Collaborative Research: Aftershock Imaging with Dense Arrays (AIDA) for the August 23, 2011, Mw 5.8, Virginia earthquake aftershock sequence

合作研究：2011 年 8 月 23 日，Mw 5.8，弗吉尼亚地震余震序列的密集阵列余震成像 (AIDA)

• 批准号: 1160666
• 负责人: John Hole
• 金额: $ 2.33万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2012-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1160666&HistoricalAwards=false
• 关键词: Collaborative; Research; Aftershock; Imaging; Dense

This RAPID supports post-seismic deployment of novel high density seismic arrays usinginstruments from the Earthscope Flexible Array provided by IRIS/PASSCAL to investigate theMw 5.8 Virginia earthquake of August 23, 2011. This event had a NE-striking reverse faulting focalmechanism, a hypocentral depth of 6 km (USGS), and occurred in a previously recognized seismicregion known as the ?Central Virginia Seismic Zone?. This event passes with ca. 15 km of a NW-SEoriented deep seismic reflection profile contracted in 1981 by the USGS, providing a rare opportunityto link seismicity to deep structure in the eastern U.S. The preliminary hypocentral estimate suggeststhat the earthquake occurred within a complex zone of east-dipping reflections that define animbricated Paleozoic thrust sheet of the central Appalachian Piedmont that is underlain by Grenvillebasement at a depth of ca. 9 km.By merging the technologies of earthquake location with high resolution structural imaging, this experiment seeks to demonstrate how aftershocks can be exploited by both passive and active seismic techniques to identify seismogenic structures at depth as well as energy propagation characteristics for a region where both types of information are either rare or non-existent. The recording experiment constitutes a prototype for imaging earthquake processes and associated structures with unprecedented resolution by exploiting a new generation recording technologies. If the data proves as rich as expected, this experiment may well establish a new protocol for future aftershocks studies.

该 RAPID 支持使用 IRIS/PASSCAL 提供的 Earthscope 柔性阵列中的仪器对新型高密度地震阵列进行震后部署，以调查 2011 年 8 月 23 日发生的弗吉尼亚州 5.8 级地震。该事件具有 NE 走向的反向断层震源机制，震源深度为 6 公里 (USGS)，发生在先前公认的称为“弗吉尼亚中部”的地震区。 地震带？此事件经过约。美国地质勘探局于 1981 年签订了 15 公里的西北-东南向深部地震反射剖面图，为将地震活动与美国东部深层结构联系起来提供了难得的机会。初步震源估计表明，地震发生在东倾反射的复杂区域内，该反射区域定义了阿巴拉契亚山麓中部的叠瓦状古生代冲断片，其下方为格伦维尔基底。 在大约深度9公里。通过将地震定位技术与高分辨率结构成像相结合，该实验旨在演示如何通过被动和主动地震技术来利用余震来识别深度发震结构以及两种类型信息稀有或不存在的区域的能量传播特征。该记录实验通过利用新一代记录技术，构建了以前所未有的分辨率对地震过程和相关结构进行成像的原型。如果数据如预期的那样丰富，该实验很可能为未来的余震研究建立一个新的协议。