Spatiotemporal Clustering of Paleoseismicity in the Walker Lane, USA: An Extensional Supercycle?

Abstract

At least five surface rupturing earthquakes that occurred during a <300 year time span near Carson City, Nevada, USA form a spatiotemporal cluster of earthquakes similar to those observed on fault systems around the world. These earthquakes exhibit not only temporal clustering behavior, but also have varying rupture boundaries during successive earthquakes. The Carson Range Fault System is a series of east-dipping normal faults that extend ∼100 km southwards from Reno, Nevada. Previously published paleoseismic and lidar data spanning this system provide evidence of five surface rupturing earthquakes that occurred across the Carson Range Fault System during the last 2,500 years. The three most recent of these earthquakes occurred from 800 to 500 cal ybp, and two other earthquakes occurred on the nearby Incline Village and East Carson Valley faults during this time. Together these five Mw6.4–7.3 earthquakes form a spatiotemporal cluster or supercycle.