A catastrophic flood caused by drainage of a caldera lake at Aniakchak Volcano, Alaska, and implications for volcanic hazards assessment

Abstract

Research Article| July 01, 1996 A catastrophic flood caused by drainage of a caldera lake at Aniakchak Volcano, Alaska, and implications for volcanic hazards assessment Christopher F. Waythomas; Christopher F. Waythomas 1U.S. Geological Survey, Alaska Volcano Observatory, 4200 University Drive, Anchorage, Alaska 99508 Search for other works by this author on: GSW Google Scholar Joseph S. Walder; Joseph S. Walder 2U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Search for other works by this author on: GSW Google Scholar Robert G. McGimsey; Robert G. McGimsey 1U.S. Geological Survey, Alaska Volcano Observatory, 4200 University Drive, Anchorage, Alaska 99508 Search for other works by this author on: GSW Google Scholar Christina A. Neal Christina A. Neal 1U.S. Geological Survey, Alaska Volcano Observatory, 4200 University Drive, Anchorage, Alaska 99508 Search for other works by this author on: GSW Google Scholar Author and Article Information Christopher F. Waythomas 1U.S. Geological Survey, Alaska Volcano Observatory, 4200 University Drive, Anchorage, Alaska 99508 Joseph S. Walder 2U.S. Geological Survey, Cascades Volcano Observatory, 5400 MacArthur Boulevard, Vancouver, Washington 98661 Robert G. McGimsey 1U.S. Geological Survey, Alaska Volcano Observatory, 4200 University Drive, Anchorage, Alaska 99508 Christina A. Neal 1U.S. Geological Survey, Alaska Volcano Observatory, 4200 University Drive, Anchorage, Alaska 99508 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1996) 108 (7): 861–871. https://doi.org/10.1130/0016-7606(1996)108<0861:ACFCBD>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Christopher F. Waythomas, Joseph S. Walder, Robert G. McGimsey, Christina A. Neal; A catastrophic flood caused by drainage of a caldera lake at Aniakchak Volcano, Alaska, and implications for volcanic hazards assessment. GSA Bulletin 1996;; 108 (7): 861–871. doi: https://doi.org/10.1130/0016-7606(1996)108<0861:ACFCBD>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 Aniakchak caldera, located on the Alaska Peninsula of southwest Alaska, formerly contained a large lake (estimated volume 3.7 × 109 m3) that rapidly drained as a result of failure of the caldera rim sometime after ca. 3400 yr B.P. The peak discharge of the resulting flood was estimated using three methods: (1) flow-competence equations, (2) step-backwater modeling, and (3) a dam-break model. The results of the dam-break model indicate that the peak discharge at the breach in the caldera rim was at least 7.7 × 104 m3 s−1, and the maximum possible discharge was ≈1.1 × 106 m3 s−1. Flow-competence estimates of discharge, based on the largest boulders transported by the flood, indicate that the peak discharge values, which were a few kilometers downstream of the breach, ranged from 6.4 × 105 to 4.8 × 106 m3 s−1. Similar but less variable results were obtained by step-backwater modeling. Finally, discharge estimates based on regression equations relating peak discharge to the volume and depth of the impounded water, although limited by constraining assumptions, provide results within the range of values determined by the other methods. The discovery and documentation of a flood, caused by the failure of the caldera rim at Aniakchak caldera, underscore the significance and associated hydrologic hazards of potential large floods at other lake-filled calderas. 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.