Dr. Jerome Lesemann Presents “Subglacial/proglacial mega floods from the Cordilleran Ice Sheet on the Channeled Scablands”

Glacial Lake Missoula is most commonly invoked as the sole source of water to form the Channeled Scabland. However, early work by Bretz (and others) suggested more direct contributions of meltwater from the Cordilleran Ice Sheet to explain formation of some Scabland flood tracts. In some cases, these contributions may have been subglacially routed.

This presentation will examine new research on Moses Coulee – one of the more enigmatic Scabland coulees – that suggests subglacial meltwater flows best explain the erosional patterns of the coulee and its perplexing lack of connectivity to other Scabland flood routes. Further, the presentation will examine new evidence for proglacial (Mega) floods during deglaciation of the Cordilleran Ice Sheet that may also contribute to formation of flood features such as giant bars along the Columbia River Valley. The presentation highlights the need for greater integration of Cordilleran Ice Sheet hydrology in the interpretive framework of the Channeled Scabland. As a workup to this presentation please familiarize yourself with the IAFI News article, “Moses Coulee: Unveiling the Mystery of a Colossal Ice Age Scar“, that gives an overview on this subject.

Dr. Jerome Lesemann obtained his PhD from Simon Fraser University. He currently teaches in the Earth Science Department at Vancouver Island University in Nanaimo, BC. His research interests are in Quaternary geology and sedimentology with a focus on glacier processes and ice sheet hydrology. He has had an interest in the Channeled Scabland for over two decades, with a particular focus on the dynamics of the Cordilleran Ice Sheet along the northern reaches of the Channeled Scabland.

Date: 20 May 2024 at 7:00pm
Location: Bellevue College, Bldg. R, Rm. 103
or click on Zoom link:   https://us02web.Zoom.us/j/82985244730