Popis: |
The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the event of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. The Hanford Seismic Network recorded 16 local earthquakes during the first quarter of FY 2011. Six earthquakes were located at shallow depths (less than 4 km), seven earthquakes at intermediate depths (between 4 and 9 km), most likely in the pre-basalt sediments, and three earthquakes were located at depths greater than 9 km, within the basement. Geographically, thirteen earthquakes were located in known swarm areas and three earthquakes were classified as random events. The highest magnitude event (1.8 Mc) was recorded on October 19, 2010 at depth 17.5 km with epicenter located near the Yakima River between the Rattlesnake Mountain and Horse Heaven Hills swarm areas. |