Merging lab and field data: seismic indicators of earthquake nucleation

合并实验室和现场数据：地震成核的地震指标

基本信息

批准号：
1645163
负责人：
Gregory McLaskey
金额：
$ 21.5万
依托单位：
Cornell University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-05-01 至 2020-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1645163&HistoricalAwards=false
关键词：
Merging lab field data seismic

项目摘要

Earthquakes begin deep within the earth in a poorly understood process known as earthquake nucleation. Much of our understanding of earthquake nucleation is the result of laboratory rock mechanics experiments, but the laboratory-based models are difficult to apply to observations of natural earthquakes. This project brings together field recordings of earthquakes in Oklahoma and large scale laboratory experiments with the goal of linking both sets of data to identify a physical model of earthquake nucleation that can be tested with seismic observations. Larger than most laboratory experiments, the meter-sized samples are instrumented with a laboratory version of a seismic network, so a more direct comparison can be made to seismic recordings made in the field. A better understanding of the earthquake nucleation process will help us understand why earthquakes occur, how to avoid them, and how to better interpret seismic clues such as foreshocks.The most commonly cited model of earthquake nucleation proposes that earthquakes do not begin instantaneously but are preceded by slow slip. However, the model's seismic implications are unclear, and its applicability to crustal conditions is debated. The proposed laboratory experiments allow the direct observation of the nucleation of magnitude negative three earthquakes under controlled conditions. The meter-sized sample is instrumented with arrays of sensors that can record both slow slip and any seismic signatures of the nucleation process including magnitude negative seven foreshocks and initial P-wave seismograms. This project will then rigorously interpret seismic data collected in north-central Oklahoma within the context of physical models of earthquake initiation and seismic/aseismic interactions developed in the laboratory.

地震从地球深处开始，其过程被称为地震成核，人们对此知之甚少。我们对地震成核的大部分理解是实验室岩石力学实验的结果，但基于实验室的模型很难应用于自然地震的观测。该项目汇集了俄克拉荷马州地震的现场记录和大规模实验室实验，目的是将两组数据联系起来，以确定可以通过地震观测进行测试的地震成核物理模型。米级样本比大多数实验室实验都要大，配备了实验室版本的地震网络，因此可以与现场地震记录进行更直接的比较。更好地了解地震成核过程将有助于我们理解地震发生的原因、如何避免地震以及如何更好地解释前震等地震线索。最常被引用的地震成核模型认为，地震不是立即开始的，而是先于地震发生的。通过缓慢滑动。然而，该模型的地震影响尚不清楚，其对地壳条件的适用性也存在争议。所提出的实验室实验允许在受控条件下直接观察震级负三级地震的成核。米大小的样本配备了传感器阵列，可以记录慢滑移和成核过程的任何地震特征，包括震级负七次前震和初始 P 波地震图。然后，该项目将在实验室开发的地震引发和地震/地震相互作用的物理模型的背景下严格解释在俄克拉荷马州中北部收集的地震数据。