publications by Peter E. Malin.
- Taylor, Stewart T. and Stolte, Christian and Haldorsen, Jakob B.U. and Coates, Richard and Malin, Peter and Shalev, Eylon, Drillbit seismic images fractures of San Andreas fault system,
Oil and Gas Journal, vol. 103 no. 41
pp. 42 - 44 .
(last updated on 2007/04/09)
Scientists recently used the drillbit seismic technique to image fractures and shear zones associated with the San Andreas fault near Parkfield, Calif. Low-level energy produced by the drillbit served as a downhole seismic source, and the wave response was measured by an array of geophones at the surface. In the complex structural environment underlying Parkfield, numerous faults that comprise a flower structure are interpreted to cut the Cenozoic sedimentary cover and the Salinian block at the San Andreas Fault Observatory at Depth (SAFOD) project drillsite. Based on updated surface geologic maps by Rymer, these fractures and faults appear to trend subparallel to the San Andreas fault (SAF) and have been mapped up to 3 km to the southwest of the main trace of the SAF. Our study included the interpretation of a surface seismic profile and the drillbit seismic data. These data indicate that faulting is more abundant and shearing more pervasive as one approaches the main trace of the San Andreas fault. In addition, our interpretation of the locations and dips of faults in the PSINE profile correlates very well with locations and dips of several linear features imaged in the migrated drillbit seismic data.
Seismology;Tectonics;Fracture;Seismic waves;Structural geology;Sedimentary rocks;