Glaciers in the colder climates of our planet have been helping the mountains grow taller, according to new research which contradicts previously held theories regarding the effect glaciers had on mountains.
Before this study, scientists thought that any interaction between a mountain and a glacier resulted in what was dubbed the “glacial buzz saw” – wherein the perpetually frozen glaciers slide down the mountain face and carve away its surface as it goes.
This theory has led scientists to believe that glaciers limit the height of the mountains, but in the cold Patagonian Andes scientists from the University of Arizona and Yale University have found just the opposite in action.
“Climate, especially through glaciers, has a really big impact on how big mountains get,” said Reiners, a UA professor of geosciences.
“What we’re seeing is that below certain latitudes, glacial buzzsaws clearly and efficiently operate, but south of about 45 degrees, it not only doesn’t work – it has the opposite effect,” he said. “The glaciers actually protect the surface and allow the mountains to grow higher.”
In cold climates such as the Patagonian Andes, rather than scraping away the surface of the mountain as was previously thought to happen, the glaciers protect the mountain top and sides from erosion, leading the team to dub the action as “glacial armouring.”
Reiners and his colleagues also believe that this action will also take place on mountains in the far north such as in Alaska.
“What corroborates this is that the mountains are higher in the south than in the north,” said Reiners. “Uplift is winning in the south, and the glacial buzzsaw is winning in the north.”