The Contrast Study of Precursor Anomalies before the M_S 8. 0 Wenchuan Earthquake  

作　　者：Chen Lide Fu Hong 

机构地区：[1]Earthquake Administration of Yunnan Province, Kunming 650224, China

出　　处：《Earthquake Research in China》2012年第3期365-376,共12页中国地震研究（英文版）

基　　金：sponsored by the National Basic Research Program (973 Program),China (2008CB425700)

摘　　要：The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan M_S 8. 0 earthquake is less than that of the Menglian earthquake. The number of anomalies and stations associated with the Wenchuan earthquake increased in the early stage of the short-term range,as opposed to the later period for the Menglian and Lijiang earthquakes. Most of the medium term anomalies occurred two to three years before the Wenchuan earthquake,when the number of anomaly stations and items was eleven,and a great change appeared in the observation values in about half of the stations ( items ) . However,for the Menglian earthquake,medium term anomalies happened one to two years before the earthquake, the number of abnormal stations and items reached 20,and a sharp change appeared in the observation values six months to one year before the earthquake in about 30 percent of the stations or items. In the epicenter and the nearby area,the macroscopic abnormalities started 3 years before the Wenchuan earthquake and lasted intermittently until 1 month before the earthquake. Within 2 percent of the total area of the province,the macroscopic abnormalities accounted for 30 to 50 percent of the total number of anomalies of the Province. For the Xingtai,Tangshan,Haicheng,Songpan earthquakes,the macroscopic anomalies started two to three months before,or on the very day of the earthquakes. The common feature of the precursors between the Wenchuan and other strong earthquakes is the appearance of tremendous changes in a certain number of observation values of anomalies in the mid and short terms before all these earthquakes.The contrast research results show that the number of items and stations with imminent, short and medium term precursor anomalies for the Wenchuan Ms8.0 earthquake is less than that of the Menglian earthquake. The number of anomalies and stations associated with the Wenchuan earthquake increased in the early stage of the short-term range, as opposed to the later period for the Menglian and Lijiang earthquakes. Most of the medium term anomalies occurred two to three years before the Wenchuan earthquake, when the number of anomaly stations and items was eleven, and a great change appeared in the observation values in about half of the stations （items）. However, for the Menglian earthquake, medium term anomalies happened one to two years before the earthquake, the number of abnormal stations and items reached 20, and a sharp change appeared in the observation values six months to one year before the earthquake in about 30 percent of the stations or items. In the epicenter and the nearby area, the macroscopic abnormalities started 3 years before the Wenchuan earthquake and lasted intermittently until 1 month before the earthquake. Within 2 percent of the total area of the province, the macroscopic abnormalities accounted for 30 to 50 percent of the total number of anomalies of the Province. For the Xingtai, Tangshan, Haicheng, Songpan earthquakes, the macroscopic anomalies started two to three months before, or on the very day of the earthquakes. The common feature of the precursors between the Wenchuan and other strong earthquakes is the appearance of tremendous changes in a certain number of observation values of anomalies in the mid and short terms before all these earthquakes.

关 键 词：Wenehuan MsS. 0 earthquake Precursor anomalies Contrast study 

分 类 号：P315.72[天文地球—地震学] P315.7[天文地球—固体地球物理学]