Rapid deployment of onshore/offshore seismic stations in the North Chile Seismic Gap following the April 2014 M8.2 Pisagua earthquake

2014 年 4 月皮萨瓜 M8.2 地震后，在智利北部地震间隙快速部署陆上/海上地震台

基本信息

批准号：
NE/M005879/1
负责人：
Isabelle Ryder
金额：
$ 6.62万
依托单位：
University of Liverpool
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2014
资助国家：
英国
起止时间：
2014 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FM005879%2F1
关键词：
Rapid deployment onshore offshore seismic

项目摘要

The Peru-Chile subduction zone hosts many large earthquakes. A M8.8 earthquake occurred in northern Chile in 1877, and since then, no major event had re-ruptured the area prior to April 2014. The 500 km-long zone has therefore become known as the "North Chile seismic gap". In late March 2014, many small to moderate earthquakes occurred within this gap. Activity generally migrated slightly northwards. On 2 April 2014, a M8.2 earthquake occurred in the northern part of the preceding cluster, followed by many aftershocks, including a M7.6 event. Aftershock activity continues and, since the rest of the area has not experienced a major earthquake for well over a century, another large event in the area in the near future or medium term cannot be ruled out. In order to measure aftershock activity in the area of the seismic gap that ruptured recently, in addition to any other events that may occur nearby, we propose to install seismometers in the Peruvian coastal region and also offshore Chile. There are two main reasons for doing this. Firstly, the extra networks will dramatically improve station coverage around the seismic gap area, enabling us to generate detailed models of the subduction zone. This will be of great benefit for future analyses of seismic activity in this earthquake-prone area. Secondly, our records of the ongoing seismic activity will enable us to locate aftershocks accurately and infer what type of faulting occurred. This will enable us to build up a very detailed picture of how post-earthquake processes relate to preceding large seismic events.We will also use satellite radar images to construct maps of how the surface of the Earth has moved as a result of the recent seismic activity. These deformation maps can be used in computer models to estimate the location and magnitude of slip that occurred on faults beneath the surface - for instance, on the subduction zone interface, where the mainshock occurred. Essentially we are using surface measurements to infer sub-surface processes.Results from the seismological and satellite components of our project will be integrated to give us an in-depth understanding of the properties and processes occurring in the North Chile seismic gap. For instance, we will look at the spatial relationship between the area that ruptures in major earthquakes and the location of foreshock/aftershock sequences. Another important issue is to identify areas on the subduction zone interface that have not yet slipped, and that could therefore rupture in major earthquakes in the future.

秘鲁-智利俯冲带多次发生大地震。 1877年，智利北部发生了8.8级地震，此后，直到2014年4月，该地区再没有发生过重大地震，这一长达500公里的地带因此被称为“智利北部地震缺口”。 2014年3月下旬，该间隙内发生多起中小地震。活动总体上稍微向北迁移。 2014年4月2日，前一组地震的北部发生了8.2级地震，随后发生了多次余震，其中包括一次7.6级地震。余震活动仍在继续，由于该地区其他地区已有一个多世纪没有经历过大地震，因此不能排除该地区在不久的将来或中期再次发生大地震的可能性。为了测量最近破裂的地震间隙区域的余震活动以及附近可能发生的任何其他事件，我们建议在秘鲁沿海地区和智利近海安装地震仪。这样做有两个主要原因。首先，额外的网络将极大地改善地震间隙区域周围的台站覆盖范围，使我们能够生成俯冲带的详细模型。这对于今后对该地震多发区的地震活动分析将大有裨益。其次，我们对正在进行的地震活动的记录将使我们能够准确定位余震并推断发生的断层类型。这将使我们能够非常详细地了解震后过程与之前的大地震事件的关系。我们还将使用卫星雷达图像来绘制地球表面因最近的地震而如何移动的地图。活动。这些变形图可用于计算机模型中，以估计地表以下断层上发生的滑动的位置和强度 - 例如，在发生主震的俯冲带界面上。本质上，我们正在使用地面测量来推断地下过程。我们项目的地震学和卫星部分的结果将被整合，以使我们深入了解智利北部地震间隙发生的特性和过程。例如，我们将研究大地震中破裂区域与前震/余震序列位置之间的空间关系。另一个重要问题是确定俯冲带界面上尚未滑动的区域，因此可能在未来的大地震中发生破裂。