Other
Scientific paper
Sep 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005geoji.162.1036e&link_type=abstract
Geophysical Journal International, Volume 162, Issue 3, pp. 1036-1048.
Other
2
Scientific paper
High quality observations of shear-wave anisotropy in the shallow crust have allowed us to detect subsurface crack systems in the NW and the SE Geysers geothermal fields, CA. Shear-wave splitting (SWS) parameters, fast shear-wave polarizations (φ) and time delays (δt), are highly sensitive to the anisotropic fabric of the medium through which shear-waves propagate and constitute the basic dataset to invert for 3-D crack geometry and crack density in the subsurface. Variation and asymmetry patterns in φ and δt observations, plotted in equal-area projections as a function of ray azimuth and incident angle, are essential in the determination of crack strike and dip, crack aspect ratio, and crack density. Inversion results show that the most common patterns of fracture-induced anisotropy in the NW Geysers can be simulated by horizontally transversely isotropic (HTI) media or rocks with vertical (to steeply-dipping) systems of parallel cracks which strike subparallel to the N-to-NE direction of maximum compressive stress. On the other hand, modelled fracture systems in the SE Geysers strike both NE and NW. Percentages of shear-wave velocity anisotropy average about 4 per cent in The Geysers. Deviations from horizontal transverse isotropy conditions are modelled with non-vertically dipping crack systems or with intersecting crack systems. The discussion of specific inversion examples exposes problems related to seismic ray coverage within the shear-wave window, non-uniqueness of crack-induced anisotropy models, and complementarity between polarization and time delay data.
Elkibbi Maya
Rial José A.
Yang Ming
No associations
LandOfFree
Crack-induced anisotropy models in The Geysers geothermal field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Crack-induced anisotropy models in The Geysers geothermal field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Crack-induced anisotropy models in The Geysers geothermal field will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1286699