The “glacier of the apocalypse” is melting from below and it’s not good news – Ouest-France evening edition

The “glacier of the apocalypse” is melting from below and it’s not good news – Ouest-France evening edition
The “glacier of the apocalypse” is melting from below and it’s not good news – Ouest-France evening edition

Strategically located, Antarctica’s Thwaites Glacier is preventing a huge amount of ice from melting at high speed. But it is shrinking under global warming and a new study shows it is also losing ground due to groundwater infiltration.

It is known by the unflattering nickname of “glacier of the apocalypse”, as its role is central in the phenomenon of melting ice and rising ocean levels. For geography, it is the Thwaites Glacier, located to the west of the southern continent.

This white giant, 120 kilometers wide and 192,760 km2 surface area, loses around 50 billion tonnes of ice each year. Between 1992 and 2011, the line between solid and liquid water receded at the rate of one kilometer per year. An evolution linked to global warming which started in the 1940s. “It contains enough ice to raise sea levels by 65 cm. It is therefore THE major glacier in West Antarctica, and which shows very worrying signs of instability”underlines Romain Millan, glaciologist at the Institute of Geosciences and the Environment (IGE), interviewed by the evening edition. Especially since its strategic position also makes it possible to stabilize the entire region. “The issues surrounding the evolution of this glacier are extremely important. If it is destabilized, it can destabilize the entire basin it drains”explained glaciologist Lydie Lescarmontier, at the microphone of France Culturein March 2024, comparing the site to a cork that prevents ice from leaving the oceans.

Read also: The dramatic melting of the largest French glacier

Seawater intrusions

Until now, the scientific community thought that melting only took place at the boundary between water and ice, but examination of the ice cores taken could not explain the speed of the process. A study, published in April 2024 in the scientific journal Pnasshows, thanks to satellite images, that the loss also occurs at depth.

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It is the tides that bring salt water up to 6 km inland, under the ice. “This new study provides truly unique observations. For the first time, from space, we can measure over a vast region, several times a day, the rise and descent of the floating platform attached to the Thwaites glacier, comments Romain Millan. This provides data that scientists have never had before on warm water intrusions beneath the glacier. These observations are consistent with the course of the tides which will facilitate these intrusions of warm water and therefore significantly increase melting. »

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A big step towards understanding the phenomenon

These new lessons should make it possible to better predict the retreat of the glacier and therefore the rising water levels which threaten the coastlines. “The study sheds light on a unique phenomenon, which is not yet taken into account in scientists’ numerical models, and therefore in the projections we make of sea level. Studying it better and finding ways to represent it correctly in models will allow us to better understand the future evolution of sea levels”estimates the IGE glaciologist, specialized in the dynamics of glaciers and polar ice sheets.

Read also: This country wants to save its glacier by covering it with plastic, experts denounce an “absurd” project

In terms of solutions, the future of the “glacier of the apocalypse” depends on humanity’s ability to drastically reduce its greenhouse gas emissions, in order to limit global warming as much as possible. To keep it below 2°C, or even 1.5°C, it will be necessary to achieve carbon neutrality in 2050.

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