HR: 16:20h
AN: T34A-02    [Abstracts]
TI: Crust-Mantle Interaction and Tectonic Stress: A Multi-Data Analysis and Modeling to Investigate Large Earthquakes in the SE Carpathians
AU: Mueller, B
EM: Birgit.Mueller@gpi.uni-karlsruhe.de
AF: Geophysical Institute, University of Karlsruhe, Hertzstr. 16, Karlsruhe, 76187 Germany
AU: * Ismail-Zadeh, A
EM: Alik.Ismail-Zadeh@gpi.uni-karlsruhe.de
AF: Geophysical Institute, University of Karlsruhe, Hertzstr. 16, Karlsruhe, 76187 Germany
AU: * Ismail-Zadeh, A
EM: Alik.Ismail-Zadeh@gpi.uni-karlsruhe.de
AF: Intl Institute of Earthquake Prediction Theory and Math Geophysics, Russ. Acad. Sc., Warshavskoye sh. 79-2, Moscow, 113556 Russian Federation
AU: Schubert, G
EM: schubert@ucla.edu
AF: Department of Earth & Space Sciences and Institute of Geophysics and Planetary Physics, UCLA, 3806 Geology Building, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 United States
AB: The principal purpose of the study is to understand the interplay between intermediate-depth large earthquakes in the SE-Carpathians (Vrancea) and tectonic stress within a high-velocity body (lithospheric slab) descending into the mantle. To analyze processes of stress generation and localization in and around the descending slab, we develop a 3D numerical model of contemporary mantle flow and stress beneath the Vrancea region. The input data of the model consist of (i) temperatures derived from seismic P-wave velocity anomalies and surface heat flow, (ii) crustal and uppermost mantle densities converted from P-wave velocities obtained from seismic refraction studies, (iii) geometry of the Vrancea crust and slab from tomography and refraction seismic data, and (iv) the estimated strain rate in the slab (as a result of earthquakes) to constrain the model viscosity. Major crustal uplifts predicted by the model coincide with the East Carpathian orogen and surround the Transylvanian basin, and predicted areas of subsidence are associated with the Moesian and East European platforms. The location of intermediate-depth earthquakes coincides with the predicted localization of maximum shear stress. Modeled tectonic stresses predict large horizontal compression at depths of about 70 to 220 km beneath the Vrancea region, which coincides with the stress regime derived from fault-plane solutions for the intermediate-depth earthquakes. This implies that the buoyancy-driven descent of the lithospheric slab beneath the Vrancea region is directly linked to intermediate-depth seismicity.
DE: 9335 Europe
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8164 Stresses--crust and lithosphere
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting