Recent studies using computer modeling to investigate how melting ice in Antarctica affects the world’s oceans have largely focused on aspects such as Icy layer geometry, fracture and surface melting, which can lead to or accelerate the loss of ice sheet mass. Now, a research team of Stanford University Identify and describe an additional process that could have a similarly powerful effect on the future of the Antarctic ice sheets: the melting of the ice sheet at the interface of the Earth and the ice sheets miles thick above it—a phenomenon known as basal melt.
Using numerical models of the ice sheets, the researchers tested whether the onset of basal melt could lead to a significant loss of ice over a 100-year period, and discovered that the melt release could lead to mass loss in areas of the ice sheet that normally wouldn’t. Associated contributions to instability and sea-level rise are on such a short time scale.
He said, “There hasn’t been a lot of continent-wide work, or no work at all, looking at the onset of thawing—that transition from frozen ice to ice at melting point, where a little water at the bottom can cause the ice to slide.” “. Study lead author Elisa Dawson, a PhD student in geophysics at Stanford University. “We were interested in knowing how big the impact the thaw could have and what areas of the ice sheet are likely to be most vulnerable.”
Dawson and her colleagues modeled temperature changes at the base of Antarctica according to shifts in friction caused by the ice sheet sliding over the land beneath. The simulations revealed that in East Antarctica – an area considered relatively stable compared to West Antarctica – the Enderby Kemp and George V Land regions would be most sensitive to basal melt. If melting occurs, such areas could end up being a major contributor to sea level rise, compared to the rapidly developing and unstable Thwaites Glacier in West Antarctica.
“The whole community is really focused on Thwaites right now,” said Dustin Schroeder, senior author of the study, an associate professor of geophysics and electrical engineering at Stanford University. “But some of the areas that are the usual suspects of significant and impactful changes are not the most provocative and influential areas in this study.”
Although scientists do not yet know what forces are most capable of triggering basal melt in the potentially vulnerable areas identified in this study, one potential driver could be changing ocean conditions. Professor Schroeder explained: “The warm ocean waters don’t necessarily reach these areas of East Antarctica as they do in parts of West Antarctica, but they are close, so there is a possibility that could change.” “When you think about recent theoretical work showing that thermal processes in the bed can be easily activated — even spontaneous — it makes the near-term thaw seem like a much easier switch than we thought.”
“Continued work will be needed to take a closer look at these areas identified in this paper. Proving that bed melting can lead to mass loss from the ice sheet, Dawson concluded, is a process that society needs to understand and really start looking at — especially in these potentially vulnerable areas.”
The study was published in the journal Nature Connections.
by Andrei IonescuAnd the Earth.com crew clerk