What Controls Earthquake Size & Occurrence?

地震规模由什么控制

• 批准号: 8720935
• 负责人: Larry Ruff
• 金额: $ 11万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-15 至 1991-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8720935&HistoricalAwards=false
• 关键词: What; Controls; Earthquake; Size; &amp

What controls earthquake size and occurrence? Scientists and non-scientists alike have pondered this question for a longtime. Earthquakes are a complex and wonderous natural phenomenon that unfortunately can also cause great human catastrophes; the hazards range from near-source ground shaking to tsunamis that can strike from across the Pacific Ocean. Plate tectonics provides the framework to explain plate boundary earthquakes as a direct consequence of the plate boundaries, what controls exactly wherean earthquake will occur; how large it will be; and when it will happen? To answer these questions, seismologists must look closer at the plate interface zone. In fact, it is necessary to "look inside" the earthquake rupture areas. Heuristic arguments (plus some direct observations) clearly indicate that the processes and properties of plate interface zones cannot be spatially homogeneous - spatial heterogeneity is required to explain seismicity. A first-order categorization of fault zone heterogeneity is the simple binary classification of strong/weak.The strong regions are "stuck" and accumulate the tectonic strain, to be finally released by rupture in large earthquakes. We call these strong regions asperities. One of the excitingrecent developments in earthquake seismology is that we are now moving from the mere acceptance of spatial heterogeneity to actually mapping the first-order representation of this heterogeneity along plate boundary segments.

是什么控制着地震的规模和发生？科学家和非科学家都已经思考了这个问题很长时间了。地震是一种复杂而奇妙的自然现象，不幸的是，它也可能造成巨大的人类灾难；危害范围从近源地面震动到可能从太平洋对岸袭击的海啸。板块构造提供了一个框架来解释板块边界地震作为板块边界的直接结果，究竟是什么控制了地震将在哪里发生，规模有多大，以及将在何时发生？要回答这些问题，地震学家必须更仔细地研究板块交界区。事实上，有必要对地震破裂区域进行“看一看”。试探性论证(加上一些直接观测)清楚地表明，板块界面带的过程和性质不可能在空间上是同质的--解释地震活动需要空间异质性。断裂带非均质性的一级分类是简单的强/弱二分类。强区被“卡住”，积累构造应变，在大地震中通过破裂最终释放。我们称这些强烈的区域为凹凸不平。地震地震学中一个令人兴奋的最新发展是，我们现在正在从单纯接受空间非均质性转向沿着板块边界区段实际绘制这种非均质性的一阶表示。