A Simultaneous Multi-phase Approach to Determine P-wave and S-wave Attenuation of the Crust and Upper Mantle
We have generalized the methodology of our regional amplitude tomography from the Lg phase to the four primary regional phases (Pn, Pg, Sn, Lg). Differences in the geometrical spreading, source term, site term, and travel paths are accounted for, while event source parameters such as seismic moment are consistent among phases. In the process, we have developed the first regional attenuation model that uses the amplitudes of four regional phases to determine a comprehensive P-wave and S-wave attenuation model of the crust and upper mantle. When applied to an area encompassing the Middle East, eastern Europe, western Asia, south Asia, and northeast Africa for the 1-2 Hz passband, we find large differences in the attenuation of the lithosphere across the region. The tectonic Tethys collision zone has high attenuation, while stable outlying regions have low attenuation. While crust and mantle Q variations are often consistent, we do find several notable areas where they differ considerably, but are appropriate given the region's tectonic history. Lastly, the relative values of Qp and Qs indicate that scattering Q is likely the dominant source of attenuation in the crust at these frequencies.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 970657
- Report Number(s):
- LLNL-JRNL-410961
- Journal Information:
- Bulletin of the Seismological Society of America, Journal Name: Bulletin of the Seismological Society of America Journal Issue: 6 Vol. 99; ISSN BSSAAP; ISSN 0037-1106
- Country of Publication:
- United States
- Language:
- English
Similar Records
Report on Depth-Dependent Q from Frequency-Dependent Lg Q
Improvements to Regional Explosion Identification using Attenuation Models of the Lithosphere