Monitoring the Approach to Criticality Using Regional Seismicity

这项研究是对圣安德烈亚斯断层前兆地震活动调查工作的延伸，发现自1906年以来所有震级大于6.5的地震事件之前都有地震能量释放的幂律增加。这项工作旨在解决地壳是否处于自组织临界状态的连续状态或大地震是否会产生远离临界的局部漂移的问题。如果后者成立，地震预报可能是可能的，因为随后回归临界的方法预计具有确定性，可观察的特征，如前兆地震活动的增加。这项工作将把前兆地震活动研究扩展到全球目录，在数据允许的情况下，研究剪切带和俯冲带中尽可能多的大事件。这项研究是国家减少地震危害计划的一个组成部分。＊＊＊

9725379 Sammis This research is an extension of work that investigated precursory seismicity along the San Andreas Fault and found that all events since 1906 with magnitude greater than 6.5 were preceded by a power-law increase in seismic energy release. The work aims to address the question of whether the crust is in a continuous state of self-organized criticality or whether large earthquakes produce local excursions away from criticality. If the latter holds true, earthquake forecasting may be possible since the subsequent approach back toward criticality is expected to have deterministic, observable characteristics such as the increase in precursory seismicity. This work will extend the precursory seismicity study to the worldwide catalogs, studying as many large events in both shear zones and subduction zones as the data allows. This research is a component of the National Earthquake Hazard Reduction Program. ***