Temporal gravity changes before the 2008 Yutian Ms7.3 earthquake  

作　　者：Shen Chongyang Li Hui Sun Shaoan Yang Guangliang Xuan Songbai Tan Hongbo Liu Shaoming 

机构地区：[1]Institute of Seismology, China Earthquake Administration, Wuhan 430071, China [2]Crustal Movement Laboratory, Wuhan 430071, China

出　　处：《Geodesy and Geodynamics》2012年第1期19-26,共8页大地测量与地球动力学（英文版）

基　　金：supported by the National Natural Science Foundation of China(40574012)

摘　　要：Based on the data of the repeated gravity observation network in Chinese mainland since 1998, we analyzed the temporal changes of regional gravity field before the 2008 Yutian Ms7.3 earthquake. The result shows some mid-to-long term （two to ten years） changes during the earthquake＇ s preparation. Notable fea- tures are a gravity increase lasting several years and a relatively large-scaled gradient zone of gravity change, the former indicating a continuous energy accumulation and the latter a possible location of seismic rupture. These gravity changes showed a trend of increase-accelerated increase-decelerated increase, similar to that of the Tangshan Ms7.8 earthquake in 1976. The maximum accumulated gravity change related to the earthquake reached 200 × 10 -8 ms -2.Based on the data of the repeated gravity observation network in Chinese mainland since 1998, we analyzed the temporal changes of regional gravity field before the 2008 Yutian Ms7.3 earthquake. The result shows some mid-to-long term （two to ten years） changes during the earthquake＇ s preparation. Notable fea- tures are a gravity increase lasting several years and a relatively large-scaled gradient zone of gravity change, the former indicating a continuous energy accumulation and the latter a possible location of seismic rupture. These gravity changes showed a trend of increase-accelerated increase-decelerated increase, similar to that of the Tangshan Ms7.8 earthquake in 1976. The maximum accumulated gravity change related to the earthquake reached 200 × 10 -8 ms -2.

关 键 词：Yutian earthquake GRAVIMETRY dynamic change SEISMOGENY 

分 类 号：P315.7[天文地球—地震学] TQ336.1[天文地球—固体地球物理学]