Earthquake Prediction Research in China: Zhangbei M_S=6.2 Earthquake on January 10, 1998

Abstract

A national conference on seismic trend in China (NCSTC) is held at the beginning of every year by State Seismological Bureau (SSB), which distributes mid — term earthquake prediction, especially for the seismic trend in the next year and the most possible risk regions, which is called special risk regions for earthquake (SRREs). This lays a good base for the scientists in SSB to screen the future earthquakes and to do short-term earthquake prediction.

An earthquake (M_s6.2) took place between Zhangbei and Shangyi counties, Hebei province on Jan. 10, 1998, which caused serious damage and heavy casualties in the two counties and was also broadly felt in Beijing. The epicenter is in (41°06’N, 114° 18’E) with depth of 10 Km. Seismic anomalies appeared 2 years earlier in the relative region, for example, a significant seismic belt emerged with M>4 earthquakes, regional shock activity increased and b value turned to be lower than before. Several days to several months before the main shock, the precursors were also found, such ground tilt in Chicheng and Zhangjiakou, geoelectric resistivity in Yangyuan and Baochang, water level in Yanqing, geomagnetic field and low — point displacement in Huhehaote and Beijing.

The boundary region of Shanxi Province, Hebei Province and Inner Mongolia, including Zhangbei county, has been taken as a SRRE of M56 in NCSTC in 1997 and 1998. In spite of the clear mid — term prediction, short — term to imminent earthquake prediction failed.