Tsnunami Earthquakes and Interplate Coupling at Subduction Zones

海啸地震与俯冲带的板间耦合

• 批准号: 9316528
• 负责人: Hiroo Kanamori
• 金额: $ 14.34万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316528&HistoricalAwards=false
• 关键词: Tsnunami; Earthquakes; Interplate; Coupling; Subduction

9316528 Kanamori This research is to study the characteristics of tsunami- producing earthquakes to determine the role of sediment subduction at plate margins and the resulting influence on the mechanism of subduction-zone earthquakes. Detailed investigations of the 1992 Nicaragua earthquake and other subduction-zone earthquakes will be done to determine the source characteristics and spectra in relation to the sediment structure near the epicenter of the respective events. In addition to traditional seismic analysis, the research will involve use of a newly recognized long-period phase, the W phase, which arrives between the P and S waves. The traditional tsunami warning system is based on the location and the magnitude of the earthquake. Unfortunately, because of past instrumental limitations, the traditional system uses 20-second surface-wave magnitude for warning purposes. However, for slow earthquakes such as the Nicaragua event, the 20-second surface-wave magnitude does not represent the true size of the earthquake. At periods longer than 100 seconds, the tsunami potential would have been better recognized. This research is a component of the National Earthquake Hazard Reduction Program. ***

本研究旨在研究产生海啸的地震特征，以确定板块边缘沉积物俯冲作用及其对俯冲带地震发生机制的影响。将对1992年尼加拉瓜地震和其他俯冲带地震进行详细调查，以确定与各自事件震中附近沉积物结构有关的震源特征和频谱。除了传统的地震分析外，该研究还将涉及使用新发现的长周期相位，即位于P波和S波之间的W相位。传统的海啸预警系统是基于地震的位置和震级。不幸的是，由于过去仪器的限制，传统的系统使用20秒的表面波量级来预警。然而，对于像尼加拉瓜地震这样的缓慢地震，20秒的表面波震级并不能代表地震的真实规模。如果周期超过100秒，海啸的可能性就会得到更好的识别。这项研究是国家减少地震危害计划的一个组成部分。＊＊＊