with Sidney Hemming and Joel Gombinder
Originally presented 8 Feb 2014
In the 19th Century, geologists realized that much of our planet was once covered by huge ice sheets. At times while they melted back to the existing continental glaciers, the melt waters were blocked and formed lakes that covered places which are now dry land. Some of these lakes were small, but some were bigger than today’s Great Lakes. At various points during the de-glaciation process, dams holding the glacial lakes broke and produced catastrophic floods.
How do we know these things? What can they tell us about Earth’s past history? Dr. Sidney Hemming will share with us results from her research about “Massive Glacial Lake Flooding.”
Dr. Hemming serves as Professor in Columbia’s Department of Earth and Environmental Sciences, specializing in Geochemistry. She directs the Argon Geochronology for the Earth Sciences (AGES) lab (http://www.ldeo.columbia.edu/res/fac/argon/Home.html). Dr. Hemming’s field of research include geochronology, sedimentary geochemistry, paleoclimate, and continental crust evolution.
“I consider my field to be Historical Geology. Using the record from sediments and sedimentary rocks, I seek to document aspects of Earth’s history. Understanding the provenance and processes recorded in the geochemistry of sediments and sedimentary rocks lies at the heart of my research interests. I have strong interest in tectonics and continental crust evolution questions on the longer time scale. I have an active program of applying radiogenic isotopes for tracing the sources of sediments with the goal of understanding Quaternary climate changes and associated changes in winds, currents and glaciers. Provenance studies of ice rafted detritus are key to working out the dynamic relationships among paleo-climate and paleo-ocean circulation and their interactions with the large ice sheets that covered the northern continents during the ice ages. Geochronology is essential to my research and I am actively participating in projects to improve our ability to obtain reliable age estimates on events in Earth’s history.”
Joel Gombinder works with Dr. Hemming in the lab and field. He has studied the Glacial Lake Missoula flood extensively, and continues field-based research to discover more about this event.
Previous Earth2Class Workshop
“Lake Level History of the Mono Lake Basin, eastern CA” http://earth2class.org/k12/w3_f2012/index.php
Introductory Slideshow
“Hemming_Massive_Glacial_Flooding” (created by Michael J Passow)
Classroom Resources
Ice Age Floods Institute (focus on glacial flooding in the Pacific Northwest)
National Park Service Tours of Glaciers and Glacial Geology in the Parks
NOVA: Mystery of the Megaflood
To Learn More about the Science:
Glacial Lake Missoula and the Ice Age Floods: Virtual Tour
Rudoy, A.N., and V.R. Baker, “Sedimentary Effects of Cataclysmic Late Pleistocene Glacial Outburst Flooding“
Multimedia Files from Dr. Hemming’s Presentation
