Our survey consists of two seismic profiles, a 3-km-long E-W profile and a 5-km-long N-S profile. The N-S profile included both Betsy Seisgun and buried explosives and was recorded with a series of linked multi-channel (Geometrics) seismographs attached via multi-channel cables to 40-Hz, single-element vertical and horizontal geophones spaced at 5-m intervals. and RefTek 125A -Texan seismographs. The E-W profile just include Besty Seisgun sources and Geometrics recording.