Seismo-lineament analysis of selected earthquakes in the Tahoe-Truckee area, California and Nevada.

Abstract

Focal mechanism solutions from 29 M≥3 earthquakes recorded between 1966 and late 2009 in the Tahoe-Truckee area, California and Nevada, were used to establish a preliminary spatial correlation between these earthquakes and faults. In previous studies, only the 1966 Truckee earthquake (M 6) had been correlated with a fault: the Dog Valley fault. The most recent events on other Quaternary faults in the area were previously attributed to the mid-Holocene to Pleistocene. In this study, preliminary spatial correlation has been described between one or more earthquakes and the Dog Valley fault zone, Polaris fault, West Tahoe fault, North Tahoe fault, Incline Village fault and the hypothetical Agate Bay fault. Two additional trends are defined by seismo-lineaments and geomorphic indicators of possible faulting, and might encompass previously unrecognized seismogenic faults. This area is subject to earthquakes on north-striking east-dipping normal faults, northwest-striking dextral faults and their conjugates -- northeast-striking sinistral faults.