Melting of Antarctic Glaciers : A Major Cause of Rising Sea level

 

Global Warming:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

 

Melting of Antarctic Glaciers:

A Major Cause of Rising Sea level

 

The Pine Island and Thwaites glaciers, which sit side by side in West Antarctica on the Amundsen Sea, are amongst the quickest changing glaciers in the region, already accounting for 5% of global sea level rise. Scientists say the glaciers are incredibly sensitive to climate change. Satellite pictures show that two vital glaciers in the Antarctic are sustaining speedy damage at their most susceptible points, leading to the breaking up of crucial ice shelves with primary consequences for global sea level rise. A new study determined that the glaciers are weakening at their foundations and this harm over the previous few decades is speeding up their retreat and the possible future fall down of their ice shelves. The pictures confirmed incredibly crevasses areas and open fractures in the glaciers. From 1997-2019, the researchers, led by Stef Lhermitte, satellite specialist at Delft University of Technology in the Netherlands, used satellite information to record the increase of the damaged areas. While speedy ice loss and melt of these Antarctic glaciers have been properly documented, the new findings suggest that there should be future disintegration of the ice cabinets to come.

We knew they have been sleeping giants and these have been the ones losing miles of ice. However, how far away and how much still remains a large uncertainty. These ice shelves are in the early phase of disintegration, they are beginning to tear apart. Thwaites Glacier is one of the largest and most unstable glacier in Antarctica. It's a large mass of more than 74,000 sq miles which is almost the size of Great Britain. Two glaciers effectively act as arteries connecting the Antarctic ice sheet to the ocean. At their base are everlasting floating ice shelves that act as a buttress to the fast-flowing ice behind it. The area holds enough ice to raise international sea levels by 4 feet.

Human-induced warming of our oceans and atmosphere because of the increasing release of heat-trapping greenhouse gases is weakening the planet's ice shelves. This ocean warming has increased the melting and the breaking off of ice chunks of Pine Island and Thwaites glaciers, whilst declining of snow fall means the glaciers cannot replenish themselves. The researchers discovered and pointed to a weakening of the glaciers' shear margins, areas at the edges of the floating ice shelf the place where the speedy shifting ice meets the slower shifting ice or rock underneath. Typically, the ice shelf acts like sluggish traffic. It's floating on the ocean however it buttresses the ice traffic behind it. That's precisely what the researchers found  and they accept as true with these severely weakening components of the glacier will accelerate mass ice loss. The study makes the case that this system must be covered in models that project sea level rise, which it is no longer presently a part of it. Researchers observed that while the tearing of Pine Island Glacier's shear margins has been documented since 1999, their satellite images indicate that damage sped up dramatically in 2016.

Thwaites Glacier may be permitting warm ocean water to melt the underside of its ice. Cavities hidden underneath the ice shelf are probably to be the route through which warm ocean water passes beneath the ice shelf up to the grounding line. Over the last three decades, the rate of ice loss from Thwaites and its neighboring glaciers has increased more than five-fold. If Thwaites had been to collapse, it ought to lead to an increase in sea levels of around 25 inches. And, there may be more horrific information for glaciers on the other aspect of the world. Scientists announced that a 44 square mile chunk of ice, about twice the size of Manhattan, has broken off the Arctic's largest ultimate ice shelf in northeast Greenland in the past two years, raising fears of its speedy disintegration. The territory's ice sheet is the 2nd largest in the world behind Antarctica's, and its annual melt contributes more than a millimeter rise to sea levels every year. These current findings from Antarctica exhibit that the glaciers are "weakening from all angles," researchers said. Most of the weakening in this part of Antarctica is coming from below. Warm ocean water gets to the glaciers' base and weakens them. What we observed is that this will become so weakened, that they speed up and once they speed up, the shear margins speed up and start to break. It appears that the more we look at these systems evolve, the more we see motives for them to disappear more rapidly than we thought. We have to act shortly on controlling climate change to preserve our future. Act now together to reduce the speedy melting of Antarctic glaciers’ ice.

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Sources: cnn/BBC/CGTN and other international agencies