Cold Cuts: Glaciers Sculpt Steep Peaks

Description

A new global analysis of peaks suggests that rather than limiting mountain height at high latitudes and altitudes, glaciers may make these peaks pointier and taller. By carving out U-shaped valleys, glaciers lighten the load of the mountain range, allowing the scraped-out piece of crust to float higher on Earth’s fluid mantle, like an unloaded boat.

“If you have very steep peaks and large, deep valleys, the load of the mountain range above the sea level is quite low,” said Jörg Robl, a geodynamics modeler at the University of Salzburg in Austria, “so even a thinner crust is sufficient to support very high peaks.”

Subject

In environments raked by glaciers, tall peaks like Denali still survive, held up by surprisingly thin crust.