Vp/Vs ratios in the Yellowstone National Park region, Wyoming
In this paper we study the variation of Vp/Vs and Poisson's ratio (??) in the Yellowstone National Park region, using earthquakes which were well recorded by a local seismic network. We find that the average Vp/Vs value within the geothermally active Yellowstone caldera is about 7% lower than in the area outside the caldera. Within the caldera itself there may be a further 2-7% reduction of Vp/Vs in the hydrothermally active Norris Geyser Basin, the Upper and Lower Geyser Basins, and the Yellowstone Lake and Mud Volcano regions. After considering various possible causes for Vp/Vs changes, such as geologic and structural differences, thermal effects, partial melting, and hydrothermal activity, we conclude that the most plausible explanation for the observed Vp/Vs reduction is the presence of hot-water at temperatures and pore-pressures near the water steam transition in the caldera geothermal reservoirs. ?? 1985.
Citation Information
Publication Year | 1985 |
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Title | Vp/Vs ratios in the Yellowstone National Park region, Wyoming |
Authors | S.N. Chatterjee, A. M. Pitt, H.M. Iyer |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of Volcanology and Geothermal Research |
Index ID | 70013112 |
Record Source | USGS Publications Warehouse |