HR: 08:45h
AN: T21C-04    [Abstracts]
TI: Lithospheric Thickness Modeled From Long Period Surface Wave Dispersion
AU: * Pasyanos, M E
EM: pasyanos1@llnl.gov
AF: Lawrence Livermore National Laboratory, L-205 P.O. Box 808, Livermore, CA 94551, United States
AB: The behavior of surface waves at long periods is indicative of subcrustal velocity structure. Using recently published dispersion models, we invert surface wave group velocities for lithospheric structure, including lid velocity and lithospheric thickness, over much of the Eastern Hemisphere, encompassing Eurasia, Africa, and the Indian Ocean. Thicker lithosphere keels and faster upper mantle velocities under Precambrian shields and platforms are clearly observed, not only under the large cratons (West African Craton, Congo Craton, Baltic Shield, Russian Platform, Siberian Platform, Indian Shield, Kalahari Craton), but also under smaller blocks like the Tarim Basin and Yangtze Craton. There are also interesting variations within cratons like the Congo Craton. As expected, the thinnest lithospheric thickness is found under oceanic and continental rifts, and also along convergence zones. We compare our results to thermal lithospheric models of the continents, lithospheric cooling models of oceanic lithosphere, lithosphere-asthenosphere boundary (LAB) estimates from S-wave receiver functions, and velocity variations of global tomography models.
DE: 7218 Lithosphere (1236)
DE: 8031 Rheology: crust and lithosphere (8159)
DE: 8103 Continental cratons
DE: 8138 Lithospheric flexure
DE: 8180 Tomography (6982, 7270)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting