From the Last Glacial Maximum to Present: New Chronologies for Oregon’s Cascade Ice Cap and Glaciers

Anders Carlson

Oregon Glaciers Institute

5:30 pm social hour

7:00 pm presentation

During the last ice age an ice cap covered much of the Oregon Cascade crest, with a north-south length roughly between that of the modern Northern and Southern Patagonia ice caps. Oregon’s ice cap stands out from other late Pleistocene ice bodies in the western United States in that its deglacial history is largely unknown. Here, we will present new Helium-3 surface exposure ages for the ice cap collected from the Three Fingered Jack and Middle Sister regions. These ages will directly date when it retreated from its last glacial maximum extent and then paused to deposit moraines close to late Holocene/historical moraines. This new chronology will allow us to relate ice-cap change to regional climate change as recorded in marine and cave temperature records. We will also have new Helium-3 ages for potential prehistoric late-Holocene moraines just outboard of historic moraines from Hayden Glacier on Middle Sister and Eliot Glacier on Mount Hood. In sum, these new ages will expand the record of cryospheric change in Oregon from less than the last 150 years, to likely more than the last 20,000 years.

Please join us at Bridge 99 Brewery:

63063 Layton Avenue, Bend

5:30 pm social hour

7:00 pm presentation

COGS talk are free and open to the public -- all are welcome! Please join us for the social hour before the presentation.

All presentations are also live-streamed through Zoom. There will be a registration link at the top of this page as we get closer to the date of this presentation.