Ground Motion Evaluation for Jackson Lake Dam
Final Report

Overview

This report provides a detailed characterization of the ground motions that might affect Jackson Lake Dam due to a large earthquake on the Teton fault.

The Teton fault is an active normal fault capable of producing M 7+ earthquakes. The surface trace of the fault is located 12 km (7 mi) west of Jackson Lake Dam. The fault plane dips to the east, likelyextending to a position below the dam.

This report is based on regional seismic monitoring data, empirical site response measurements, results of previous geologic investigations, and ground motion modelling.

This report examines ground motions from the Teton fault only. While there are other sources of earthquakes in the region, previous probabilistic seismic hazard analyses by Reclamation indicate that the Teton fault is the controlling seismic source based on proximity, activity rates, and maximum earthquake magnitudes. At some locations on the dam which are more susceptible to liquefaction, ground motions from additional sources may be significant. The emphasis in the current ground motion analyses is therefore to characterize potential Teton fault earthquakes, and to investigate the effects of geologic structure on seismic wave propagation and site response.

This report provides design ground motions that are intended to be used as input for engineering analyses of the dam.

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For a copy of the Report CD, contact Dean Ostenaa.

Last Update: February 20, 2007 4:16 PM