Water temperatures at a Florida-size glacier in Antarctica alarm scientists
in Antarctica have recorded, for the first time, unusually warm water beneath a glacier that is the size of Florida and is already melting and contributing to a rise in sea levels.
The researchers, working on the Thwaites Glacier, recorded water temperatures at the base of the ice of more than 2 degrees Celsius, or 3.6 degrees Fahrenheit, above the normal freezing point. Critically, the measurements were taken at the glacier’s grounding line, the area where it transitions from resting wholly on bedrock to spreading out on the sea as ice shelves.
It is unclear how fast the glacier is deteriorating: Studies have forecast its total collapse in a century and also in a few decades. The presence of warm water in the grounding line might support estimates at the faster range.
That is significant because the Thwaites, along with the Pine Island Glacier and a number of smaller glaciers, acts as a brake on part of the much larger
West Antarctic Ice Sheet. Together, the two bigger glaciers are currently holding back ice that, if melted, would raise the world’s oceans by about four feet over centuries, an amount that would put many coastal cities underwater.
“Warm waters in this part of the world, as remote as they may seem, should serve as a warning to all of us about the potential dire changes to the planet brought about by climate change,” said David Holland, a lead researcher on the expedition and director of New York University’s Environmental Fluid Dynamics Laboratory.
Glaciologists have previously raised alarm over the presence of warm water melting the Thwaites from below. This is the first time, though, that warm waters have been measured at the
The Thwaites Glacier helps to keep the much larger West Antarctic Ice Shelf stable. Scientists have recorded, for the first time, unusually warm water beneath the glacier. glacier’s grounding line.
To observe activity beneath the glacier, Holland’s team drilled a hole from the surface to the bottom and then deployed equipment that measures water temperature and ocean turbulence, or the mixing of freshwater from the glacier and salty ocean water. Warm waters beneath the Thwaites are actively melting it, the team found.
Drilling the hole — roughly one foot wide and 1,970 feet deep — and collecting the data took about 96 hours in subzero weather. The results of the study are expected to be published in March. The expedition was part of the International Thwaites Glacier CollabScientists oration, a series of research projects aimed at understanding the glacier.
“It certainly has a big impact on our U.S. coast and in many areas,” said Twila Moon, a researcher with the National Snow and Ice Data Center at the University of Colorado Boulder. Moon was not part of the expedition.
While scientists might not yet be able to definitively predict how soon glaciers like the Thwaites will melt, human-caused climate change is a key factor. The biggest predictor of “how much ice we will lose and how quickly we will lose it,” Moon said,”is human action.”