Current Understanding of Intraplate Seismicity and Surface Deformation Associated with the August 9th, 2020 Mw 5.1 Earthquake Near Sparta, North Carolina

Wednesday, 28 October 2020
1:30 PM - 5:30 PM
Auditorium

NEW PERSPECTIVES ON A NEW FAULT - HOW THE USE OF DRONES AIDED IN THE CHARACTERIZATION OF THE LITTLE RIVER FAULT

Program: Late Breaking Session
Time: 3:05 PM – 3:25 PM

Authors

Abstract

Following the 9 August, 2020 Mw 5.1 earthquake near Sparta, North Carolina, the North Carolina Geological Survey’s rapid response efforts included drone deployments for reconnaissance flights and mapping purposes. We used a DJI Mavic 2 Pro®, a low-cost, consumer-grade UAS (Unmanned Aerial System) platform to make real-time observations and capture imagery where field geologists had located or suspected ground surface changes associated with the newly discovered Little River Fault (LRF). We used acquisition parameters designed to facilitate development of 2D orthomosaic images for plan-view mapping purposes and 3D digital elevation models for characterization and identification of the LRF and its associated features such as fault splays, en echelon fracture sets, and shaking-related ground cracks. We used Drone2Map® GIS software to produce cm-scale color images and DEMs of the LRF, which lead to the identification of unmapped fault splays, zones of ground rupture, and surface flexures. In one instance, use of the drone identified ground rupture some 200 m from the closest known surface exposure of the LRF, increasing the efficiency of field operations. Coseismic ground rupture lines were mapped using UAS imagery to a degree of accuracy previously unattainable without significant cost and coordination (i.e., fixed wing aircraft surveys). Our ongoing data analyses involve evaluating elevation trends along topographic profiles perpendicular to the mapped fault trace, and comparing these post-earthquake UAS-derived elevation surfaces to pre-earthquake, 1-meter resolution lidar DEMs. We plan to continue advancing our UAS program for the rapid response to geological hazards in the North Carolina Blue Ridge.

Geological Society of America Abstracts with Programs. Vol. 52, No. 6

doi: 10.1130/abs/2020AM-361225

© Copyright 2020 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.