Complex Fault Geometry of the 2020 Mww 6.5 Monte Cristo Range, Nevada, Earthquake Sequence
Abstract
On 15 May 2020 an Mww 6.5 earthquake occurred beneath the Monte Cristo Range in the Mina Deflection region of western Nevada. Rapid deployment of eight temporary seismic stations enabled detailed analysis of its productive and slowly decaying aftershock sequence (p=0.8), which included ~18,000 autodetected events in 3.5 months. Double-difference, waveform-based relative relocation of 16,714 earthquakes reveals a complex network of faults, many of which cross the inferred 35-km-long east–northeast-striking, left-lateral mainshock rupture. Seismicity aligns with left-lateral, right-lateral, and normal mechanism moment tensors of 128 of the largest earthquakes. The mainshock occurred near the middle of the aftershock zone at the intersection of two distinct zones of seismicity. In the western section, numerous subparallel, shallow, north-northeast-striking faults form a broad flower-structure-like fault mesh that coalesces at depth into a near-vertical, left-lateral fault. We infer the near-vertical fault to be a region of significant slip in the mainshock and an eastward extension of the left-lateral Candelaria fault. Near the mainshock hypocenter, seismicity occurs on a northeast-striking, west-dipping structure that extends north from the eastern Columbus Salt Marsh normal fault. Together, these two intersecting structures bound the Columbus Salt Marsh tectonic basin. East of this intersection and the mainshock hypocenter, seismicity occurs inmore »
- Authors:
-
[1];
[2];
[2];
[3];
- Univ. of Tulsa, Tulsa, OK (United States)
- Univ. of Nevada, Reno, NV (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1783915
- Report Number(s):
- LLNL-JRNL-814983
Journal ID: ISSN 0895-0695; 1024008
- Grant/Contract Number:
- AC52-07NA27344
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Seismological Research Letters
- Additional Journal Information:
- Journal Volume: 92; Journal Issue: 3; Journal ID: ISSN 0895-0695
- Publisher:
- Seismological Society of America
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 58 GEOSCIENCES
Citation Formats
Ruhl, Christine J., Morton, Emily A., Bormann, Jayne M., Hatch-Ibarra, Rachel, Ichinose, Gene, and Smith, Kenneth D. Complex Fault Geometry of the 2020 Mww 6.5 Monte Cristo Range, Nevada, Earthquake Sequence. United States: N. p., 2021.
Web. doi:10.1785/0220200345.
Ruhl, Christine J., Morton, Emily A., Bormann, Jayne M., Hatch-Ibarra, Rachel, Ichinose, Gene, & Smith, Kenneth D. Complex Fault Geometry of the 2020 Mww 6.5 Monte Cristo Range, Nevada, Earthquake Sequence. United States. https://doi.org/10.1785/0220200345
Ruhl, Christine J., Morton, Emily A., Bormann, Jayne M., Hatch-Ibarra, Rachel, Ichinose, Gene, and Smith, Kenneth D. Wed .
"Complex Fault Geometry of the 2020 Mww 6.5 Monte Cristo Range, Nevada, Earthquake Sequence". United States. https://doi.org/10.1785/0220200345. https://www.osti.gov/servlets/purl/1783915.
@article{osti_1783915,
title = {Complex Fault Geometry of the 2020 Mww 6.5 Monte Cristo Range, Nevada, Earthquake Sequence},
author = {Ruhl, Christine J. and Morton, Emily A. and Bormann, Jayne M. and Hatch-Ibarra, Rachel and Ichinose, Gene and Smith, Kenneth D.},
abstractNote = {On 15 May 2020 an Mww 6.5 earthquake occurred beneath the Monte Cristo Range in the Mina Deflection region of western Nevada. Rapid deployment of eight temporary seismic stations enabled detailed analysis of its productive and slowly decaying aftershock sequence (p=0.8), which included ~18,000 autodetected events in 3.5 months. Double-difference, waveform-based relative relocation of 16,714 earthquakes reveals a complex network of faults, many of which cross the inferred 35-km-long east–northeast-striking, left-lateral mainshock rupture. Seismicity aligns with left-lateral, right-lateral, and normal mechanism moment tensors of 128 of the largest earthquakes. The mainshock occurred near the middle of the aftershock zone at the intersection of two distinct zones of seismicity. In the western section, numerous subparallel, shallow, north-northeast-striking faults form a broad flower-structure-like fault mesh that coalesces at depth into a near-vertical, left-lateral fault. We infer the near-vertical fault to be a region of significant slip in the mainshock and an eastward extension of the left-lateral Candelaria fault. Near the mainshock hypocenter, seismicity occurs on a northeast-striking, west-dipping structure that extends north from the eastern Columbus Salt Marsh normal fault. Together, these two intersecting structures bound the Columbus Salt Marsh tectonic basin. East of this intersection and the mainshock hypocenter, seismicity occurs in a narrow, near-vertical, east-northeast-striking fault zone through to its eastern terminus. At the eastern end, the aftershock zone broadens and extends northwest toward the southern extension of the northwest-striking, right-lateral Petrified Springs fault system. The eastern section hosts significantly fewer aftershocks than the western section, but has more moment release. We infer that shallow aftershocks throughout the system highlight fault-fracture meshes that connect mapped fault systems at depth. Here, comparing earthquake data with surface ruptures and a simple geodetic fault model sheds light on the complexity of this recent M 6.5 Walker Lane earthquake.},
doi = {10.1785/0220200345},
journal = {Seismological Research Letters},
number = 3,
volume = 92,
place = {United States},
year = {Wed Apr 07 00:00:00 EDT 2021},
month = {Wed Apr 07 00:00:00 EDT 2021}
}
Search WorldCat to find libraries that may hold this journalWorks referenced in this record:
Data Release for the 2014 National Seismic Hazard Model for the Conterminous U.S.
dataset, January 2019
- Shumway, Allison M.
- U.S. Geological Survey