HR: 0800h
AN: S41C-1031    [Abstracts]
TI: Tomographic Imaging of Upper Mantle P- and S-wave Velocity Heterogeneity Beneath the Arabian Peninsula
AU: * Park, Y
EM: ypark@geosc.psu.edu
AF: Department of Geosciences, Pennsylvania State University, University Park, PA 16802 United States
AU: Nyblade, A A
EM: andy@geosc.psu.edu
AF: Department of Geosciences, Pennsylvania State University, University Park, PA 16802 United States
AU: Rodgers, A
EM: rodgers7@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 United States
AU: Al-Amri, A
EM: amri444@yahoo.com
AF: Seismic Studies Center and Geology Department, King Saud University, Riyadh, 11451 Saudi Arabia
AB: We have studied the three-dimensional P- and S-wave velocity structure beneath the Arabian Peninsula estimated from teleseismic travel time delay tomography. We have completed travel time measurements and inversion of a data set provided by King Abdulaziz City for Science and Technology (KACST: 21 broadband stations and 4 short-period stations). We augmented the KACST data with delay times measured from permanent Incorporated Research Institutions for Seismology (IRIS) stations in the region (RAYN, EIL and MRNI) and the 1996 Saudi Arabian PASSCAL Experiment (9 broadband stations). We used 401 earthquakes resulting in 3416 ray paths with P- and PKP-wave arrivals for the P-wave tomography, and 1602 ray paths with S- and SKS-wave arrivals came from 201 earthquakes for the S-wave tomography. Although the total number of rays for the S-wave model is a half of the rays for the P-wave model, the event distribution shows better azimuthal coverage. The P and S wave models yield consistent results. The models show strong low velocity regions beneath the southeastern Arabian Shield and the mid-eastern edge of Arabian Shield. The low velocity anomaly in the southeastern part of the Arabian Shield does not extend north of 21°N and dips to south. It likely represents the northeastern edge of the Afar hotspot. The origin of the low velocity region under the eastern edge of the Arabian Shield is uncertain.
DE: 0545 Modeling (4255)
DE: 7203 Body waves
DE: 7208 Mantle (1212, 1213, 8124)
DE: 7270 Tomography (6982, 8180)
DE: 7290 Computational seismology
SC: Seismology [S]
MN: Fall Meeting 2005