Second Quarter Hanford Seismic Report for Fiscal Year 2008

Rohay, Alan C. ; Sweeney, Mark D. ; Hartshorn, Donald C. ; Clayton, Ray E. ; Devary, Joseph L.

Pacific Northwest National Laboratory (U.S.)

关键词: Seismic Surveys;    58 Geosciences;    Depth;    Earthquakes;    Seismic Sources;   

DOI  :  10.2172/961685
RP-ID  :  PNNL-17654
RP-ID  :  AC05-76RL01830
RP-ID  :  961685

美国|英语

来源: UNT Digital Library

【 摘 要 】

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 Hanford Seismic Assessment Team locates and identifies sources of seismic activity and monitors 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 seismic monitoring organization 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. For the Hanford Seismic Network, seven local earthquakes were recorded during the second quarter of fiscal year 2008. The largest event recorded by the network during the second quarter (February 3, 2008 - magnitude 2.3 Mc) was located northeast of Richland in Franklin County at a depth of 22.5 km. With regard to the depth distribution, two earthquakes occurred at shallow depths (less than 4 km, most likely in the Columbia River basalts), three earthquakes at intermediate depths (between 4 and 9 km, most likely in the pre-basalt sediments), and two earthquakes were located at depths greater than 9 km, within the crystalline basement. Geographically, five earthquakes occurred in swarm areas and two earthquakes were classified as random events.