An earthquake preminilary measuring 6.6 magnitude on the Richter scale jolted an area bordering Minxian and Zhangxian counties, Dingxi city, Northwest China's Gansu province at 07:45 am, July 22.
The epicenter, with a depth of 20 km, was monitored at 34.521 degrees north latitude and 104.23 degrees east longitude.
Four aftershocks measuring 3.0 to 3.9 magnitude on the Richter scale hit the region in 30 minutes.