Scientists find missing piece in glacier melt predictions

https://www.sciencedaily.com/releases/2018/10/181015100508.htm

Stanford scientists have revealed the presence of water stored within a glacier in Greenland, where the rapidly changing ice sheet is a major contributor to the sea-level rise North America will experience in the next 100 years. This observation -- which came out of a new way of looking at existing data -- has been a missing component for models aiming to predict how melting glaciers will impact the planet.

The group made the discovery looking at data intended to reveal the changing shape of Store Glacier in West Greenland. But graduate student Alexander Kendrick figured out that the same data could measure something much more difficult to observe: its capacity to store water. The resulting study, published in Geophysical Research Letters, presents evidence of glacier meltwater from the surface being stored within damaged, solid ice. While ice melting at the surface has been well documented, little is known about what happens below glacier surfaces, and this observation of liquid water stored within solid ice may explain the complex flow behavior of some Greenland glaciers.

"Things like this don't always come along, but when they do, that is the real 'joy of the discovery' component of Earth science," said co-author Dustin Schroeder, an assistant professor of geophysics at Stanford University's School of Earth, Energy & Environmental Sciences (Stanford Earth). "This paper not only highlights this component's existence, but gives you a way to observe it in time."

Surface meltwater plays an important role in Greenland by lubricating the bottoms of ice sheets and impacting how retreating glaciers are affected by the ocean. The process of how the glaciers melt and where the water flows contributes to their behavior in a changing climate, as these factors could alter glaciers' response to melting or impact the timeline for sea-level rise. Knowing that some liquid is intercepted within glaciers after melting on the surface may help scientists more accurately predict oceanic changes and help people prepare for the future, Schroeder said.