Constraining earthquake source inversions with GPS data: 2. A two-step approach to combine seismic and geodetic data sets
Journal of Geophysical Research B: Solid Earth
By: S. Custodio, M.T. Page, and R.J. Archuleta
Links
- More information: Publisher Index Page (via DOI)
- Open Access Version: Publisher Index Page
- Download citation as: RIS | Dublin Core
Abstract
We present a new method to combine static and wavefield data to image earthquake ruptures. Our combined inversion is a two-step procedure, following the work of Hernandez et al. (1999), and takes into account the differences between the resolutions of the two data sets. The first step consists of an inversion of the static field, which yields a map of slip amplitude. This inversion exploits a special irregular grid that takes into account the resolution of the static data. The second step is an inversion of the radiated wavefield; it results in the determination of the time evolution of slip on the fault. In the second step, the slip amplitude is constrained to resemble the static slip amplitude map inferred from the GPS inversion. Using this combined inversion, we study the source process of the 2004 M6 Parkfield, California, earthquake. We conclude that slip occurred in two main regions of the fault, each of which displayed distinct rupture behaviors. Slip initiated at the hypocenter with a very strong bilateral burst of energy. Here, slip was localized in a narrow area approximately 10 km long, the rupture velocity was very fast (???3.5 km/s), and slip only lasted a short period of time (<1 s). Then the rupture proceeded to a wider region 12-20 km northwest of the hypocenter. Here, the earthquake developed in a more moderated way: the rupture velocity slowed to ???3.0 km/s and slip lasted longer (1-2 s). The maximum slip amplitude was 0.45 m. Copyright 2009 by the American Geophysical Union.
Suggested Citation
Custodio, S., Page, M., Archuleta, R., 2009, Constraining earthquake source inversions with GPS data: 2. A two-step approach to combine seismic and geodetic data sets: Journal of Geophysical Research B: Solid Earth, v. 114, no. 1, https://doi.org/10.1029/2008JB005746.
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Constraining earthquake source inversions with GPS data: 2. A two-step approach to combine seismic and geodetic data sets |
| Series title | Journal of Geophysical Research B: Solid Earth |
| DOI | 10.1029/2008JB005746 |
| Volume | 114 |
| Issue | 1 |
| Publication Date | January 27, 2009 |
| Year Published | 2009 |
| Language | English |
| Larger Work Type | Article |
| Larger Work Subtype | Journal Article |
| Larger Work Title | Journal of Geophysical Research B: Solid Earth |