Influence of pluvial lake cycles on earthquake recurrence in the northwestern Basin and Range, USA
Document Type
Book Chapter
Department or Administrative Unit
Geological Sciences
Publication Date
8-12-2021
Abstract
The Basin and Range hosted large pluvial lakes during the Pleistocene, which generally reached highstands following the Last Glacial Maximum and then regressed rapidly to near-modern levels. These lakes were large and deep enough to profoundly affect the crust through flexure; they filled basins formed by faults, and they locally modified pore pressure and groundwater conditions. A compilation of geochronologic constraints on paleoshorelines and paleoseismicity suggests temporal correlations between lake level and earthquake recurrence, with changes in earthquake rates as lakes regressed. In the northwestern Basin and Range, climatic and tectonic conditions differ from the rest of the province: The modern and glacial climate is/was cooler and wetter, glacial lakes were proportionally larger, and the crustal strain rate is lower. Numerous valleys host late Pleistocene and Holocene fault scarps and evidence of >M (sub w) 7 earthquakes in the last 15,000 yr. We compiled detailed lake hydrographs, timing of earthquakes and slip on faults, and other climatic and crustal data from Surprise Valley, Summer Lake, and the Fort Rock basin, along with additional data from other basins in the northwestern Basin and Range. We also present new mapping and topographic analysis of fault scarps that provides relative age constraints on the timing of slip events. Our results confirm temporal correlations, but the limited length of the paleoseismic record prevents definitive causation on the scale of the individual fault or lake basin. Taken together, however, data from all basins suggest that the faults in the northwestern Basin and Range could be acting as a system, with pluvial lake cycles affecting elastic strain accumulation and release across the region.
Recommended Citation
Egger, A. E., Ibarra, D. E., Weldon, R., Langridge, R. M., Marion, B., & Hall, J. (2021). Influence of pluvial lake cycles on earthquake recurrence in the northwestern Basin and Range, USA. In S. W. Starratt and M. R. Rosen (Eds.), From Saline to Freshwater: The Diversity of Western Lakes in Space and Time (pp. 97–124). Boulder, CO, Geological Society of America. https://doi.org/10.1130/2018.2536(07)
Journal
From Saline to Freshwater: The Diversity of Western Lakes in Space and Time
Rights
© 2018 The Geological Society of America. All rights reserved.
Comments
This book chapter was originally published in From saline to freshwater: The diversity of western lakes in space and time. The full-text article from the publisher can be found here.
Due to copyright restrictions, this article is not available for free download from ScholarWorks @ CWU.