At a Monday talk, Dr. Jonathan Kingslake explained the basics of how glaciers flow.
One of the many interesting things about ice is that it is a viscoelastic solid. The bonds between ice can compress, the elastic component, allowing us to stand on it and to behave like a solid. But these bonds can also break, allowing ice to deform and flow. On Monday’s Ice Flows: Using Math and Physics to Understand How event, Dr. Jonathan Kingslake, an assistant professor in the Earth and Environmental Studies Department, explained some of the basic principles behind why ice flows and why it’s important.
Ice flow is critical in understanding glaciers, which are accumulations of snow and ice so large that they flow under their own weight. Glaciers form over the course of years—as snow builds up, the weight of years of snow compacts it into ice, and eventually, there is enough snow and ice that it begins to flow under its own weight. The driving force behind this flow is gravity: glaciers flow downhill.
While this may seem like an insignificant fact, it’s critical to have liquid water on the planet. Were glaciers to not flow, snow and ice would pile up higher and higher in cold zones but never flow to reach an ablation zone, the region where melting occurs. If this were the case, nothing would stop huge amounts of water from simply being locked up in snow and ice. But because glaciers flow from an accumulation zone to the ablation zone, glaciers also lose mass as the ice melts to water, returning water to the earth system. Dr. Kingslake described it as a kind of “conveyor belt” that cycles water between the atmosphere and the cryosphere and the oceans.
Understanding ice flow is also critically important in understanding the impacts of climate change. Glaciers are globally in retreat, with a few dwindling exceptions. Therefore, understanding their movement can help us understand how much mass they are losing, a critical component in understanding both how much and how fast sea levels will rise.
Glacier Perito Moreno via Wikimedia Commons