Observations and analysis of the quasi-electrostatic field anomaly before the 6.2 earthquake in Zhangbei

A Ms6.2 earthquake occurred at 11:50 on Jan. 10th 1998, the the strongest earthquake in China's Hebei province since the Tangshan Earthquake in 1976. Prior to the earthquake, the authors recorded obvious abnormal signals roughly at the same time from two observatory stations, one at the Handan Station in Hebei province, and the other at Sishui Station in Shandong province. The obtained materials can provide very good information on the study of the quasi-static field.