Update on the Seismicity and Tectonics of the 2021-2022 Elgin-Lugoff, South Carolina Earthquake Sequence
Description:
On December 27, 2021 a M=3.3 earthquake started a nearly year-long swarm of felt events centered near the towns of Elgin and Lugoff, South Carolina, ~30 km NE of Columbia, the state capital. Prior to December 27, 2021 event, we can find no evidence of previously reported earthquakes in this area. As of December 10, 2022 there have been 82 events (80 felt) in this swarm, including five M 3+ events widely felt in the Midlands of South Carolina. These events appear to be associated with a reactivated cross fault within the Paleozoic Eastern Piedmont Fault System (EPFS). In this region the EPFS is recognized via magnetic anomalies as it is covered by a thin veneer of coastal plain sediments (0-150 feet thick). The initial events of this sequence are relatively poorly located, with the closest seismic station being >30 km away. Soon after the start of the sequence (December 31, 2021) a new station (BARN) was installed 3-5 kilometers SE of the swarm. In addition, on April 17, 2022 a Raspberry Shake 3D station (R3A5D) was installed ~10 kilometers WSW of the swarm. We have begun analyzing this earthquake sequence in more detail, especially for events occurring after April 17, 2022 when both new stations were operating. Our initial attempts at relocating events in the swarm suggest it is more spatially concentrated than the network solutions suggest; in particular, the two events offset to the south relocate within the main swarm. We also note that there are many smaller events clearly recorded on the nearest station (BARN), some of which are potentially locatable. We will present our latest results on the number, location, and geometry of the Elgin-Lugoff earthquake sequence.
Session: Tectonics and Seismicity of Stable Continental Interiors
Type: Oral
Date: 4/19/2023
Presentation Time: 05:00 PM (local time)
Presenting Author: Steven Jaume
Student Presenter: No
Invited Presentation:
Authors
Steven Jaume Presenting Author Corresponding Author jaumes@cofc.edu College of Charleston |
Scott Howard howards@dnr.sc.gov South Carolina Geological Survey |
Scott White swhite@geol.sc.edu University of South Carolina |
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Update on the Seismicity and Tectonics of the 2021-2022 Elgin-Lugoff, South Carolina Earthquake Sequence
Category
Tectonics and Seismicity of Stable Continental Interiors