TY - JOUR
T1 - Late Holocene rupture history of the Ash Hill fault, Eastern California Shear Zone, and the potential for seismogenic strain transfer between nearby faults
AU - Regalla, Christine
AU - Kirby, Eric
AU - Mahan, Shannon
AU - McDonald, Eric
AU - Pangrcic, Hannah
AU - Binkley, Amanda
AU - Schottenfels, Emily
AU - LaPlante, Aubrey
AU - Sethanant, Israporn
AU - Lynch, Emerson M.
N1 - Funding Information:
This project has been supported in part by the Southern California Earthquake Center (SCEC Award #18048), GSA student grants, and the NAU Duebendorfer‐Barnes Endowment (Regalla); NSF EarthScope award EAR 0643096 (Kirby); US Army Research Office, Terrestrial Science Program (McDonald); and USGS FEDMAP program, Western Basin and Range – Eastern California Shear Zone Geologic Mapping Project (Mahan). Funding information
Funding Information:
Data supporting the results and interpretations in this paper are presented in the online Supporting Information. DSMs generated by this study are publicly available at https://opentopography.org/ . LiDAR DEMs utilized in this study are based on services provided to the Plate Boundary Observatory by NCALM ( http://www.ncalm.org ). PBO is operated by UNAVCO for EarthScope ( http://www.earthscope.org ) and supported by the National Science Foundation (Grants EAR‐0350028 and EAR‐0732947). DSMs generated in this study are available via the Open Topography portal ( https://opentopography.org/ ).
Publisher Copyright:
© 2022 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
PY - 2022/9/30
Y1 - 2022/9/30
N2 - Understanding how fault systems interact and transfer strain over seismogenic timescales (seconds to ka) requires temporal records of past ruptures along adjacent and intersecting fault networks. Here we document the record of Late Holocene ruptures as recorded in the geomorphology of alluvial deposits along the Ash Hill fault, in the Eastern California Shear Zone (ECSZ). We leverage a multi-faceted approach to evaluate the relative timing of Ash Hill fault ruptures to those of nearby faults in the ECSZ. We determine the number and timing of Late Holocene earthquakes on the Ash Hill fault using high-resolution tectono-geomorphic mapping, a locally calibrated alluvial fan stratigraphy, feldspar luminescence dating, and fault offset analysis from field observations, LiDAR, and drone-based digital surface elevation models. We find evidence for three surface-rupturing earthquakes that have occurred since ~4 ka, each with ~1.0 ± 0.2 m of oblique slip per event (Mw ~ 6.9–7.0), and we constrain the timing of these earthquakes by dating deposits that bracket each event. The timing of these three ruptures is similar to the paleoseismic record along the adjacent range-bounding fault in southern Panamint Valley. Specifically, the two adjacent faults exhibit similar numbers of earthquakes during the Late Holocene, with similar recurrence intervals and rupture timing. These data suggest that it is possible that these two faults have ruptured in the same or closely temporally related events throughout the Late Holocene. Similar spatio-temporal clustered earthquakes have been recognized in both historic and paleoseismic records in the region, and such behaviour may be common in complexly interlinked fault networks, like those that exist in the ECSZ.
AB - Understanding how fault systems interact and transfer strain over seismogenic timescales (seconds to ka) requires temporal records of past ruptures along adjacent and intersecting fault networks. Here we document the record of Late Holocene ruptures as recorded in the geomorphology of alluvial deposits along the Ash Hill fault, in the Eastern California Shear Zone (ECSZ). We leverage a multi-faceted approach to evaluate the relative timing of Ash Hill fault ruptures to those of nearby faults in the ECSZ. We determine the number and timing of Late Holocene earthquakes on the Ash Hill fault using high-resolution tectono-geomorphic mapping, a locally calibrated alluvial fan stratigraphy, feldspar luminescence dating, and fault offset analysis from field observations, LiDAR, and drone-based digital surface elevation models. We find evidence for three surface-rupturing earthquakes that have occurred since ~4 ka, each with ~1.0 ± 0.2 m of oblique slip per event (Mw ~ 6.9–7.0), and we constrain the timing of these earthquakes by dating deposits that bracket each event. The timing of these three ruptures is similar to the paleoseismic record along the adjacent range-bounding fault in southern Panamint Valley. Specifically, the two adjacent faults exhibit similar numbers of earthquakes during the Late Holocene, with similar recurrence intervals and rupture timing. These data suggest that it is possible that these two faults have ruptured in the same or closely temporally related events throughout the Late Holocene. Similar spatio-temporal clustered earthquakes have been recognized in both historic and paleoseismic records in the region, and such behaviour may be common in complexly interlinked fault networks, like those that exist in the ECSZ.
KW - Eastern California Shear Zone (ECSZ)
KW - Holocene earthquakes
KW - alluvial fan morphology
KW - drone-based structure from motion (SFM)
KW - tectonic geomorphology
UR - http://www.scopus.com/inward/record.url?scp=85133593175&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85133593175&partnerID=8YFLogxK
U2 - 10.1002/esp.5432
DO - 10.1002/esp.5432
M3 - Article
AN - SCOPUS:85133593175
SN - 0197-9337
VL - 47
SP - 2897
EP - 2925
JO - Earth Surface Processes and Landforms
JF - Earth Surface Processes and Landforms
IS - 12
ER -