HR: 14:40h
AN: H13M-04    [Abstracts]
TI: Near-Surface Site Characterization Using a Combination of Active and Passive Seismic Arrays
AU: * Lane, J W
EM: jwlane@usgs.gov
AF: US Geological Survey, OGW Branch of Geophysics 11 Sherman Place, Unit 5015, Storrs, CT 06269, United States
AU: Liu, L
EM: lanbo.liu@uconn.edu
AF: University of Connecticut, Deptartment of Civil and Environmental Engineering, Stortrs, CT 06269, United States
AU: Chen, Y
EM: yoc03001@engr.uconn.edu
AF: University of Connecticut, Deptartment of Civil and Environmental Engineering, Stortrs, CT 06269, United States
AU: White, E A
EM: eawhite@usgs.gov
AF: US Geological Survey, OGW Branch of Geophysics 11 Sherman Place, Unit 5015, Storrs, CT 06269, United States
AB: Seismic surveys with an active source are commonly used to characterize the subsurface. Increasingly, passive seismic surveys utilizing ambient seismic frequencies (microtremors) are being used to support geotechnical and hazards engineering studies. In this study, we use a combination of active and passive seismic methods to characterize a watershed site at Haddam Meadows State Park, Haddam, Connecticut. At Haddam Meadows, we employed a number of seismic arrays using both active and passive approaches to estimate the depth to rock and the seismic velocity structure of the unconsolidated sediments. The active seismic surveys included seismic refraction and multi-channel analysis of surface waves (MASW) using an accelerated weight-drop seismic source. The passive seismic surveys consisted of MASW techniques using both linear and circular geophone arrays, and a survey using a 3-component seismometer. The active seismic data were processed using conventional algorithms; the passive seismic data were processed using both the spatial autocorrelation method (SPAC) and the horizontal to vertical spectral ratio (H/V) method. The interpretations of subsurface structure from the active and passive surveys are generally in good agreement and compare favorably with ground truth information provided by adjacent boreholes. Our results suggest that a combination of active and passive seismic methods can be used to rapidly characterize the subsurface at the watershed scale.
DE: 1829 Groundwater hydrology
DE: 1835 Hydrogeophysics
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1847 Modeling
DE: 1879 Watershed
SC: Hydrology [H]
MN: 2007 Fall Meeting