Thwaites Glacier
Context:
A new study on the susceptibility of Thwaites Glacier to marine ice cliff instability offers some optimism.
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- Antarctica’s Thwaites Glacier, often called the “Doomsday Glacier,” earned its ominous nickname due to the threat it poses to global coastlines if it were to collapse.
- Currently, the glacier is responsible for about 4 percent of annual sea-level rise as it loses ice.
- One theory suggests that the glacier could soon collapse into the ocean like a row of dominoes but the study offers some hope.
Thwaites Glacier’s Importance
- Thwaites Glacier plays a critical role in draining a vast portion of Antarctica’s ice sheet, covering around 74,000 square miles (192,000 square kilometres), an area larger than Florida.
- Any snowflake that falls within this drainage system will ultimately become part of an iceberg in the ocean off Thwaites.
- The situation at Thwaites Glacier is unfolding as a slow-motion disaster.
- The glacier rests on bedrock below sea level, which slopes downward as it extends inland. This means the glacier becomes deeper toward the interior of the ice sheet.
- Once Thwaites starts losing more ice than it gains from new snowfall and begins to retreat, this downward slope makes it extremely difficult to halt the process. Thwaites is already retreating at an accelerating pace due to climate warming.
- Thwaites Glacier contains enough ice to raise global sea levels by more than 2 feet (0.65 metres).
- If Thwaites destabilises, it could trigger the destabilisation of neighbouring glaciers as well.
Marine Ice Cliff Instability
- Many glaciers in Antarctica have large floating extensions known as ice shelves, which help to slow their flow into the ocean.
- As the climate warms, some of these ice shelves have collapsed rapidly, sometimes within just a few weeks or months.
- If the Thwaites ice shelf were to collapse, it would reveal a very tall ice cliff along its 75-mile (120-kilometre) front facing the ocean.
- Ice can only withstand so much force, so if the cliff is too tall, it could collapse into the sea.
- When this happens, a new, even taller ice cliff farther inland would be exposed, due to its greater height and distance from the ocean.
- The theory of marine ice cliff instability suggests that if these collapses occur quickly, they could trigger a chain reaction, with increasingly higher cliffs collapsing one after another.
- However, marine ice cliff instability has not been directly observed yet. Its occurrence depends on how quickly the ice collapses, making it uncertain whether this theory will hold true in practice.
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Indian Research Centres in Antarctica 1. Dakshin Gangotri (1983) Significance: This was India’s first permanent research station in Antarctica. It served multiple functions, including laboratories and accommodation, but was decommissioned in 1990 after being partially buried under ice. It now functions as a supply base and historical site. 2. Maitri (1989) Location: Schirmacher Oasis Significance: Maitri is the second permanent station and has been operational for over three decades. It conducts various scientific experiments in geology, geography, and medicine. The station is situated near Lake Priyadarshini, a freshwater lake, and has been instrumental in geomorphologic mapping of the region. 3. Bharati (2012) Location: Larsemann Hills Significance: Bharati is India’s newest research station, focusing on oceanographic studies and geological research related to the continental breakup of the Indian subcontinent. |