Teleseismic Studies of 'Quiet' Earthquakes and Other Events Of Anomalously Long Duration

这项研究是在美国国家科学基金会之前的一项资助下取得的进展，其中制定了用于检测和表征异常持续时间长的地震的新技术。一份新的10年正态激励事件目录已经完成，可以在全球范围内系统地识别慢震。这导致了一种新型地震的发现，这种地震激发自由振荡，但不会产生在长周期或短周期地震图上可观察到的波群，称为“安静地震”。这些异常缓慢的事件可能是快速破裂或正常地震的前兆。这项研究将更精确地定义慢破裂，并研究它们是否是大破坏事件的前兆，从而为短期地震预测提供一种手段。这项研究是国家减少地震危害计划的一个组成部分。

This research follows advances developed under a prior NSF grant where new techniques were formulated for the detection and characterization of earthquakes with anomalously long duration. A new 10-year catalog of normal-mode excitation events has been made that allows the systematic identification of slow earthquakes on a global scale. This has led to the discovery of a new type of earthquake which excites free oscillations but does not generate wave groups observable on long-period or short- period seismograms, called "quiet earthquakes." These unusually slow events may be precursory to fast ruptures, or normal earthquakes. This research will more precisely define the slow ruptures and investigate whether they are precursory to large damaging events and thus provide a means of short-term earthquake prediction. This research is a component of the National Earthquake Hazard Reduction Program.