High-Resolution Imaging of the Elgin-Lugoff Earthquake Swarm Sequence in South Carolina Using a Dense Seismic Nodal Array
Description:
Earthquake swarms are characterized by closely-clustered seismic events in space and time, without a single main shock, and they often occur along plate boundaries with ample volatiles or fluids. In comparison, swarms at intraplate regions are rather unique, especially in the Southeast United States where background seismicity is typically low. A prolonged earthquake swarm sequence started on December 27, 2021, beginning with a magnitude 3.3 earthquake near Elgin and Southwest Lugoff in South Carolina (SC). Up to now, 81 microearthquakes have been located in this region, with the largest magnitude of 3.6 occurring on June 29, 2022. These earthquakes occurred near the Eastern Piedmont Fault System (EPFS), but upon closer examination, most events were found to occur across rather than along the EPFS (Howard et al., 2023). This swarm sequence was widely felt in the broader region of SC, and offers a rare opportunity to study physical mechanisms of earthquake swarms in intraplate regions. In October 2022, 86 SmartSolo nodes were deployed in a 7 km x 7 km area right on top of the swarm sequence, with one site co-located with a broadband seismometer JKYD. This deployment aims to capture near-field observations of the sequence in high definition for up to 4 months. The data collected from this deployment can be used to detect additional smaller earthquakes not listed in the existing catalog, and the relocated catalog can reveal spatial-time evolution of the swarm and underlying forces driving this swarm. Preliminary results from this nodal deployment, including comparisons of the nodal recordings and the co-located broadband recording, will be presented in the meeting.
Session: Tectonics and Seismicity of Stable Continental Interiors
Type: Oral
Date: 4/19/2023
Presentation Time: 05:15 PM (local time)
Presenting Author: Zhigang Peng
Student Presenter: No
Invited Presentation:
Authors
Zhigang Peng Presenting Author Corresponding Author zpeng@gatech.edu Georgia Institute of Technology |
Lindsay Chuang lchuang@gatech.edu Georgia Institute of Technology |
Phuc Mach pmach3@gatech.edu Georgia Institute of Technology |
Dan Frost dfrost@seoe.sc.edu University of South Carolina |
Scott Howard howards@dnr.sc.gov South Carolina Geological Survey |
Scott White swhite@geol.sc.edu University of South Carolina |
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High-Resolution Imaging of the Elgin-Lugoff Earthquake Swarm Sequence in South Carolina Using a Dense Seismic Nodal Array
Category
Tectonics and Seismicity of Stable Continental Interiors