Microscopic defects allow glacier movement to be predicted

May 31. () –

The flow of a glacier depends largely on how microscopic defects move through the ice, a new study has revealed. MIT (Massachusetts Institute of Technology).

As they seep and break off into the sea, melting glaciers and ice sheets are raising global water levels at an unprecedented rate. To predict and prepare for future sea level rise, scientists need a better understanding of how quickly glaciers melt and what influences their flow.

The new study has revealed that a glacier’s flow can be estimated based on whether the ice is prone to microscopic defects of one type or another. The authors used this relationship between micro- and macro-scale deformation to develop a new model of how glaciers flow. Using the new model, they mapped ice flow in places along the Antarctic ice sheet.

Contrary to conventional belief, they found that the ice sheet is not a monolith, but rather is more varied in where and how it flows in response to stresses driven by warming. The study “drastically alters the climatic conditions under which sea ice sheets can become unstable and drive rapid rates of sea level rise,” the researchers write in their paper.

“This study really shows the effect of microscale processes on macroscale behavior,” says it’s a statement Meghana Ranganathan, who led the study as a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS) and is now a postdoc at Georgia Tech. “These mechanisms occur at the scale of water molecules and, “Ultimately, they may affect the stability of the West Antarctic Ice Sheet.”

“Generally speaking, glaciers are accelerating and there are a lot of variants around that,” adds co-author and EAPS associate professor Brent Minchew. “This is the first study to take a step from the laboratory to the ice sheets and begin to evaluate what the ice stability in the natural environment. “That will ultimately fuel our understanding of the likelihood of catastrophic sea level rise.”

Ranganathan and Minchew’s study appears this week in Proceedings of the National Academy of Sciences (PNAS).