Potential effects of volcanic warming on ice-sheet melting and sea level rise still to be determined
Tracing a chemical signature of helium in seawater, an international team of scientists funded by the National Science Foundation (NSF) and the United Kingdom’s (U.K.) Natural Environment Research Council (NERC) has discovered a previously unknown volcanic hotspot beneath the massive West Antarctic Ice Sheet (WAIS).
Researchers say the newly discovered heat source could contribute in ways yet unknown to the potential collapse of the ice sheet.
The scientific consensus is that the rapidly melting Pine Island Glacier, the focal point of the study, would be a significant source of global sea level rise should the melting there continue or accelerate. Glaciers such as Pine Island act as plugs that regulate the speed at which the ice sheet flows into the sea.
The new research was published by an international team, led by Brice Loose of the Graduate School of Oceanography at the University of Rhode Island. His research was supported by an award from NSF’s Office of Polar Programs, which manages the U.S. Antarctic Program.
Researchers from East Anglia and Southampton universities in the U.K., Arizona State University, the Woods Hole Oceanographic Institution, and the British Antarctic Survey contributed to the study.
Their findings were published in the June 22 edition of the journal Nature Communications.
Peter Milne, program director for ocean and atmospheric science in NSF’s Division of Polar Programs, noted that the discovery adds significant information about what controls the stability of the Antarctic ice sheets.
“To model the complex processes of how the ice sheets move is a difficult, but essential thing to do if we are to understand their role in the global climate and their potential for contributing to sea level rise,” he said. “This research may add a critical piece of information as we try to assemble that ‘big picture.'”
The researchers first noted the volcanic activity in 2007 and verified its existence again in 2014.
It remains unclear how the newly discovered activity affects knowledge about the glacier, because researchers don’t yet know how volcanic heat is distributed along the bottom of the ice sheet. However, researchers do know that the heat from the volcano is producing melting beneath the ice sheet. This meltwater is leaking across the grounding line where the ice shelf meets the ocean.
The heat source, Loose and team note, is about half that of the active volcano Grímsvötn, in Iceland.