Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Magnitudes and implications of peak discharges from glacial Lake Missoula

Jim E. O'Connor and Victor R. Baker
Magnitudes and implications of peak discharges from glacial Lake Missoula
Geological Society of America Bulletin (March 1992) 104 (3): 267-279

Abstract

New field evidence and discharge calculation procedures provide new estimates of maximum late Pleistocene glacial Lake Missoula flood discharges for two important reaches along the flood route. Within the Spokane Valley, near the point of release, the peak discharge probably exceeded 17 + or - 3 million m (super 3) . sec (super -1) . Downstream at Wallula Gap, a major point of flow convergence, peak discharge was about 10 + or - 2.5 million m (super 3) .sec (super -1) . Flow duration was on the order of several days. These are the largest known terrestrial fresh-water flows.Consideration of these discharge values constrains models for the failure of glacial Lake Missoula. The maximum discharges estimated here are larger than theoretical and empirical predictions of maximum subglacial joekulhlaup-style releases for Lake Missoula. We postulate, consistent with geological relations in the glacial Lake Missoula basin and in the Channeled Scabland, that the largest late Wisconsinan Missoula Flood resulted from a cataclysmic failure of the impounding ice dam of glacial Lake Missoula. This large release may have been the result of a complete rupture of the ice dam. Subsequent multiple flows of lesser magnitude may have resulted from repeated subglacial releases from the lake.


ISSN: 0016-7606
EISSN: 1943-2674
Coden: BUGMAF
Serial Title: Geological Society of America Bulletin
Serial Volume: 104
Serial Issue: 3
Title: Magnitudes and implications of peak discharges from glacial Lake Missoula
Affiliation: Univ. Ariz., Dep. Geosci., Tucson, AZ, United States
Pages: 267-279
Published: 199203
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 50
Accession Number: 1992-008056
Categories: Quaternary geology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 3 tables, sketch maps
N42°00'00" - N49°00'00", W117°15'00" - W111°04'60"
N44°30'00" - N49°00'00", W116°01'60" - W104°01'60"
N45°30'00" - N49°00'00", W124°45'00" - W116°55'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute.
Update Code: 1992
Close Modal

or Create an Account

Close Modal
Close Modal