Regional three-dimensional seismic velocity model of the crust and uppermost mantle of northern California
We present a three-dimensional (3D) tomographic model of the P wave velocity (Vp) structure of northern California. We employed a regional-scale double-difference tomography algorithm that incorporates a finite-difference travel time calculator and spatial smoothing constraints. Arrival times from earthquakes and travel times from controlled-source explosions, recorded at network and/or temporary stations, were inverted for Vp on a 3D grid with horizontal node spacing of 10 to 20 km and vertical node spacing of 3 to 8 km. Our model provides an unprecedented, comprehensive view of the regional-scale structure of northern California, putting many previously identified features into a broader regional context and improving the resolution of a number of them and revealing a number of new features, especially in the middle and lower crust, that have never before been reported. Examples of the former include the complex subducting Gorda slab, a steep, deeply penetrating fault beneath the Sacramento River Delta, crustal low-velocity zones beneath Geysers-Clear Lake and Long Valley, and the high-velocity ophiolite body underlying the Great Valley. Examples of the latter include mid-crustal low-velocity zones beneath Mount Shasta and north of Lake Tahoe. Copyright 2009 by the American Geophysical Union.
Citation Information
Publication Year | 2009 |
---|---|
Title | Regional three-dimensional seismic velocity model of the crust and uppermost mantle of northern California |
DOI | 10.1029/2008JB005766 |
Authors | C. Thurber, H. Zhang, T. Brocher, V. Langenheim |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of Geophysical Research B: Solid Earth |
Index ID | 70035804 |
Record Source | USGS Publications Warehouse |