Variational characteristics of shear-wave splitting on the 2001 Shidian earthquakes in Yunnan, China  

作　　者：GAO Yuan LIANG Wei DING Xiang XUE Yan CAI Ming-jun LIU Xi-qiang SU You-jin PENG Li-guo 

机构地区：[1]Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China [2]Graduate Schoo1Chinese Academy of Sciences, Beijing 100039,China [3]Earthquake Administration ofYunnan Province, Kunming 650041,China [4]Earthquake Administration of Shandong Province, Jinan 250014, China [5]Center for Comprehensive Surveying,China Earthquake Administration,Beijing 100039,China

出　　处：《Acta Seismologica Sinica(English Edition)》2004年第6期635-641,共7页

基　　金：National Natural Science Foundation of China (40274011, 40074020), MOST (2001BA601B02) and Joint Seismological Science Foundation of China (102068).

摘　　要：In 2001 three earthquakes occurred in Shidian in Yunnan Province, which were the MS=5.2 on April 10, the MS=5.9 on April 12 and the MS=5.3 on June 8. Based on the data from the station Baoshan of Yunnan Telemetry Digital Seismograph Network, the variational characteristics of shear-wave splitting on these series of strong earthquakes has been studied by using the systematic analysis method (SAM) of shear-wave splitting. The result shows the time delays of shear-wave splitting basically increase with earthquake activity intensifying. However the time delays abruptly decrease immediately before strong aftershocks. It accords with the stress relaxation before earthquakes, which was found recently in study on shear-wave splitting. The result suggests it is significant for reducing the harm degree of earthquakes to develop the stress-forecasting on earthquake in strong active tectonic zones and economic developed regions or big cities under the danger of strong earthquakes.In 2001 three earthquakes occurred in Shidian in Yunnan Province, which were the MS=5.2 on April 10, the MS=5.9 on April 12 and the MS=5.3 on June 8. Based on the data from the station Baoshan of Yunnan Telemetry Digital Seismograph Network, the variational characteristics of shear-wave splitting on these series of strong earthquakes has been studied by using the systematic analysis method (SAM) of shear-wave splitting. The result shows the time delays of shear-wave splitting basically increase with earthquake activity intensifying. However the time delays abruptly decrease immediately before strong aftershocks. It accords with the stress relaxation before earthquakes, which was found recently in study on shear-wave splitting. The result suggests it is significant for reducing the harm degree of earthquakes to develop the stress-forecasting on earthquake in strong active tectonic zones and economic developed regions or big cities under the danger of strong earthquakes.

关 键 词：shear-wave splitting temporal change earthquake stress-forecasting Shidian earthquakes SAM analysis 

分 类 号：P315.3+1[天文地球—地震学]