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 - 智利俯冲带有许多大地震。 1877年，智利北部发生了M8.8地震，从那时起，没有重大事件在2014年4月之前重新爆发。因此，500公里长的区域已被称为“北智利地震鸿沟”。 2014年3月下旬，在这一差距内发生了许多小到中等地震。活动通常向北略微迁移。 2014年4月2日，上一群集群的北部发生了M8.2地震，随后发生了许多余震，包括M7.6事件。余震活动仍在继续，由于该地区其他地区没有经历过一个多世纪以来的主要地震，因此在不久的将来或中期的另一个大事件不能排除。为了测量最近发生的地震间隙区域的余震活动，除了附近可能发生的任何其他事件外，我们还建议在秘鲁沿海地区和辣椒岛货币库中安装地震仪。这样做的主要原因有两个。首先，额外的网络将大大改善地震间隙区域周围的车站覆盖范围，从而使我们能够生成俯冲带的详细模型。这对于在易于地震的地区进行地震活动的将来分析将有很大的好处。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地定位余震，并推断发生了什么类型的断层。这将使我们能够建立一个非常详细的图片，描述了地震后过程如何与大型地震事件有关。我们还将使用卫星雷达图像来构建地球表面如何由于最近的地震活动而移动的地图。这些变形图可在计算机模型中使用，以估计在表面下方的断层上发生的滑移的位置和大小 - 例如，在俯冲区接口（发生的俯冲区接口）上。从本质上讲，我们正在使用表面测量来推断地下过程。从我们项目的地震学和卫星组成部分中进行的反应将整合，以使我们对北辣椒地震差距中发生的性质和过程有深入的了解。例如，我们将研究大地震中破裂的区域与前壳/余震序列的位置之间的空间关系。另一个重要的问题是确定俯冲带界面上尚未滑倒的区域，因此将来可能会在主要地震中破裂。