Shear wave anisotropy observed in VSP data at the San Andreas fault observatory at depth

Abstract

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2005Shear wave anisotropy observed in VSP data at the San Andreas fault observatory at depthAuthors: Stewart TaylorPeter MalinJakob B. U. HaldorsenStewart TaylorDuke UniversitySearch for more papers by this author, Peter MalinDuke UniversitySearch for more papers by this author, and Jakob B. U. HaldorsenSchlumberger‐Doll ResearchSearch for more papers by this authorhttps://doi.org/10.1190/1.2144291 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract The San Andreas Fault (SAF) is the surface expression of a major plate tectonic boundary of the Pacific Plate. While widely known as the San Andreas Fault, it is probably better thought of as an extensive fault system that represents a major transform boundary between the North American and Pacific Plates. The sequence of M=6 earthquakes along the fault near Parkfield, California has stimulated an intense research effort into the seismogenic processes of brittle deformation in the upper crust along the San Andreas Fault. Part of this research effort has led to large network of surface instrumentation in the vicinity of Parkfield including seismometers, strain meters, and a variety of other geologic monitoring equipment. Recently, further instrumentation efforts have focused primarily on subsurface monitoring of seismogenic processes as part of the San Andreas Fault Observatory at Depth (SAFOD) project. In this paper, we review our recent research conducted to determine the local subsurface structure at the SAFOD site. We then present our structural interpretation of vertical seismic profiling data collected during recent crustal profiling studies. We conclude that the observed shear wave anisotropy in our VSP data is the result of aligned fracture sets which are most likely R shears. R shears are one component of conjugate Riedel fracturing associated with shear zone tectonic deformation.Permalink: https://doi.org/10.1190/1.2144291FiguresReferencesRelatedDetailsCited byFault delineation using earthquake energy as a source for pre-stack depth imagingJakob B. U. Haldorsen, Stewart Taylor*, and Douglas E. Miller5 August 2014Vs, Vp, and trends of elastic constants for active faultsStewart Thomas Taylor14 October 2009Interferometric deconvolution of VSP dataStewart Taylor, Douglas E. Miller, Jakob B. U. Haldorsen, and Richard Coates14 September 2007 SEG Technical Program Expanded Abstracts 2005ISSN (print):1052-3812 ISSN (online):1949-4645Copyright: 2005 Pages: 2668 publication data© 2005 Copyright © 2005 Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished Online: 07 Dec 2005 CITATION INFORMATION Stewart Taylor, Peter Malin, and Jakob B. U. Haldorsen, (2005), "Shear wave anisotropy observed in VSP data at the San Andreas fault observatory at depth," SEG Technical Program Expanded Abstracts : 174-177. https://doi.org/10.1190/1.2144291 Plain-Language Summary PDF DownloadLoading ...