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Bill Normark Interview: A Huge Glacial Flood that Traveled Far Beneath the Sea
When ancient glacial Lake Missoula burst through its dam 15,000 years ago, ten times the volume of all the rivers on Earth plunged down the Columbia River drainage. PBS producer Alison Kartevold interviewed USGS scientist Bill Normark on October 31st about where the floodwaters went when they hit the sea. Bill and colleagues discovered Lake Missoula flood deposits in Escanaba Trough about 250 km off the coast of Northern California. The discovery means that part of the ancient floodwaters traveled a distance of at least 1,100 km along the sea floor as hyperpycnally generated turbidity currents before being trapped in the box-canyon topography of Escanaba Trough. In this sense, the turbidity currents left a submarine flood record similar to records left by their terrestrial counterparts, which flowed back up tributaries of the Columbia River. Alison has been working with USGS scientist Richard Waitt to document onshore evidence of the flood. She hopes to broadcast the hour-long program in March 2001. (For more information about Bill's research, see Normark, W.R., and Reid, J.A., 2003, Extensive deposits on the Pacific plate from late Pleistocene North American glacial lake outbursts: Journal of Geology, v. 111, no. 6, p. 617-637 [URL http://www.journals.uchicago.edu/doi/abs/10.1086/378334].)
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in this issue: Santa Rosa Island
cover story: Nat'l Geography Awareness Week Lake Tahoe: "Wonders of the Universe" Calendar Plymouth County Detention Center Bill Normark Interview Geologic Framework of U.S. Coastal & Marine Regions Southwest Washington Coastal Erosion Southeatern U.S. Benthic Habitat Southern California Benthic Habitat 9th International Coral Reef Symposium |