Detecting high-contrast seismic anomalies using cross-borehole probing. [Measurements at different depths between boreholes]

Journal Article · Thu Mar 01 04:00:00 EST 1984 · IEEE Trans. Geosci. Remote Sens.; (United States)

DOI:https://doi.org/10.1109/TGRS.1984.350599· OSTI ID:6747606

Lyttle, R J; Portnoff, M R

Seismic probing between boreholes is useful for locating high-contrast geophysical anomalies such as an abandoned tunnel. Theoretical studies of continuous wave (CW) seismic wave interaction with a tunnel show that both the signal minima and the phase structure of the received signal can be used for locating the anomaly. The theoretical studies show that as the source and receiver are lowered in separate boreholes straddling the anomaly, the signal minima and the phase structure can be interpreted to yield both the lateral and vertical positions of the anomaly. Plane waves of compressional, horizontally polarized shear, and vertically polarized shear wave types incident on a cylindrical horizontal anomaly have been considered. The total seismic field has been calculated using an exact formulation. The variation of the response is studied as a function of the ratio of anomaly diameter to wavelength. The resulting fields in the receiver borehole are an effective diagnostic when a wavelength in the surrounding medium is less than or equal to the diameter of the anomaly. These results are analogous to the corresponding electromagnetic case which has been studied previously.

• Research Organization: Lawrence Livermore Nat'l. Lab., Livermore, CA 94550
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6747606
• Journal Information: IEEE Trans. Geosci. Remote Sens.; (United States), Journal Name: IEEE Trans. Geosci. Remote Sens.; (United States) Vol. 22:2; ISSN IGRSD
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580203* -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
BOREHOLES
CALCULATION METHODS
CAVITIES
DIMENSIONS
ELECTROMAGNETISM
GEOPHYSICAL SURVEYS
MAGNETISM
PHASE STUDIES
SEISMIC SURVEYS
SEISMIC WAVES
SHEAR
SIGNALS
SURVEYS
TUNNELS
UNDERGROUND FACILITIES
WAVELENGTHS