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 A cross section of the earth beneath Yellowstone reveals molten rock under a large caldera at depths of about 3–5 miles. Heat emitted by the magma powers Yellowstone’s famous geysers and hot springs. From Windows into the Earth: The Geologic story of Yellowstone and Grand Teton National Parks by Robert B. Smith and Lee J. Seigel, copyright 2000 by Robert B. Smith and Lee J. Seigel. Used by permission of Oxford University Press, Inc.
Tom Olliff
Back to Chapter 3: National Parks as Laboratories Articles Urban refuge for rare amphipods in the National Capital Region By Diane Pavek Finding our hidden biodiversity By Becky Nichols and Keith Langdon Rest from grazing at Chaco By Annie Esperanza and Judy Rocchio Lessons from the 1988 Yellowstone fires By Tami Blackford and Mary Ann Franke Other Developments Parks for science Journey into Amazing Caves premieres |
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 By Tom Olliff The spectacular geysers, boiling hot springs, and mud pots that have made Yellowstone National Park famous owe their existence to volcanic activity that has affected the region during the past 2 million years. Cataclysmic explosive eruptions 2.0, 1.3, and 0.6 million years ago ejected huge volumes of molten rock and formed large, overlapping, elliptical depressions called calderas. This energy also created the mountains and canyons, and generates the unique ecosystems that support Yellowstone’s diverse wildlife today. With a little help from interpreters, park visitors do not have to look very hard to understand that Yellowstone and the surrounding area encompass the largest active magmatic system in North America. To strengthen the long-term monitoring of volcanic and earthquake unrest in the Yellowstone National Park region, the USGS, Yellowstone National Park, and the University of Utah agreed in 2001 to establish the Yellowstone Volcano Observatory. The new partnership will improve collaborative study and monitoring of active geologic processes and hazards of the Yellowstone volcanic field and its caldera, site of the largest and most diverse collection of natural thermal features in the world. It will also facilitate better interpretation of geologic events because park staff can access real-time data on-line. “The new observatory will improve our efforts to monitor Yellowstone’s extraordinarily large and long-lived volcanic system,” said Dr. Robert L. Christiansen, USGS scientist-in-charge of the new observatory. “This agreement is a natural evolution of our collective work over the years to track and study Yellowstone’s unrest.” The new observatory is modeled after the other USGS volcano observatories in Alaska, California, the Pacific Northwest, and Hawaii. Together, they monitor 43 of the 70 or so potentially hazardous volcanoes in the United States. The observatories are operated under the auspices of the USGS Volcano Hazards Program. Operations for the Yellowstone Volcano Observatory will be based at existing facilities at the University of Utah and Yellowstone National Park. Ground-based instruments and satellite data are used for real-time monitoring of active and restless volcanoes, including a modern digital seismic and global positioning system (GPS) network, operated for many years by the University of Utah Seismograph Stations under a cooperative funding agreement with the USGS and with additional support from the National Park Service. The partners also monitor ground deformation using portable leveling stations and a continuously recording GPS network. “The extensive thermal features of Yellowstone are fueled by heat from magma beneath the caldera that in turn is fed from a magma reservoir in the Earth’s deep interior called a hotspot, a significant feature in plate tectonics,” said Dr. Robert B. Smith, University of Utah coordinating scientist of the observatory. “In the past we’ve measured the rise of the ground by as much as 3 feet and fall by a foot across the youngest caldera. This active deformation was accompanied by thousands of small earthquakes, marking the park as a living geologic system.” The Yellowstone region also is seismically active today. The 1959 magnitude-7.5 Hebgen Lake earthquake, centered just outside the park’s northwestern boundary, was the largest earthquake in the western interior in U.S. history and caused 28 fatalities. Hydrothermal eruptions are also a concern. Since deglaciation almost 14,000 years ago, scientists estimate that 6 to 10 large hydrothermal eruptions have occurred in Yellowstone, blowing tons of debris into the air and forming such modern-day features as Indian Pond and Turbid Lake. Christiansen emphasizes: “There is no increased threat of eruptive activity at Yellowstone to cause concern at this time. We hope to use the observatory to share even more of what we are learning with the public … and to be in a better position to provide warning of any future hazardous activity.” Additional information about the Yellowstone Volcano Observatory is available on the Web (http://volcanoes.usgs.gov/yvo). |
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This material is from Natural Resource Year in Review--2001, published by the National Park Service, U.S. Department of the Interior, in May 2001 (publication D-2255) /YearInReview/yir/yir2001/03_laboratories/03_2_oliff.html Last Updated: |
