摘要
态矢量是一种中短期地震预测方法 ,通常在大地震发生之前,态矢量时间序列会发生明显的异常变化.在此基础上,进一步尝试根据震前应力场分布,提高态矢量的地震临界敏感性,震前库仑应力分布采用地震断层位错模型将滑移量反向滑移的方法计算,2008年汶川地震震前的态矢量研究表明,采用库仑应力算法得到的时间序列前兆变化更明显,对目标地震的预测更明确.此外,尝试利用GPS连续形变观测替代传统的地震目录计算态矢量,对美国南加州2004年Parkfield地震的研究发现,得到的时间序列具有更好的连续性,能够清晰分辨出震前出现的异常变化.因此,结合多样的地震观测资料,针对不同地区的活动构造特征,可以灵活运用态矢量为未来地震的发生提供信息和约束.
State vector is a kind of short-to-intermediate-term earthquake prediction method. Before occurrence of large earthquake the state vector time series usually changed anomalously. In this study, we first to enhance the critical sensitivity of the state vector method with an area within which the tectonic stress change would mostly affect the Coulomb Stress on a potential seismogenic fault of a future event. The Coulomb Stress change before a hypothetical earthquake is calculated based on a simple back slip dislocation model of the event. Retrospective test of this new algorithm on the 2008 Ms8. 0 Wenchuan earthquake shows remarkable enhancement of the state vector precursory anomaly. We then try to use GPS-derived displacement data instead of the traditional earthquake catalog to calculate the state vector, and applied the approach to test the 2004 Parkfield earthquake in Southern California. Results show that the state vector time series is more continuous, which can clearly identify the anomalous changes occur before the earthquake. Therefore, with a variety of earthquake observation data input, we can use the state vector method to provide information and constraints for future earthquake occurrence in any tectonically active regions.
出处
《地球物理学进展》
CSCD
北大核心
2011年第1期32-40,共9页
Progress in Geophysics
基金
科技部国际科技合作项目"华北地区地震构造与地震监测预测新方法合作研究"(2010DFB20190)
国家自然科学基金项目(40704007)联合资助
关键词
态矢量
地震前兆
库仑应力
GPS
state vector, precursor of earthquake, coulomb stress, GPS
