12. The quake was felt throughout Sichuan and almost all damage from it occurred in that province.

At present, epicenters in Sichuan are concentrated on eight major earthquake belts or areas. The earthquake that jolted Wenchuan May 12 occurred on one just active belt among the eight.