HR: 0800h
AN: V51B-0556    [Abstracts]
TI: Tomographic Images of the Yellowstone Hotspot Structure
AU: * Jordan, M
EM: mjordan@mines.utah.edu
AF: University of Utah, 135 South 1460 East, Salt Lake City, UT 84103 United States
AU: Smith, R B
EM: rbsmith@mines.utah.edu
AF: University of Utah, 135 South 1460 East, Salt Lake City, UT 84103 United States
AU: Waite, G P
EM: waite@usgs.gov
AF: USGS, 345 Middlefield Road, Menlo Park, CA 94025 United States
AB: The Yellowstone hotspot has extensive and youthful caldera forming volcanism, very high heatflow and significant gravity and geoid field anomalies. It is considered as a notable example of a continental plume. The existence of a plume beneath Yellowstone has been questioned and debated. We present the results of a high resolution 3D teleseismic tomography study that images the upper mantle beneath Yellowstone down to ~800 km depth. Because the delaytime tomography usually suffers from poor near surface resolution, the inversion is constrained by {\it a priori information}, including a large upper crustal low-velocity structure, the topography of the Moho, and the 410 and 660 km mantle discontinuities. Our derived model is consistent with various data sets and models for the Yellowstone region. In addition, long wave-length Bouguer gravity data is used as additional constraints, which are incorporated into the inversion via a joint inversion approach. Our modeling has resolved a region of low upper mantle velocity extending into, but not below, the transition zone. The results are discussed in terms of plumes and consistency with global models.
DE: 8450 Planetary volcanism (5480)
DE: 8121 Dynamics, convection currents and mantle plumes
DE: 7207 Core and mantle
DE: 3640 Igneous petrology
DE: 1025 Composition of the mantle
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting