Virtual California visualized with RIVA, all California Case

This is an example of a 1000-year simulation produced by the computer code "Virtual California" visually rendered by the RIVA software. The map is a LandSat image of California, and the black lines represent the major strike-slip earthquake faults. In the model, the faults are divided into 650 segments, each approximately 10 km long, and exactly 15 km deep. After the movie is started, the viewer will see a series of butterfly" images of various sizes centered on the faults. The butterflies represent the displacement of the ground surface as they would be reconstructed from observations taken by an interferometric radar satellite having a radar wavelength of 5.7 cm. The sizes of the butterflies are related to the sizes of the earthquakes they represent. The color contours can be interpreted as a kind of contour map of the change in ground displacement due to an earthquake, with each color cycle (i.e., red-blue-red) representing 5.7 cm of displacement along the line of sight to the spacecraft. The displacement changes are computed over a time interval of 5 years, and each movie frame represents an advance of 1 year in the ground displacement. The viewer can easily see that an important characteristic of the earthquakes in the simulation is the clustering of the earthquake butterflies in space and time. Clustering of this type is also seen in real earthquakes, and the simulations tell us that it is due to the elastic interactions between fault segments, combined with the nonlinear nature of the friction law governing slip on each fault segment.

Category:

Science & Technology

Tags:

• virtual
• california
• vc
• earthquake