T52A-07
An MW-based Historical Earthquake Catalog for Mainland China
Friday, 18 December 2015: 11:50
304 (Moscone South)
Jia Cheng1,2, Yufang Rong2, Harold Magistrale2, Guihua Chen3 and Xiwei Xu4, (1)CENC China Earthquake Networks Center, Beijing, China, (2)FM Global Research, Norwood, MA, United States, (3)Institute of Geology, China Earthquake Administration, Beijing, China, (4)Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
Abstract:
China has a nearly 3,000-year long earthquake record. As a step to develop seismic hazard maps for mainland China, we compiled a homogeneous MW-based historical earthquake catalog. We started from an MS-based Chinese catalog spanning from 780 B.C. to present. We compared MS from the catalog with Mw for common earthquakes in the ISC-GEM and GCMT catalogs, and derived MS- MW regression relationships using orthogonal least square method. We derived regression relationships for different time periods considering the following factors: 1) Chinese seismograph network density has been improved with time; 2) the methodology for determining earthquake magnitude and location in the Chinese catalog has changed through time; and 3) different seismographs were used in different times. We also derived separate regression relationships for small and large events since the parameters of large events are usually reevaluated in the Chinese catalog. For events included in the ISC-GEM or GCMT catalogs, we use the location and magnitude from those catalogs. For other events, we used the location from the Chinese catalog and the converted MW. The final catalog has about 5,000 earthquakes of MW 4.5 and larger. The catalog is more complete for eastern China than western China because eastern China has much longer history of human settlement. Key words
Earthquake catalog in mainland China, Surface magnitude, Moment magnitude, orthogonal regression.
