Abstract
We use noise correlation and surface wave inversion to measure the S wave velocity changes at different depths near Parkfield, California, after the 2003 San Simeon and 2004 Parkfield earthquakes. We process continuous seismic recordings from 13 stations to obtain the noise cross-correlation functions and measure the Rayleigh wave phase velocity changes over six frequency bands. We then invert the Rayleigh wave phase velocity changes using a series of sensitivity kernels to obtain the S wave velocity changes at different depths. Our results indicate that the S wave velocity decreases caused by the San Simeon earthquake are relatively small (similar to 0.02%) and access depths of at least 2.3 km. The S wave velocity decreases caused by the Parkfield earthquake are larger (similar to 0.2%), and access depths of at least 1.2 km. Our observations can be best explained by material damage and healing resulting mainly from the dynamic stress perturbations of the two large earthquakes.
Item Type: | Journal article |
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Faculties: | Geosciences > Department of Earth and Environmental Sciences |
Subjects: | 500 Science > 550 Earth sciences and geology |
ISSN: | 0094-8276 |
Language: | English |
Item ID: | 48860 |
Date Deposited: | 27. Apr 2018, 08:16 |
Last Modified: | 04. Nov 2020, 13:26 |