Site-specific probabilistic seismic hazard analyses for the Idaho National Engineering Laboratory. Volume 2: Appendices

The identification of seismic sources is often based on a combination of geologic and tectonic considerations and patterns of observed seismicity; hence, a historical earthquake catalogue is important. A historical catalogue of earthquakes of approximate magnitude (M) 2.5 and greater for the time period 1850 through 1992 was compiled for the INEL region. The primary data source used was the Decade of North American Geology (DNAG) catalogue for the time period from about 1800 through 1985 (Engdahl and Rinehart, 1988). A large number of felt earthquakes, especially prior to the 1970`s, which were below the threshold of completeness established in the DNAG catalogue (Engdahl and Rinehart, 1991), were taken from the state catalogues compiled by Stover and colleagues at the National Earthquake Information Center (NEIC) and combined with the DNAG catalogue for the INEL region. The state catalogues were those of Idaho, Montana, Nevada, Utah, and Wyoming. NEIC`s Preliminary Determination of Epicenters (PDE) and the state catalogues compiled by the Oregon Department of Geology and Mineral Industries (DOGAMI), and the University of Nevada at Reno (UNR) were also used to supplement the pre-1986 time period. A few events reanalyzed by Jim Zollweg (Boise State University, written communication, 1994) were also modified in the catalogue. In the case of duplicate events, the DNAG entry was preferred over the Stover et al. entry for the period 1850 through 1985. A few events from Berg and Baker (1963) were also added to the catalogue. This information was and will be used in determining the seismic risk of buildings and facilities located at the Idaho National Engineering Laboratory