Group Research Links

• Yellowstone GIS: Information on the Yellowstone hotspot
• Wasatch Front Permanent GPS network
• Yellowstone-Snake-River-Plain Permanent GPS network
• A list of publications since 2000

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  Research Highlights

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  The Yellowstone Plume

  VP and VS structure of the Yellowstone hot spot from teleseismic tomography: Evidence for an upper mantle plume

  by Greg Waite, Robert Smith, and Richard Allen

  Published in Journal of Geophysical Research in April 2006

  The development of the 16 Ma Yellowstone-Snake River Plain volcanic system has been attributed to the North America lithosphere moving over a stationary mantle plume, but the plume itself remained unresolved because of a lack of seismic data. New seismic data now provide strong evidence for an upper mantle plume to depths of 450 km below the Yellowstone caldera and eastern Snake River Plain. Distant earthquakes were recorded on two temporary seismograph arrays operated from 1999-2003 in 500x600-km area centered on Yellowstone and analysed to obtain a model of seismic velocities beneath Yellowstone. The tomographyic analysis revealed a body with anomalously low seismic velocities in the upper mantle that tilted 30°, so that the body becomes offset to the north with increasing depth. These results are consistent with an upwelling of hot material (i.e., a plume) in the upper mantle. Furthermore, the tilting of the plume is consistent horizontal flow of mantle material interacting with the plume.

  More Information: Greg Waite's home page. A PDF of the article.

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  Unprecendented Uplift of Yellowstone

  Accelerated Uplift and Magmatic Intrusion of the Yellowstone Caldera, 2004 to 2006

  by Wu-Lung Chang, Bob Smith, Chuck Wicks, Jamie Farrell, and Christine Puskas

  Published in Science on November 09 2007

  The Yellowstone caldera began an extraordinary episode of ground rising in mid-2004, revealed by GPS (Global Positioning System) and InSAR (Interferometric Synthetic Aperture Radar) measurements, at rates up to 7 cm/yr that is over three times faster than previously observed inflation rates. The caldera-wide accelerated uplift is interpreted as magmatic recharge of the Yellowstone magma body. While the geodetic observations and models do not imply an impending volcanic eruption or hydrothermal explosion, they are important evidence of on going processes of a large caldera that was produced by a super volcano eruption.

  More Information: Map of Yellowstone and the GPS net work. The University of Utah press release. The Yellowstone Volcano Observatory. The article at Science.

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  History of Yellowstone Crustal Motions

  Crustal deformation of the Yellowstone-Snake River Plain Volcanic System: campaign and continuous GPS observations, 1987-2004

  by Christine Puskas, Robert Smith, Charles Meertens, and Wu-Lung Chang

  Published in Journal of Geophysical Research in March 2007

  The University of Utah conducted seven GPS campaigns at 140 sites in the Yellowstone-Snake River Plain volcanic system between 1987 and 2003 and installed a network of 15 permanent stations. Analysis of the GPS measurements revealed periods of uplift and subsidence at the Yellowton caldera. From 1987 to 1995, the caldera subsided at a maximum rate of 14 mm/yr. From 1995 to 2000, the center of deformation shifted to the north caldera boundary, which rose at up to 15 mm/yr. Subsidence resumed in the the calder between 2000 and 2003 at 9 mm/yr, while uplift continued at the north caldera boundary at 12 mm/yr. These rates contrast are an order of magnitude less than the accelerated uplift, which began in 2004. The caldera deformation was hypothesized to arise from the accumulation and release of brines or other fluids from the magma chamber. The study additionally measured extension across the caldera at 2-4 mm/yr and southwest motion of the eastern Snake River Plain at 2.1 mm/yr.

  More Information: A PDF of the article.

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  The Yellowstone Magma Chamber

  Evidence for gas and magmatic sources beneath the Yellowstone Volcanic Field from seismic tomographic imaging

  by Stephan Husen, Robert Smith, and Greg Waite

  Published in Journal of Volcanology and Geothermal Research in March 2004

  Local earthquake tomography was used to determine the P-wave and P-wave to S-wave velocity structure at Yellowstone National Park. A body with anomalously low P-wave velocities was found below the Yellowston caldera at depths greater than 8 km and interpreted to be a magma chamber of partially molten rock. Another anomaly of low Vp and Vp/Vs was found at shallow depths of 2 km at the northwest caldera boundary. This shallow anomaly is consistent with porous, gas-filled rock, with the gas probably being CO₂. The release of magmatic fluids such as CO₂ exsolved from the crystallizing magma may be associated with earthquake swarms in Yellowstone.

  More Information: A PDF of the article.

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  Who we are:

  Robert B. Smith Bob Smith's research interests are in seismology, tectonophysics, crustal deformation using GPS (Global Positioning System), and active tectonics. Current research projects include: 1) geodynamics of and evolution of the Yellowstone hotspot and the Yellowstone caldera, 2) seismicity and volcanic hazards of Yellowstone and operation of the Yellowstone seismograph network, and 3) crustal deformation and earthquake hazards of the Wasatch and Teton faults using GPS and fault modeling. Teaching includes tectonophysics and elastic waves, theoretical seismology, earthquake seismology and earthquake hazards, and introductory earthquakes and volcanoes.
  Wu-Lung Chang Postdoctoral fellow Wu-Lung Chang's most recent research has been focused on geodetic studies of active normal-fault systems and silicic volcanic fields, and earthquake hazard analysis, including (1) viscoelastic modeling for lithospheric rheology using the postseismic relaxation of the Ms=7.5 1959 Hebgen Lake, Montana, earthquake; (2) studying the inter-seismic kinematics of the Wasatch fault zone, Utah, and elastic modeling of fault geometry and loading rate; (3) crustal deformation and source modeling of the Yellowstone volcanic system; (4) integrating GPS observations with seismic and geologic data for earthquake ground shaking hazard analysis.
  Christine Puskas Christine Puskas is a Ph.D student working on the geodynamics of the western US interior and the effects of the Yellowstone hotspot. This research includes: 1) block and continuum modeling of deformation, 2) calculation of deviatoric stresses from variation in mass in the lithosphere, and 3) campaign GPS measurements of Yellowstone-Snake River Plain motion.
  Jamie Farrell Ph.D student Jamie Farrell's research interests are in seismology, tectonophysics, and geodynamics of the Yellowstone Hotspot. Current research projects include: 1) geodynamics of and evolution of the Yellowstone caldera using Finite Element Modeling, 2) seismicity and volcanic hazards of Yellowstone, and 3) the time-spatial seismicity patterns of the Yellowstone system characterized by the b-value.
  Katrina Settles Katrina Settles is a masters student whose research focuses on tectono-magmatic processes of the Yellowstone-Snake River Plain volcanic system. Just-completed research projects include gravity-density and lithospheric strength modeling of the YSRP. She will be working for ConocoPhilips starting in November 2007.

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  Other Links

  • Yellowstone Volcano Observatory
  • Yellowstone National Park
  • Earthscope Project
  • Plate Boundary Observatory
  • University of Utah Seismograph Stations
  • University of Utah Department of Geology and Geophysics
  • University of Utah

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  Last Update: August 1, 2008