HR: 09:25h
AN: G31D-06 INVITED     [Abstracts]
TI: A new strain rate model for the Great Basin and its application to tectonic and geodynamic studies
AU: * Kreemer, C
EM: kreemer@unr.edu
AF: Nevada Bureau of Mines and Geology, University of Nevada, MS 178, Reno, NV 89557 United States
AU: Blewitt, G
EM: gblewitt@unr.edu
AF: Nevada Bureau of Mines and Geology, University of Nevada, MS 178, Reno, NV 89557 United States
AU: Hammond, W C
EM: whammond@unr.edu
AF: Nevada Bureau of Mines and Geology, University of Nevada, MS 178, Reno, NV 89557 United States
AU: Coolbaugh, M F
EM: mfc@unr.nevada.edu
AF: Great Basin Center for Geothermal Energy, University of Nevada, MS 172, Reno, NV 89557 United States
AB: The Great Basin in the western United States covers a large portion of the diffuse PA-NA plate boundary zone. Yet the seismic potential of its many faults as well as the evolution of, and the driving forces behind, the deformation remain largely unknown or disputed. To advance our understanding it is important to quantify the spatial distribution of the rate, style and direction of the present-day deformation field. GPS velocity measurements are the single most important input to fulfill this objective, and many data are now available from continuous (e.g., BARGEN network) and campaign style measurements (USGS and others). We use the Haines and Holt technique to present a new strain rate model, which is superior in its use of the latest GPS solutions and a denser model grid. Furthermore, the release of the 2003 USGS fault database makes it possible to use geologic data (i.e., slip rate and/or fault geometry) either as an additional constraint in or as a comparison with models based on the interpolation of GPS velocities alone. The ultimate aim of this work is; 1) to compare present-day style and rate of deformation with finite strain markers to place constraints on the Quaternary evolution of deformation, particularly in the northern Walker Lane, 2) to use objective means in distinguishing potential rigid blocks, 3) to identify zones of transient deformation, 4) to further develop the observed relationship between shear strain rate, fault orientation and geothermal output, and 5) to improve geodynamic models by comparing modeled present-day strain rate directions with finite strain orientations in the middle to lower crust as shown in metamorphic complexes and in the lithosphere as inferred from seismic anisotropy. For this presentation we will discuss the data synthesis as well as the resolution and reliability of the model. Furthermore, a few examples will be highlighted to underline the potential of the model in addressing the goals described above. Finally, a brief introduction will be given to the semi-permanent Mobile Array of GPS for NEvada Transtension (MAGNET) network (currently 40-50 stations, and growing) that will greatly improve our spatial resolution and velocity precision in the western Great Basin.
DE: 8109 Continental tectonics--extensional (0905)
DE: 8123 Dynamics, seismotectonics
DE: 8150 Plate boundary--general (3040)
DE: 1208 Crustal movements--intraplate (8110)
DE: 1243 Space geodetic surveys
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting