HR: 0800h
AN: G21C-0664    [Abstracts]
TI: Mechanics and Partitioning of Deformation of the Northwestern Okhostk Plate, Northeast Russia
AU: * Hindle, D
EM: dhindle@ifm-geomar.de
AF: Geologisches Institut Universitaet Freiburg, Albertsrasse 23b, Freiburg, 79104, Germany
AU: Mackey, K
EM: mackeyke@msu.edu
AF: Dept. of Geol. Sci. Michigan State University, 206 Nat. Sci. Building, East Lansing, MI 48824, United States
AU: Fujita, K
EM: fujita@msu.edu
AF: Dept. of Geol. Sci. Michigan State University, 206 Nat. Sci. Building, East Lansing, MI 48824, United States
AB: The tectonic evolution and present day deformation of northeastern Russia remains one of the major challenges in plate tectonics. Arguments over the existence of at least a separate Okhotsk plate between North America and Eurasia appear to be resolved on the basis of the latest GPS studies combined with elastic modeling. The question of the mechanical behaviour of the Okhotsk plate, caught between the slowly, obliquely converging North American and Eurasian plates now becomes important. We present an analysis of geological lineaments, micro-seismicity, total seismic moment release and seismic deformation rate and GPS campaign data and global plate tectonic model data (REVEL) to estimate the likelihood of future seismicity and the relative amount of elastic and viscous deformation of the lithosphere of the northwestern Okhotsk plate. We find that it is likely that the Okhotsk plate is cracked into slivers, but that rates of relative motion of these slivers are close to indistinguishable from the behaviour of a single, rigid plate. The analysis also suggests the upper bound for large earthquakes in the region to be Mw 7-7.5 which we expect to occur only on the plate boundary fault itself. This fits geological evidence for a long term offset rate 5-10 times higher on the major plate boundary fault than other lineaments cutting the Okhotsk plate itself.
DE: 1209 Tectonic deformation (6924)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 8108 Continental tectonics: compressional
DE: 8111 Continental tectonics: strike-slip and transform
DE: 8175 Tectonics and landscape evolution
SC: Geodesy [G]
MN: 2007 Fall Meeting