Fault Activity and Seismicity near the Los Alamos los alamos Scientific Laboratory Geothermal Test Site, Jemez Mountains, New Mexico

摘要

The purpose of this study is to develop guidelines for evaluating geothermal sites for earthquake hazards and for the possibility of siting on an active fault. These guidelines were used to minimize these risks for a specific geothermal test site of the Los Alamos los alamos Scientific Laboratory (LASL) on the Jemez Plateau, a few miles west of the Valles Caldera, at the center of the Jemez Mountains in north-central New Mexico.nThe approach to the problem involves new methods of low-sun-angle aerial photography and photogeology, in combination with conventional geo-logical and seismicity studies. The possibility of future surface faulting or occurrence of strong local earthquakes is analyzed by comparing the structural and seismic setting of the area of investigation with that of the Rio Grande depression and other active zones in the western United States. The evaluation includes identification, delineation and character¬ization of faults in the region with conventional high-sun-angle aerial photographs, special low-sun-angle aerial photographs taken specifically for this project, Earth Resources Technology Satellite (ERTS) imagery, manned space satellite photography, search of the geological literature, and aerial and ground reconnaissance using both low and high sun angles of illumination at midday, early morning, and late afternoon.nThe site area is near the western edge of the Rio Grande depression, the most active seismic zone of New Mexico. The Rio Grande depression is marked in places by geologically youthful fault scarps and in places is known to have significant normal faults.