Magnitudes and implications of peak discharges from glacial Lake Missoula

Abstract

Research Article| March 01, 1992 Magnitudes and implications of peak discharges from glacial Lake Missoula JIM E. O'CONNOR; JIM E. O'CONNOR 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar VICTOR R. BAKER VICTOR R. BAKER 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Author and Article Information JIM E. O'CONNOR 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 VICTOR R. BAKER 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1992) 104 (3): 267–279. https://doi.org/10.1130/0016-7606(1992)104<0267:MAIOPD>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation JIM E. O'CONNOR, VICTOR R. BAKER; Magnitudes and implications of peak discharges from glacial Lake Missoula. GSA Bulletin 1992;; 104 (3): 267–279. doi: https://doi.org/10.1130/0016-7606(1992)104<0267:MAIOPD>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search 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 ± 3 million m3̇ sec-1. Downstream at Wallula Gap, a major point of flow convergence, peak discharge was about 10 ± 2.5 million m3̇sec-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 jökulhlaup-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. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.