文件名称：systematic compilation of
文件大小：1.68MB
文件格式：PDF
更新时间：2014-11-18 10:36:52
precursor
A survey of published scientific literature was undertaken to identify and catalog observed earthquake precursors.The earthquake precursors selected for analysis included electric and magnetic fields, gas emissions,groundwater level changes, temperature changes, surface deformations, and seismicity. For each of theseprecursors, the published scientific literature was searched to document the statistics of each reported earthquakeprecursor (spatial extent, time, duration, amplitude, signal/noise ratio), to analyze dependence of theobservable for each precursor on earthquake magnitude, and to explore proposed physical models to explaineach earthquake precursor. Some general characteristics were observed for these precursory phenomena. First,the largest amplitude precursory anomalies tend to occur before the largest magnitude earthquakes. Also, thenumber of precursory anomalies tends to increase the closer in time to the occurrence of the earthquake.Finally, the precursory anomalies tend to occur close to the eventual epicenter of the earthquake. In general, thephysical models indicate that all of the precursory phenomena are related to deformation that occurs near thefault prior to the main earthquake. While the models provide plausible physical explanations for the precursors,there are many free parameters in the models that are poorly resolved.