Thawing rate of glaciers depends on climate as well as on their shape, scientists say

ST. PETERSBURG, October 16. /TASS/. Scientists of the Arctic and Antarctic Research Institute (AARI, St. Petersburg) found that the rate of glacier melting depends not only on climatic factors, but also on the ice mass' shape, the institute's press service said.

"The rate of glaciers' melting depends not only on climate warming, but also on the glaciers' shape and size," the press service said. "Without adjusting assessments to the "geometry" factor, the climate estimates, based on temperature changes data, risk being inaccurate."

The scientists came to this conclusion based on results of years-long glaciological monitoring of two mountain-valley glaciers - the Aldegonda and the West Grenfjord - on the Spitsbergen Archipelago. Between 2013 and 2025, the glaciers lost about 18-20 meters of water equivalent mass, they said.

The scientists used two ways to calculate the mass balance - based on the annual changes in the glacier's surface shape, and based on the geometry relative to that recorded in 2008. The specialists found that as a result of the glaciers' shifting to lower, warmer altitude zones, they are losing annually additional 1-2% of ice on the Aldegonde and 0.5-1% on the Western Grenfjord in addition to what may be attributed to the climate. According to the scientists, over recent two decades, this addition is still not big and does not distort the overall climate assessment. However, the longer the series of observations, and the faster the glacier is melting, the more noticeable this "addition" becomes.

"The glacier is a living, constantly changing object," the institute's senior researcher Anton Terekhov explained. "As it is melting, its surface is sinking lower and lower, and down there, the air is warmer - and as a result, the ice starts melting even faster, even if the weather has not changed by a single degree. Right now, this effect is not big, but if it is not taken into account when analyzing longer series of observations, we risk mistaking part of that "geometric" history of a glacier for a climate signal that does not actually exist."

The institute's experts suggest applying this research method to other glaciers in the world. They are confident that thanks to satellite digital terrain models covering the entire Arctic and Antarctic, such calculations could be made for almost any glaciation center.

"This way we will be able to separate more accurately the real consequences of global warming from the "internal processes" of the glaciers and, accordingly, to predict more accurately their future," the press service said in conclusion.