Further proof that glaciers are not well understood


Glacial armoring

A new paper in Nature shows that glaciers can both help mountains grow as well as cause erosion. The stubborn certainty displayed by Pachauri and the IPCC about glaciers seems all the more ridiculous.

Stuart N. Thomson, Mark T. Brandon, Jonathan H. Tomkin, Peter W. Reiners, Cristián Vásquez, Nathaniel J. Wilson.Glaciation as a destructive and constructive control on mountain buildingNature, 2010; 467 (7313): 313 DOI:10.1038/nature09365

Glaciers can help actively growing mountains become higher by protecting them from erosion, according to a University of Arizona-led research team. The finding is contrary to the conventional view of glaciers as powerful agents of erosion that carve deep fjords and move massive amounts of sediment down mountains. Mountains grow when movements of the Earth’s crust push the rocks up. The research is the first to show that the erosion effect of glaciers — what has been dubbed the “glacial buzzsaw” — reverses on mountains in colder climates.

Glaciers atop mountains in temperate latitudes flow downhill, scouring away the surface of the mountain. Over millennia, such erosion can reduce the height and width of a mountain range by miles. However in very cold climates such as the Patagonian Andes, rather than scraping away the surface of the mountain, the team found that glaciers protect the mountain top and sides from erosion. The team dubs the action of the cold-climate glaciers “glacial armoring.”

“Climate, especially through glaciers, has a really big impact on how big mountains get,” said Reiners, a UA professor of geosciences.

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