Sponsored by : Montgomery and Associates
Megafloods on Earth, Mars, and Beyond
by Victor R. Baker
Abstract: Megafloods (terrestrial water flows with discharges exceeding one million cubic meters per second) are the largest known freshwater floods, with flows comparable in scale to (though of shorter duration than) ocean currents. Although there are no modern examples of megafloods, such flows occurred during major periods of glaciation. A prominent example is the paleoflooding caused by late Pleistocene outbursts from Glacial Lake Missoula, which formed when the Purcell Lobe of the Cordilleran Ice Sheet extended south from British Columbia to the basin of modern Pend Oreille Lake in northern Idaho. The ice thereby impounded the Clark Fork River drainage to the east, forming a lake extending into western Montana with a water volume of about 2500 cubic kilometers and a depth of 600 m at the dam. The largest Lake Missoula outbursts were in the range of 10 to 20 sverdrups (one sverdrup equals one million cubic meters per second) and involved flows that lasted for several days. The Missoula Floods were responsible for generating the Channeled Scabland of east-central Washington state -- a complex of anastomosing rock-cut fluvial channels, cataracts, loess “islands,” rock basins, broad gravel deposits, and immense gravel bars. These flows deeply inundated the Columbia Gorge and the Willamette Valley before discharging into the eastern Pacific Ocean. Other late-glacial megafloods occurred along the margins of the great ice sheets that formed during the Pleistocene in North America, Eurasia, and southern South America (Patagonia). The greatest known megafloods of water occurred on the planet Mars, where the immense outpourings resulted in temporary bodies of water, even generating a kind of ocean that facilitated environmental conditions on Mars that may have been similar to those of an ice-age on Earth. These discoveries are showing that Mars, like Earth, had a long-term cycle of water circulation that produced a habitable planet, and these are exactly the kinds of processes to seek out in the newly initiated search for the other habitable planets of the universe.
Bio: Victor R. Baker is Regents’ Professor of Hydrology and Water Resources, Professor of Geosciences, and Professor of Planetary Sciences, The University of Arizona. His B.S. in geology is from Rensselaer Polytechnic Institute (1967) and his Ph.D. in geology is from the University of Colorado (1971). Professor Baker has authored or co-authored about 400 research papers and chapters and authored or edited 18 books on topics that include the geology and paleohydrology of Mars, Quaternary paleohydrology and geology, flood geomorphology, and history/philosophy of Earth and planetary sciences. He has been President of the Geological Society of America (1998), and he has chaired that society’s Divisions for History and Philosophy of Geology (2010), Quaternary Geology and Geomorphology (1987), and Planetary Geology (1986). He has also served as Chair of the American Association for the Advancement of Science Section on Geology and Geography (1992-93 and 2008-2009). Among his honors are Foreign Membership in the Polish Academy of Sciences (1994); Honorary Fellowship in the European Union of Geosciences (1999); the David Linton Award of the British Society for Geomorphology (1995); the Distinguished Scientist Award (2002) and Distinguished Career Award (2010), both from The Geological Society of America Quaternary Geology and Geomorphology Division; a Fulbright-Hays Senior Research Fellowship; an Indo-American Fellowship; and professional society Fellowships respectively in the American Geophysical Union, theAmerican Association for the Advancement of Science, The Geological Society of America, and the British Society for Geomorphology. Dr. Baker was the Inaugural International Lecturer for The Geological Society of America, delivering 25 lectures on the topics of Megafloods on Earth, Mars, and Beyond and Geological History of Water onan Earth-like Planet at 23 academic venues in England, Scotland, Finland, Sweden, Ireland, The Netherlands, Italy, Israel, Germany, France, Spain and Turkey; including the universities of Cambridge, Edinburgh, Helsinki, Nantes, Paris, Utrecht, Parma, and Bologna; Hebrew Univesity of Jerusalem; Istanbul Techncial University; Imperial College (London); Uppsala Unverisity; the Museum of Natural Sciences (Madrid); Universidad Complutense de Madrid; Universita d’Annunzio (Italy); Trinity College (Dublin); Ludwig-Maxmillians University (Munich); and the Academia Lincei (Rome). His work on megafloods has been featured in multiple television documentaries for PBS, BBC, and the National Geographic, Discovery, and History Channels, including the 2005 NOVA production “Mystery of the Megaflood.”