Numerous moraines front the Coe Glacier on the north side of Mount Hood, Oregon. These moraines were identified and dated using a multiple methodology approach in order to establish a chronology for the advances and stillstands of the Cae Glacier. This chronology was compared to chronologies established for other glaciers on Mount Hood, North Sister, Mount Rainier and Mount Baker as well as glaciers in Scandinavia. The chronology was also compared to a long term temperature record from Longmire, Washington.
The maximum identified extent of the pre-Little Ice Age Coe Glacier was indicated by moraines located at an elevation of about 1530 m and about 2 km downvalley of the present terminus. A general period of shrinkage of the pre-Little Ice Age Coe Glacier followed resulting in the deposition of moraines upvalley of the older pre-Little Ice Age moraines.
The Little Ice Age Coe Glacier reached its maximum downvalley extent of about 1650 m elevation prior to 1731 AD. An earlier advance (1607 AD) was more extensive laterally than the 1731 AD advance. The Coe Glacier has been in a general state of recession since the mid to late 1700's. The prominent lateral moraines formed prior to 1882 AD. Four low moraines located within the Coe Glacier trough formed before 1901. Historical records indicate that the Coe Glacier has generally continued to recede since then.
A comparison of the moraine ages and the historical activity of the Coe Glacier to other glaciers on Mount Hood as well as others in the Pacific Northwest and Scandinavia reveals that fluctuations of the glacier termini are generally synchronous. This similarity, combined with the similarity of the ages of Coe Glacier moraines to cool periods in a long term temperature record, indicates that hemispheric climatic patterns have played a major role in the past fluctuations of the Coe Glacier.
| Identifer | oai:union.ndltd.org:pdx.edu/oai:pdxscholar.library.pdx.edu:open_access_etds-4807 |
| Date | 01 January 1988 |
| Creators | Lillquist, Karl Douglas |
| Publisher | PDXScholar |
| Source Sets | Portland State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Dissertations and Theses |
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