Earthquake Hazard in the Reno-Tahoe-Carson City Area

Dana Marino, Christie D. Rowe, Rich D. Koehler, Kyren R. Bogolub, Hannah Martin, Daniel T. Trugman, John N. Louie, Patricia H. Cashman, Elnaz Seylabi, & Steven G. Wesnousky

Submitted September 7, 2025, SCEC Contribution #14684, 2025 SCEC Annual Meeting Poster #TBD

The Reno-Carson-Tahoe region of Nevada is one of the fastest growing urban areas in the US and lies within the Walker Lane tectonic zone. The Reno-Sparks metro area lies in a triangular valley containing a network of N-striking normal faults, NW-striking right-lateral faults and NE-striking left-lateral faults. Potentially damaging earthquakes of M4.5 or greater were frequent in the late 19th and early 20th centuries, with at least 20 events between the 1850s and 1960s. A period of relative quiescence after the large earthquakes in central Nevada in the 1950s ended with more observed activity from the 1990s to present, including several swarms culminating in felt events and minor damage. Reno-Sparks-Carson-Tahoe now has a population exceeding half a million, and is considered to be an area of high hazard and risk given the tectonic setting and record of historical and recent earthquakes.

High resolution lidar DEMs have been available for about a decade, allowing for detailed mapping of some Quaternary active faults. Relocated seismicity catalogs exist for post-2008 sequences, and moment tensor solutions have been compiled for recent M3+ events. Active fault traces with geomorphic expression are well-mapped. Local studies have helped constrain fault dip direction, fault linkages, and in some cases, total displacement, slip rate and recurrence. A few potential earthquake scenarios for use in planning have been developed, along with a community velocity model for scenario-shaking computation.

However, a comprehensive reassessment of the Reno basin and surrounding region has not been completed. Commonly used fault map sources (e.g. the USGS Quaternary Faults and Folds database, NSHM2023) are in need of updates and curation using higher resolution datasets. The 3D orientation and length of some major faults and fault systems are insufficiently constrained, and given long recurrence intervals on some Walker Lane faults, it remains ambiguous whether the faults with geomorphic surface expression should be considered the most hazardous or whether buried faults still pose modern threats, such as those responsible for recent urban earthquake swarms.

We present the state of knowledge for the Reno-Sparks-Carson-Tahoe area, synthesizing geologic mapping, geophysical investigations, seismicity patterns, available geochronology, and motivate priorities for future earthquake hazard research.

Citation
Marino, D., Rowe, C. D., Koehler, R. D., Bogolub, K. R., Martin, H., Trugman, D. T., Louie, J. N., Cashman, P. H., Seylabi, E., & Wesnousky, S. G. (2025, 09). Earthquake Hazard in the Reno-Tahoe-Carson City Area. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Geology