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Portland Bureau of Emergency Management

Readiness. Response. Recovery.

Phone: 503-823-4375

Fax: 503-823-3903

TDD: 503-823-3947

Event Calendar

Upcoming events in the community to get better prepared for and informed about disasters.


Volcano Views and Brews

Loowit Brewing, 507 Columbia St, Vancouver WA

Tuesday, March 18 2014, 5:00 PM to 8:00 PM

Summary

http://mshinstitute.org/index.php/events/index

Category

Event Types > Community Events

Description

Presented by the Mount St. Helens Institute

Description: At the close of the last ice age, 15,000-20,000 years ago, a lobe of ice flowing south from Canada blocked the Clark Fork River in northwestern Montana. The resulting ice-dammed lake, known to geologists as glacial Lake Missoula, was at times more than 2000 feet deep and contained 500 cubic miles of water—20 times the size of Puget Sound. The ice dam ruptured and reformed dozens of times, each break-out sending torrents of water across eastern Washington and down the Columbia River. The flood waters were in places 1000 feet deep and flowing at 30 or 40 miles per hour, lifting boulders the size of automobiles and tumbling them downstream. With such force, these humongous floods instantaneously shaped the landscape of the Pacific Northwest by carving the channeled scablands, depositing bars of sand and gravel 100s of feet high, and backfilling broad valleys with silt and clay. But the floods also shaped the science of geology. When these floods were first proposed by early geologist J Harlen Bretz, such catastrophes were loathed by geologists confined by an intellectual framework of slow gradual processes shaping the planet over millions of years. The debate raged for decades, with many twists and turns. In the end Bretz prevailed, but surprising findings continue to emerge, challenging our understanding of one of the greatest natural events in earth history.

 

Jim O’Connor is a Pacific Northwest native long interested in the processes and events that shape the remarkable and diverse landscapes of the region. Following this interest with a Geological Science major at University of Washington and M.S. and Ph.D. degrees at University of Arizona, he has spent the last 20 years focused on the “science of scenery” (as ascribed to the field of geomorphology), for the last 15 years with the U.S. Geological Survey Water Science Center in Portland, Oregon.