Adjoint Tomography of the Southern California Crust
- Creators
-
Tape, Carl
- Liu, Qinya
- Maggi, Alessia
-
Tromp, Jeroen
Abstract
Using an inversion strategy based on adjoint methods, we developed a three-dimensional seismological model of the southern California crust. The resulting model involved 16 tomographic iterations, which required 6800 wavefield simulations and a total of 0.8 million central processing unit hours. The new crustal model reveals strong heterogeneity, including local changes of ±30% with respect to the initial three-dimensional model provided by the Southern California Earthquake Center. The model illuminates shallow features such as sedimentary basins and compositional contrasts across faults. It also reveals crustal features at depth that aid in the tectonic reconstruction of southern California, such as subduction-captured oceanic crustal fragments. The new model enables more realistic and accurate assessments of seismic hazard.
Additional Information
© 2009 American Association for the Advancement of Science. Received for publication 22 April 2009. Accepted for publication 29 June 2009. Seismic waveforms were provided by the Southern California Earthquake Data Center (SCEDC), the Northern California Earthquake Data Center (NCEDC), the Incorporated Research Institutions for Seismology (IRIS), and the University of Nevada Reno. All earthquake simulations were performed on the CITerra Dell cluster at the Division of Geological and Planetary Sciences of the California Institute of Technology. M. Sambridge suggested using a source subspace projection method to compute the tomographic model update. We acknowledge support by the National Science Foundation under grant EAR-0711177. This research was supported by the Southern California Earthquake Center. SCEC is funded by NSF Cooperative Agreement EAR-0106924 and U.S. Geological Service Cooperative Agreement 02HQAG0008. The SCEC contribution number for this paper is 1261. The Fortran90 software packages SPECFEM3D and FLEXWIN are available for download at www.geodynamics.org. Supporting Online Material: www.sciencemag.org/cgi/content/full/325/5943/988/DC1 SOM Text; Figs. S1 to S9; Tables S1 to S5; ReferencesAdditional details
- Eprint ID
- 15622
- Resolver ID
- CaltechAUTHORS:20090904-130214637
- EAR-0711177
- NSF
- Southern California Earthquake Center
- EAR-0106924
- NSF
- 02HQAG0008
- USGS
- Created
-
2009-09-22Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Other Numbering System Name
- Southern California Earthquake Center contribution
- Other Numbering System Identifier
- 1261