The Doomsday Glacier Is Getting Closer and Closer to Irreversible Collapse
4 months ago
- #Climate Change
- #Antarctica
- #Thwaites Glacier
- The Thwaites Glacier, known as the 'Doomsday Glacier,' is rapidly changing and poses significant uncertainty for global sea level rise predictions.
- Cracks in the eastern ice shelf have increased over the past two decades, weakening its structural stability.
- A study by the International Thwaites Glacier Collaboration (ITGC) details the gradual collapse process, tracking crack formation and propagation from 2002 to 2022.
- The weakening of the ice shelf occurred in four phases, with crack growth in two stages: long cracks along the ice flow and short cross-flow cracks.
- Satellite images show the total length of cracks increased from 165 km in 2002 to 336 km in 2021, with a notable increase in small cracks.
- A feedback loop exists where cracks accelerate ice flow, and increased speed generates new cracks, as recorded by GPS devices between 2020 and 2022.
- Structural changes in the shear zone advanced at approximately 55 km per year during the winter of 2020, impacting upstream ice flow.
- The state of tension in the ice shelf has shifted over time, reflecting loss of connection to the anchorage point.
- The deterioration patterns observed could apply to other ice shelves, such as the Wadi Ice Shelf in the western Antarctic Peninsula.
- The Thwaites Glacier's reverse-slope bed makes retreat likely to progress toward irreversible collapse, potentially raising sea levels by about 65 cm.
- Numerical models estimate the ice sheet and shelf will retreat at nearly 1 km per year over the next 40 years.
- The study provides key data for validating numerical collapse models and understanding the future of Antarctic ice shelves.