HR: 0800h
AN: U21B-0815    [Abstracts]
TI: 3-D Autojuggie: Automating Deployment of Two-Dimensional Geophone Arrays for Efficient Ultra-Shallow Seismic-Reflection Surveys
AU: * Tsoflias, G P
EM: tsoflias@ku.edu
AF: The University of Kansas, 1475 Jayhawk Blvd., 120 Lindley Hall, Lawrence, KS 66045 United States
AU: Steeples, D W
EM: don@ku.edu
AF: The University of Kansas, 1475 Jayhawk Blvd., 120 Lindley Hall, Lawrence, KS 66045 United States
AU: Czarnecki, G
EM: gpczarne@ku.edu
AF: The University of Kansas, 1475 Jayhawk Blvd., 120 Lindley Hall, Lawrence, KS 66045 United States
AU: Sloan, S D
EM: sloansd@ku.edu
AF: The University of Kansas, 1475 Jayhawk Blvd., 120 Lindley Hall, Lawrence, KS 66045 United States
AU: Eslick, R
EM: rocyes@yahoo.com
AF: The University of Kansas, 1475 Jayhawk Blvd., 120 Lindley Hall, Lawrence, KS 66045 United States
AB: Near-surface seismic reflection methods require dense spatial sampling of the wavefield. Seismic surveys imaging the top ten meters of the subsurface employ geophone spacing on the order of decimeters. Two-dimensional (2-D), ultra-shallow seismic reflection methods have increased in popularity. However, placement of geophones remains a labor-intensive deterrent to the acquisition of near-surface, 3-D seismic data. Although 3-D seismic imaging is a mature hydrocarbon-exploration technique, only a handful of 3-D shallow seismic surveys have been acquired over the last decade. We present the development and field-testing of instrumentation for automatic deployment of a 2-D array of 72 geophones for acquisition of ultra-shallow 3-D reflection seismic data, referred to as the 3-D Autojuggie. The main components of the instrumentation include: a) two vertically stacked rigid steel frames used for positioning, planting, and transporting an array of geophones; b) an hydraulically controlled mechanism for decoupling the geophones from the steel frames during seismic data recording; and c) a 2-D array of seventy-two 100 Hz Mark Products geophones with 20.32 cm long spikes, spaced 20 cm apart in the inline (12 geophones) and crossline (6 rows) orientation. Seismic noise testing (walkaways) conducted at The University of Kansas employing automatically planted 2-D geophone arrays next to conventional hand-planted geophones resulted in equivalent seismic imaging of the subsurface. The geophone planting instrumentation did not degrade the quality of the recorded wavefield. The efficiency of automatically placing a dense 2-D array of geophones on the ground and the ease of moving the array quickly to adjacent positions, along with the ability to acquire comparable quality data to conventional hand-planted geophones, indicate that the 3-D Autojuggie is a viable approach to ultra-shallow 3-D seismic acquisition. Conceptually, the design could accommodate an array of hundreds of geophones at once.
DE: 0935 Seismic methods (3025, 7294)
DE: 0994 Instruments and techniques
DE: 0999 General or miscellaneous
DE: 1835 Hydrogeophysics
SC: Union [U]
MN: Fall Meeting 2005