• Meltwater Ponds: Pools of water that form on the surface of ice shelves due to melting ice.
• Ice Shelves: Thick, floating sheets of ice that extend from the coastline over the ocean, acting as barriers that hold back the flow of glaciers from the land into the sea.
• Flexing and Fracturing: The bending and breaking of ice shelves caused by the weight and movement of meltwater ponds.
FAQS
How do meltwater ponds form?
Meltwater ponds form when warmer air temperatures cause the surface ice on ice shelves to melt. The liquid water then pools in depressions on the ice shelf.
Why are meltwater ponds a threat to ice shelves?
The weight of the water in meltwater ponds exerts pressure on the ice shelf, causing it to flex and eventually fracture. This can weaken the structural integrity of the ice shelf, leading to its collapse.
What happens when an ice shelf collapses?
When an ice shelf collapses, it can no longer hold back the glacier ice behind it. This can lead to increased flow of glaciers into the ocean, contributing to sea level rise.
What did the recent Antarctic expedition discover?
A team of scientists found that meltwater ponds caused significant flexing and fracturing of the George VI Ice Shelf. They observed that the ice was dropping and rising by about a foot due to the cyclic filling and draining of these ponds.
How does the process of flexing and fracturing occur?
1. Temperature Increase: Warmer air causes surface ice to melt, forming meltwater ponds.
2. Concentration of Weight: The water pools concentrate weight, exerting pressure on the ice.
3. Crack Formation: Water seeps into existing cracks, widening them over time.
4. Cyclic Weakening: Repeated filling and draining cause the ice to flex and weaken.
5. Sudden Fracture: Continuous stress from the water leads to sudden and catastrophic fracturing of the ice.
What historical event is linked to this phenomenon?
The collapse of the Larsen B Ice Shelf in 2002 is believed to have been caused by this process. Before its collapse, many meltwater ponds were observed on the ice shelf, indicating surface meltwater loading played a critical role.
How does the collapse of ice shelves affect global sea levels?
The collapse of ice shelves allows inland glaciers to flow more freely into the ocean, which can significantly contribute to global sea level rise. Since 1880, global sea levels have risen by eight to nine inches, with Antarctic ice melt being a major factor.
Why are these observations important?
Understanding the process of meltwater-induced flexing and fracturing helps scientists improve models to predict which Antarctic ice shelves are most vulnerable to collapse. This knowledge is crucial for forecasting future sea level rise and planning mitigation strategies.
SRIRAM’s
Share:
Get a call back
Fill the below form to get free counselling for UPSC Civil Services exam preparation
