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- Title: SAN ANDREAS FAULT STRESSES
-
- Description:
-
- The seventeen images comprising this dataset represent the
- calculated horizontal shear stress on a vertical slice across the
- San Andreas fault zone. The calculations are from a finite
- element model which simulates the accumulation and release of
- strain on a strike slip fault which cuts through an elastic /
- viscoelastic earth model. Earthquakes occur periodically in
- this model with a period of 162 years, and the time interval
- between frames is 10 years. The vertical scale is somewhat
- exaggerated in the displayed images; the vertical range of
- depths is 0 - 15 km, while the lateral width of the image is
- 200 km. The range of shear stress magnitudes displayed by the
- image palette is 0 - 130 MPa (0 - 1300 bars).
- Earthquakes occur when stress on the fault (center of image)
- exceeds 100 MPa. The earthquake relieves the stress down to a
- level of 10 Mpa, starting the next accumulation cycle. Since
- the cycle is periodic, viewing the animation repeatedly with
- NCSA Image provides visualization of the migration of stress
- on succcesive earthquake cycles.
- The 17 frames are provided in NCSA DataScope HDF format.
- These files include both floating point data (60 x 68 points)
- and HDF color image data (240 x 408 pixels). They also include
- an HDF palette which has been selected to bring out features
- of interest. This notice is included in the notebook of
- the first HDF file in the sequence ( SAF006 ).
-
- Generation:
-
- The original model data were generated using a geophysical
- finite element code called "visco" running on the Ames Research
- Center/NAS Cray Y-MP supercomputer. The simulation required
- approximately 2000 seconds of Y-MP cpu time. The HDF data sets
- given here were generated from ASCII data using NCSA DataScope
- running on a Macintosh II. NCSA Image was used to display
- the animation.
-
- Authors:
-
- Gregory A. Lyzenga
- Jet Propulsion Laboratory
- Mail Stop 238-332
- Pasadena, CA 91109
- email: gregl@hyper-sun7.jpl.nasa.gov
- phone: (818) 354-6920
-
- Arthur Raefsky
- 201 AEL
- Stanford University
- Stanford, CA 94305
- email: arthur@pudleys.stanford.edu
- phone: (415) 723-4138
-
- Reference:
-
- Kroger, P. M., G. A. Lyzenga, K. S. Wallace, and J. M. Davidson,
- Tectonic Motion in the Western United States Inferred from
- Very Long Baseline Interferometry Measurements, 1980-1986,
- J. Geophys. Res., 92, 14151-14163 (1988)
-