Yucca Mountain Seismic Monitoring
Yucca Mountain, in southern Nevada, is under study as a potential permanent underground repository for high-level nuclear waste. The Seismological Laboratory has responsibility, under a cooperative agreement grant from the Department of Energy, to monitor the seismicity in the area surrounding Yucca Mountain, Nevada, as part of the site characterization program. We operate several types of instruments to perform this monitoring. All earthquakes are recorded on a network of digital, three-component seismic stations called the Southern Great Basin Digital Seismic Network (SGBDSN). The network covers an area of approximately 50-km radius around Yucca Mountain (PDF). The data is digitized onsite with 24-bit recorders and transmitted in near-real-time to the Nevada Seismological Laboratory. Each recorder can be programmed remotely from the lab using the full duplex telemetry capability. Continuous (20 sps) and triggered (100 sps) data are archived at the lab from all incoming channels.
Due to low seismic background noise and to the high density of stations, the SGBDSN has a very low threshold for earthquake detection, routinely seeing earthquakes of magnitudes near zero and below, as shown by the recurrence curve of earthquakes located there. During the first five years of operation, approximately 12,000 earthquakes have been located within and near the fringe of the network. You can view a earthquake map for year 2000 in the vicinity of Yucca Mountain, an earthquake map for years 1978-2000 in the southern Great Basin, or a map of earthquakes recorded by the NSL from when we took over monitoring in 1992 until 2006 (PDF). Additionally, numerous regional and teleseismic events are recorded daily. For a broad perspective on earthquakes in California and Nevada, view the CA-NV seismicity map.
In addition to the permanent network of monitoring stations, a strong-motion network of accelerometers has also been installed. A first set of 9 strong-motion sites were installed in 1996; they are independent sites requiring site visits to retrieve data. A second set of 10 were installed in 2000 at regular monitoring sites and were connected to the field recorders, thus enabling real-time data collection via the telemetry link. Earthquakes within 50 km of Yucca Mountain and having at least M 3.5 should trigger the majority of these strong-motion sites.
Data from this network is contributing to the following seismic studies:
- spatial and temporal seismicity patterns
- focal mechanisms of earthquakes
- earthquake source physics
- travel-time tomography
- rock properties characterization
- attenuation of seismic waves
- seismic hazard assessment
Quarterly Reports Submitted to the Harry Reid Center on this Project Last updated 08/18/2006
