Doomsday Glacier: Satellite Data Shows Dangerous Cracks - Scientists Warn of Rising Seas

Satellites have shown quick changes in the “Doomsday Glacier,” known as the Thwaites Glacier in West Antarctica. This glacier is one of the most rapidly changing in the world, and scientists are closely watching it because what happens in the coming years could greatly affect how much sea levels rise.
A key part of this glacier system is the Thwaites Eastern Ice Shelf (TEIS), which is a large floating mass of ice. At its northern end, the shelf is partly held in place by a small area of land, called a pinning point. In the last twenty years, cracks have been spreading across the shelf, especially near a major area where the ice moves differently, known as a shear zone, just upstream of the pinning point.
A new study, published in the Journal of Geophysical Research: Earth Surface, gives the most detailed view so far of how this slow breakdown has happened.
The team used twenty years of satellite images, measurements of how fast the ice is moving, and GPS data collected directly on the glacier. Their findings show that as these cracks grew, the shelf’s connection to the pinning point became weaker. Once the shelf started to separate from the pinning point, the ice behind it began to move faster, making the whole structure even more unstable.
The researchers found four clear stages in this breakdown. They also made two important discoveries. First, the cracking happened in two steps: long cracks that followed the direction of the glacier’s movement appeared first; later, shorter cracks developed that cut across that direction.
Second, they found strong evidence of a feedback process. As the cracks weakened the shelf, the ice sped up, and this extra movement caused even more damage. This cycle of speeding ice and worsening cracks played a big role in the shelf’s recent breakdown.
One of the most surprising findings is how the pinning point has changed its role. For many years, it helped to keep the floating shelf stable. Now, however, it seems to be making the shelf weaker, as the changing shape of the ice makes the connection more fragile.
Researchers think that this four-stage pattern of decline might happen in other Antarctic ice shelves that are showing signs of similar stress. If these floating shelves keep getting thinner, Antarctica’s contribution to sea-level rise could increase more quickly in the future.