Inferred seismic fault associated with the 1998 M = 6.2 Zhangbei-Shanyi earthquake, Hebei Province, China

The shallow, Ms = 6.2, 1998 Zhangbei-Shanyi earthquake that affected the no rthwest region of Beijing, China, occurred at the intersection of two activ e fault zones, located on the north and east edges of the Ordos tableland. A detailed map of the intensity distribution of damaged building shows that the most damaged area was centered 8 to 10 km away from the epicenter, inc luding an ellipsoidal region with a strike of NNE, where more than 70 to 90 % of buildings were destroyed. Many chimneys and gate pillars were broken a nd fell toward the SSE-SSW direction in the western side of the most damage d area and to the NNE-NNW direction in the eastern side. Aftershocks were a lso concentrated in the most damaged area. It is inferred that the boundary of the downfallen direction change is the surface trace of the seismic fau lt. Based on the seismic data, the distribution of damaged buildings, and t he downfallen directions of 70 chimneys and Sate pillars, it is identified that the seismic fault is a thrust fault striking NNE and dipping 40 degree s to 50 degrees northwest with a large right-lateral displacement component .