SH-wave Reflection Imaging in Unlithified Sediment-an Environmental and Seismic Hazards Application
The SH-wave seismic reflection technique is a viable tool for shallow engineering and environmental imaging in unlithified sediment,because of its insensitivity to ground-water masking,as well as frequent ability to provide higher resolution relative to the traditional P-wave method.We acquired 26.4 km of near-surface SH-wave seismic reflection data at a central United States energy enrichment facility to image possible neotectonic structure in the thick post-Paleozoic unlithified sediment (~100 m) that overlies the southwestern projection of a late-Precambrian–early Paleozoic fault complex.The site lies in an area of diffuse seismicity near the New Madrid seismic zone,as well as exhibits an anomalously migrating ground-water contaminant plume.Results show that the fault complex has been reactivated and deformation extends above the carbonate bedrock into the thick low-velocity Cretaceous,Tertiary,and Quaternary sediment.Reflection images along with correlative drilling and dating methods indicate no perceptible deformation later than 16.6 ka,however.Data also show two northeast striking high-angle bedrock fault strands,extending into the lower part of a Pleistocene-Pliocene sand and gravel aquifer,bound and are coincident with the highest concentrations of the contaminant plume,suggesting a structurally controlled preferential groundwater flow path.
seismic reflection SH-waves seismic hazards hydrogeophysics
Edward W.Woolery Ali Almayahi Steve Hampson Cora Blits Zhenming Wang
Dept. of Earth and Environmental Sciences, University of Kentucky, KY, USA 40506 Kentucky Research Consortium for Energy and Environment, University of Kentucky, KY, USA 40506 Kentucky Geological Survey, University of Kentucky, KY, USA 40506
国际会议
长沙
英文
287-293
2012-06-15（万方平台首次上网日期，不代表论文的发表时间）