View Local Events
- This event has passed.
Moses Coulee Megafloods
October 12 @ 7:00 pm - 8:00 pmFree
The Wenatchee Valley Erratics, Ice Age Floods Institute’s next ZOOM program will be on Tuesday, October 12 at 7:00 PM. Joel Gombiner, PhD candidate at U. of Washington will discuss “Moses Coulee Megafloods.”
Moses Coulee is unique from other Scabland canyons because it lacks an obvious tie-in to the Columbia River. It heads in the middle of the Waterville Plateau, but lacks clear feeder channels or flood-scoured surfaces that link to the Columbia River. How did it get there? How was it formed? And when?
J Harlen Bretz (1950s) suggested the connection between Moses Coulee and the Columbia River was eroded by Okanogan Lobe glaciation, and/or buried by glacial sediments.
Larry Hanson, (1970s), identified the Mansfield Channels—low-relief channels on the Waterville Plateau—and argued these features carried water from the Columbia to the head of Moses Coulee.
In 2009, Canadians Jerome Lesemann and Tracy Brennand published evidence for sub-glacial flooding in the Canadian Okanagan, and proposed that subglacial floods drained directly into Moses Coulee.
Using field observations and laboratory analyses of rocks and minerals transported by the megafloods, Joel will present new, unpublished data using megaflood deposits in the Coulee that suggest it formed before the last glaciation, that it flooded prior to the Grand Coulee during the last glaciation, and that Lake Missoula was a flood source for at least some, but not all, Moses Coulee floods.
ZOOM link: https://us02web.zoom.us/j/86226617396