3D radar scan provides clues about threats to iconic Alaskan glacier
A detailed "body scan" of Malaspina Glacier, one of Alaska's most iconic glaciers, revealed that its bulk lies below sea level and is undercut by channels that may allow ocean water to gain access, should its coastal barrier ...
The findings, published by University of Arizona researchers in the Journal of Geophysical Research, underscore the fragility of a very large glacial system that could lead to the loss of a significant volume of ice and National Park Service land and would contribute a measurable volume to global sea level rise.
"The loss of this glacier would likely be the largest loss of ice from an Alaskan glacier within this century," said lead study author Brandon Tober, a doctoral student in the UArizona Department of Geosciences.
The area in front of Malaspina Glacier, a permafrost zone with pure ice beneath the surface, is "wasting away" in the face of rising global temperatures, Tober said. Permafrost refers to ground that remains frozen for two or more years.
"As this coastal barrier erodes and gives way to large lagoons, primarily through the collapse of ice cliffs, ocean water may eventually gain access to the glacier," Tober said. "Once it gets to the front of the glacier, it may melt the ice even faster and initiate the glacier's retreat."
Located in southeast Alaska, Malaspina Glacier spills out from the St. Elias Mountains onto the coastal plain as a "pancake of ice". New research revealed certain features make the glacier particularly vulnerable to melting. Credit: Brandon Tober
Vegetation growing atop massive ground ice – a crevassed forest – is seen in this aerial photo of the land strip that separates Malaspina Glacier from the Pacific Ocean. This coastal barrier "wastes away," the researchers say, as ice cliffs collapse and form a growing expanse of lagoons. Credit: Brandon Tober/University of Arizona
Donning flight suits, Jack Holt (left) and Brandon Tober await a helicopter ride back to base camp after completing a geophysical survey on Malaspina Glacier. Credit: Jack Holt/University of Arizona