SEISMIC DANGER DIVISIONS BASED ON HYDROGEOCHEMICAL-TECTONIC CHARACTERISTICS ON THE CONTINENT OF CHINA

Seismic danger zones on the continent of China are distinguished by taking the main indices of hydrogeochemical fields of hot groundwater and mineral groundwater, tectonic framework and tectonic activities and regularity of historical seismic activities as the main criteria for the division, combined with distributions of geophysical fields, ground temperature fields and grouping of regional strata.In this paper the continent of China is divided into six seismic danger regions, 23 danger subregions and 30 danger zones and the main hydrogeochemical and tectonic characteristics in various danger subregions and danger zones are dealt with.The coupling between earthquakes and the hydrogeochemical characteristics and hydrochemical field has been determined through studying the hydrogeochemical characteristics of groundwater and the hydrochemical field and analyzing the tectonic characteristics and activities.This work has great significance for the layout of earthquake and hydrological observation wells and prediction of earthquakes.Through long-term monitoring of the change of the chemical composition of groundwater, a new kind of premonitory information for earthquake prediction may be provided.