The “glacier at the end of the world “, Thwaites located in West Antarctica does not receive this nickname by chance: it has the potential to devastate the world . This glacier is roughly the size of Great Britain and, according to NASA estimates, if it melted it would raise sea levels considerably. But this fact by itself is not the most worrying thing. The problem is what would trigger this cascade of melting ice. As an example, the glaciers currently protected from the warming of the ocean thanks to the backing of this enormous glacier would be exposed, which would cause a rise in sea level that would end up submerging important cities such as New York or Miami and even the Netherlands.
If we were already aware that it was receding at an alarming rate, a recent study published in the journal Proceedings of the National Academy of Sciences fears that this rate could accelerate even more after discovering that the increase in damage weakens the integrity of the ice shelf, so they are starting to crack more and more.
In initial phase of disintegration
The glacier is melting at an alarming rate: about 0.8 kilometers per year. Scientists estimate that the glacier will lose all of its ice in about 200 to 600 years. When it does, it will raise the sea level by 0.5-0.6 meters.
Researchers analyzed satellite images taken between 1997 and 2019 to document increasing damage to ice shelves . The goal was to identify how the increasing damage to the ice shelf was affecting its strength by monitoring the cracked and fragmented sections from the edge of the glacier. The research focused on the rapid development of the damaged areas of the Pine Island and Thwaites ice shelves, where the glacier meets the ocean. The images leave no room for doubt: they show cracks and fissures in the glaciers.
The model revealed that as the ice shelf becomes more damaged, it initiates a feedback process that further weakens the ice shelf, accelerating the development of areas of thinning and cracks that result in ice section ruptures. This finding demonstrates the importance of considering these feedback processes in order to make predictions of sea level rise and evaluate the stability of the remaining ice shelves.
The keys to this discovery
The researchers believe that the damage observed in the ice shelves will generate even more fractures, because:
- Undermines the structural integrity of ice shelves.
- It weakens ice shelves and makes them more vulnerable to warming air and ocean temperatures.
- It creates a feedback loop, leading to further weakening and further detriment to the structure.
Recall that sea levels are currently increasing by around 3.5 millimeters per year, and the Thwaites glacier represents between 4 and 5% of the total, so the importance of this glacier goes far beyond its own survival. The release of the ice masses turned into water could devastate coastal settlements around the world.
If the entire Antarctic ice sheet melted, scientists estimate that the sea level would rise by about 60 meters.
Referencia: Damage accelerates ice shelf instability and mass loss in Amundsen Sea Embayment. Stef Lhermitte, Sainan Sun, Christopher Shuman, Bert Wouters, Frank Pattyn, Jan Wuite, Etienne Berthier, and Thomas Nagler. PNAS first published September, 2020 https://doi.org/10.1073/pnas.1912890117
