Glacial and periglacial buzzsaws: fitting mechanisms to metaphors
2014 (English)In: Quaternary Research, ISSN 0033-5894, E-ISSN 1096-0287, Vol. 81, no 2, 189-192 p.Article in journal (Refereed) Published
The buzzsaw hypothesis refers to the potential for glacial and periglacial processes to rapidly denude mountains at and above glacier Equilibrium Line Altitudes (ELAs), irrespective of uplift rates, rock type or pre-existing topography. Here the appropriateness of the buzzsaw metaphor is examined alongside questions of the links between glacial erosion and ELAs, and whether the glacial system can produce low-relief surfaces or limit summit heights. Plateau fragments in mountains on both active orogens and passive margins that have been cited as products of glacial and periglacial buzzsaw erosion instead generally represent dissected remnants of largely inherited, pre-glacial relief. Summit heights may correlate with ELAs but no causal link need be implied as summit erosion rates are low, cirque headwalls may not directly abut summits and, on passive margins, cirques are cut into pre-existing mountain topography. Any simple links between ELAs and glacial erosion break down on passive margins due to topographic forcing of ice-sheet growth, and to the km-scale vertical swaths through which ELAs have shifted through the Quaternary. Glaciers destroy rather than create low-relief rock surfaces through the innate tendency for ice flow to be faster, thicker and warmer along valleys. The glacial buzzsaw cuts down.
Place, publisher, year, edition, pages
2014. Vol. 81, no 2, 189-192 p.
Buzzsaw, Tectonics, Glaciers, Mountains, Erosion
IdentifiersURN: urn:nbn:se:su:diva-119791DOI: 10.1016/j.yqres.2013.10.007ISI: 000334154300002OAI: oai:DiVA.org:su-119791DiVA: diva2:848368