HR: 0800h
AN: G21A-0104    [Abstracts]
TI: Dynamics of Deformation in Asia from a Combined GPS Solution and Finite Element Models
AU: * Dong, L
EM: ldong@purdue.edu
AF: Purdue University, EAS Dpt., West Lafayette, IN 47907 United States
AU: Wang, M
EM: mwang@gps.ac.cn
AF: Institute of Earthquake Sciences, CEA, Beijing, 100063 China
AU: Calais, E
EM: ecalais@purdue.edu
AF: Purdue University, EAS Dpt., West Lafayette, IN 47907 United States
AU: Shen, Z
EM: zshen@xena.ess.ucla.edu
AF: Institute of Geology, CEA, Beijing, 100029 China
AU: Vergnolle, M
EM: mvergnolle@usgs.gov
AF: USGS, 345 Middlefield, Menlo Park, CA 94025 United States
AB: The ability of plate tectonics concepts to describe deformation of large continental areas like Asia or the Western United States is subject to much debate. End-member models assume that continents deform either by rigid motion of lithospheric blocks along narrow fault zones or by viscous flow as continuously deforming solids. Discriminating these end-member models requires spatially dense measurements of surface strain rates covering the whole deforming area, including areas outside the obvious active faults and plate boundary zones. We present new results on present-day crustal deformation of Asia based on a combination of GPS solutions covering the entire deforming domain, including southeast Asia, China, Mongolia, and the Baikal rift zone. We discuss whether present-day surface displacements in Asia are best described by the motion of a limited number of rigid blocks or by diffuse deformation. We use the GPS results to validate dynamic deformation models aimed at better understanding the force balance that drives continental deformation in Asia. Major features of the best-fit models include (1) the importance of buoyancy forces in driving continental deformation, (2) localized deformation on major active faults, and (3) a good match of predicted fault slip rates with observed Holocene rates, except for the Altyn Tagh and Karakorum faults.
DE: 7223 Seismic hazard assessment and prediction
DE: 8107 Continental neotectonics
DE: 1208 Crustal movements--intraplate (8110)
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting