Collaborative Research: RAPID: Capturing the Elgin-Lugoff earthquake swarm with a dense nodal array

这个RAPID项目涉及在南卡罗来纳州Elgin-Lugoff地震群序列的震中区域部署86个Smartsolo 5Hz节点。该序列始于2021年12月27日，震级(M) 3.3，发生在背景地震活动性相对较低的地区。这一序列似乎分几期发生，有时由m3 +事件引发，间隔长达数月。虽然它们发生在古老的东部山前断层系统，但对地震的仔细研究表明，大多数事件发生在断层系统之间。在这一点上，我们仍然不清楚是什么驱动了这次地震群，以及它将持续多久。这个部署是及时的，因为这个序列仍在进行中，没有很快结束的迹象。此外，在距离蜂群几公里的范围内只部署了一个监测站。这样的台站分布不足以提供地震群期间微震活动的详细的高分辨率探测/重新定位，而这是更好地破译地震群序列的时空演变及其物理机制所必需的。此外，本次部署收集的地震数据将用于构建当地地下结构的速度模型。准确的地震模型对于开发用于地震危险性评估和圈定断层位置的地面运动模型至关重要。来自佐治亚理工学院和南卡罗来纳大学的多达15名本科生/研究生将参与节点部署。数据将通过IRIS数据管理中心提供。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This RAPID project involves a seismic deployment of 86 Smartsolo 5Hz nodes to the epicenter region of the ongoing Elgin-Lugoff earthquake swarm sequence in South Carolina. This sequence started with a magnitude (M) 3.3 on December 27, 2021, in a region with relatively low background seismicity. This sequence appears to occur in several episodes, sometimes initiated by M 3+ events, and has up to months of gaps in between. While they occurred along the ancient Eastern Piedmont Fault System, a close examination of the earthquakes reveals that most of the events occurred in between the fault system. At this point, it is still not clear what is the driving force for this earthquake swarm and how long it will last.This deployment is timely, because this sequence is still ongoing, with no signs of ending soon. In addition, only one station was deployed within a few kilometers of the swarm. Such station distribution is not sufficient enough to provide a detailed high-resolution detection/relocation of microseismicity during an earthquake swarm, which are needed for better deciphering the spatio-temporal evolutions of the swarm sequence and their physical mechanisms. In addition, the seismic data collected in this deployment will be used to construct a velocity model of the local subsurface structure. Accurate seismic models are crucial particularly for developing ground motion models for seismic hazard assessment and delineating faultlocations. Up to 15 undergraduate/graduate students from both Georgia Tech and University of South Carolina will be involved in the nodal deployment. Data will be made available through the IRIS Data Management Center.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.