Strong SH -to-Love Wave Scattering off the Southern California Continental Borderland
Abstract
Seismic scattering is commonly observed and results from wave propagation in heterogeneous medium. Yet deterministic characterization of scatterers associated with lateral heterogeneities remains challenging. In this study, we analyze broadband waveforms recorded by the Southern California Seismic Network and observe strongly scattered Love waves following the arrival of teleseismic SH wave. These scattered Love waves travel approximately in the same (azimuthal) direction as the incident SH wave at a dominant period of ~10 s but at an apparent velocity of ~3.6 km/s as compared to the ~11 km/s for the SH wave. Back projection suggests that this strong scattering is associated with pronounced bathymetric relief in the Southern California Continental Borderland, in particular the Patton Escarpment. Finite-difference simulations using a simplified 2-D bathymetric and crustal model are able to predict the arrival times and amplitudes of major scatterers. The modeling suggests a relatively low shear wave velocity in the Continental Borderland.
Additional Information
© 2017 American Geophysical Union. Received 6 AUG 2017; Accepted 29 AUG 2017; Accepted article online 21 SEP 2017; Published online 21 OCT 2017. Broadband seismic waveform data are retrieved from the Caltech/USGS SCSN (doi:10.7914/SN/CI) stored at SCEDC (doi:10.7909/C3WD3xH1). Figure 1 is prepared with the Generic Mapping Tools (Wessel et al., 2013). We appreciate the constructive reviews from Jeffery Park and Arthur Rodgers. Comments from Tom Brocher, Yuehua Zeng, Victor Tsai, and Don Helmberger help improve the manuscript. We thank Daniel Bowden for providing the tomography model in the Continental Borderland. Z. Z. and C. Y. were funded by USGS/Caltech Cooperative Agreement G14AC00109 and SCEC, which is funded by NSF EAR-1033462 and USGS G12AC20038. E. H. and C. Y. were supported by SCEC, NSF EAR-1550704 and USGS/NEHRP: G16AP00147.Attached Files
Published - Yu_et_al-2017-Geophysical_Research_Letters.pdf
Supplemental Material - grl56415-sup-0001-2017GL075213_SI.docx
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Additional details
- Eprint ID
- 81688
- Resolver ID
- CaltechAUTHORS:20170921-124515276
- G14AC00109
- USGS
- Southern California Earthquake Center (SCEC)
- EAR-1033462
- NSF
- G12AC20038
- USGS
- EAR-1550704
- NSF
- G16AP00147
- USGS
- Created
-
2017-09-21Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory, Division of Geological and Planetary Sciences