Glacial cirques and the relationship between equilibrium line altitudes and mountain range height

Abstract

Research Article| January 01, 2015 Glacial cirques and the relationship between equilibrium line altitudes and mountain range height Sara Gran Mitchell; Sara Gran Mitchell 1Department of Biology, College of the Holy Cross, P.O. Box B, 1 College Street, Worcester, Massachusetts 01610, USA Search for other works by this author on: GSW Google Scholar Elizabeth E. Humphries Elizabeth E. Humphries 2Department of Geological Sciences, University of North Carolina–Chapel Hill, 104 South Road, Campus Box #3315, Chapel Hill, North Carolina 27599, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Sara Gran Mitchell 1Department of Biology, College of the Holy Cross, P.O. Box B, 1 College Street, Worcester, Massachusetts 01610, USA Elizabeth E. Humphries 2Department of Geological Sciences, University of North Carolina–Chapel Hill, 104 South Road, Campus Box #3315, Chapel Hill, North Carolina 27599, USA Publisher: Geological Society of America Received: 13 Aug 2014 Revision Received: 16 Oct 2014 Accepted: 19 Oct 2014 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2014 Geological Society of America Geology (2015) 43 (1): 35–38. https://doi.org/10.1130/G36180.1 Article history Received: 13 Aug 2014 Revision Received: 16 Oct 2014 Accepted: 19 Oct 2014 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Sara Gran Mitchell, Elizabeth E. Humphries; Glacial cirques and the relationship between equilibrium line altitudes and mountain range height. Geology 2015;; 43 (1): 35–38. doi: https://doi.org/10.1130/G36180.1 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 SocietyGeology Search Advanced Search Abstract A global GIS- and literature-based analysis of the altitude and relief of more than 14,000 ice-free glacial cirques in 56 study areas ranging from 69°N to 77°S shows that average cirque floor altitudes vary with latitude in a zone centered on the Quaternary average equilibrium line altitude (QA-ELA). In addition, relief above cirque floors averages 346 ± 107 m, and is rarely >600 m. In regions where ice-free cirques are abundant, cirque relief is independent of modern precipitation rates, tectonic regime, and relative peak height, limiting peaks to within a fixed distance above the QA-ELA and thus causing them to also parallel the ELA. We propose a physical process model where, under suitable geologic and tectonic conditions, climate exerts a first-order control on mountain range height. In this model, glacial erosion excavates a zone of cirques with floors centered on the QA-ELA, while climate-driven weathering processes on adjacent slopes limit the peaks to within a few hundred meters above this zone. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.