Date of Award
Master of Science
Charles Adams Langston
This study tests the effectiveness of the wave gradiomety array analysis technique in extracting the wave parameters from the borehole data. 80 3-component high-frequency borehole accelerometers were integrated in a tube and clamped along the wall of San Andreas Fault Observatory at Depth (SAFOD) main hole. Data were recorded from six shots of size 2.3 to 4.5 kg and several 36.3 kg pentolite explosives with the accelerometers at three different positions in the borehole. Wave gradiomety and travel time array analysis techniques were used to investigate the velocity structure around the SAFOD borehole. The results show that both techniques can be used for borehole data analysis with the observed exception that the travel time analysis exaggerates differences in P-wave velocity between adjacent layers. The P-wave velocity structure obtained from wave gradiomety and VSP have shown much similarity with some exceptions at the depth of 0.8 km and below 2.0 km. Wave gradiomety can be effectively used for borehole data analysis since the wave gradiomety results agreed well with the inferred borehole geology and well-logs.
dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Ayele, Mehari Melak, "Crustal Velocity Structure around the SAFOD Borehole using Vertical Wave Gradiometry" (2012). Electronic Theses and Dissertations. 527.