HR: 17:30h
AN: V14B-07 INVITED     [Abstracts]
TI: Tectonic and magmatic stress interaction of the Yellowstone volcanic system
AU: * Smith, R B
EM: r.smith@earth.utah.edu
AF: University of Utah, 135 S. 146 East, Rm 702, Salt Lake City, UT 84112 United States
AU: Chang, W
V14B-07 AF: University of Utah, 135 S. 146 East, Rm 702, Salt Lake City, UT 84112 United States
AU: Puskas, C
V14B-07 AF: University of Utah, 135 S. 146 East, Rm 702, Salt Lake City, UT 84112 United States
AU: Farrell, J
V14B-07 AF: University of Utah, 135 S. 146 East, Rm 702, Salt Lake City, UT 84112 United States
AB: Fault-stress interaction is a well-known mechanism for triggering of earthquakes by nearby faulting. This phenomenon was observed following the 1959 M 7.5 Hebgen Lake MT earthquake, located on the NW periphery of the Yellowstone caldera, that triggered a protracted period, tens of years, of aftershock activity both inside and outside the caldera. What is not known is how such triggering affected the state stress of the Yellowstone magmatic system. Examination of long-term trends in caldera deformation at decadal periods revealed changes of uplift to subsidence and back to uplift that seem to correspond to notable changes in seismicity. Moreover, moderate sized earthquakes have in some cases triggered hydrothermal activity. A recent episode of asymmetric caldera uplift, with rates up to 5 cm/yr from mid 2004 to present, Sept. 2005, provides data to test the correlation between earthquake behavior and rapid crustal deformation. Spatial and temporal changes in deformation rates from permanent GPS stations will be used to examine mass change in Yellowstone's mid crustal magma system and the shallower hydrothermal system. Elastic and visco-elastic models of time and spatial behavior of Yellowstone fault and volcano features will be examined to address these questions.
DE: 1242 Seismic cycle related deformations (6924, 7209, 7223, 7230)
DE: 7280 Volcano seismology (8419)
DE: 8424 Hydrothermal systems (0450, 1034, 3017, 3616, 4832, 8135)
DE: 8434 Magma migration and fragmentation
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005