Anomalies in continuous GPS data as precursors of 15 large earthquakes in Western North America during 2007-2016

摘要

The preparation processes of large earthquake may start several or dozens of days before its actual occurrence. As scholars have observed the links between stationary GPS measurements of ground deformation and the occurrence of large earthquake, the continuous GPS data can be used as tools to identify such preparation processes. A method based on Martingale theory is proposed to extract the anomalies in continuous GPS data prior to 15 large earthquakes in western North America during 2007-2016. The precursory information of the anomalies for the corresponding earthquake is evaluated by using Molchan(,)s error diagram. The results validate that the extracted anomalies have a strong correlation with the short-impending large earthquakes. This demonstrates that changes of ground deformation recorded by GPS contain useful information for earthquake forecasting and the proposed method therefore can be used to improve the prediction of large earthquakes.