Mapping the fractures associated with the magnitude 6.4 Ridgecrest earthquake foreshock from July 4, 2019

Thomas A. Shea, Alba M. Rodriguez Padilla, & Michael E. Oskin

Published August 11, 2021, SCEC Contribution #11256, 2021 SCEC Annual Meeting Poster #061 (PDF)

The 2019 Ridgecrest earthquake sequence generated a surface rupture, part of which was along a previously unknown fault perpendicular to the Little Lake Fault Zone. Using high-resolution airborne images collected by the National Center for Airborne Laser Mapping, we mapped a section of the surface rupture associated with this newly discovered fault, which ruptured during the Mw 6.4 foreshock on July 4. This section of the foreshock has a very localized rupture with minor secondary fracturing. The primary rupture strand is subtle and disappears at times as the rupture goes blind. Many of the secondary fractures we mapped are very subtle and below the resolution of airborne lidar data and other geodetic datasets, highlighting the importance of high-resolution imagery in rupture mapping. This map may be used for probabilistic rupture hazard assessment for future earthquakes in the Eastern California Shear Zone.

Key Words
Ridgecrest, foreshock, surface deformation

Citation
Shea, T. A., Rodriguez Padilla, A. M., & Oskin, M. E. (2021, 08). Mapping the fractures associated with the magnitude 6.4 Ridgecrest earthquake foreshock from July 4, 2019. Poster Presentation at 2021 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Geology