At the University of Maryland, the University of California and the University of Leeds, scientists reviewed satellite measurements of decades and revealed the secrets behind why and how Antarctica’s ice shelves, glaciers and sea ice have been changing.
Andrew Shepherd, professor of Earth observation with the University of Leed’s School of Earth and Environment and lead author on the review mentions, Antarctica is too big to be surveyed from the ground, and it is only understandable by reviewing trends of its ice cover by observing the continent from space.
On a report published by the associated scientists from the universities, on a particular Antarctica based issue in the journal, Nature on 14th June, revealed how the continent’s thinning of the ice shelf and its collapses have contributed in the rise of the sea level. The researchers have also found that though the overall area of the sea ice around the continent may have shown very little change overall ever since the introduction of the satellite observations, the 20th-century ship-based readings project a much higher long-term decline.
Around 150 and more studies on the subject have been conducted to determine how much of these ice shelves are continuously lost. The most significant changes have been seen around places where these protective barriers – the ice shelves have either collapsed or thinned. In the West Antarctica region, these ice shelves are being digested by the warm ocean water. The shelves around the Bellingshausen and Amundsen seas have thinned almost 18 per cent since the 1990s. Also, the ice shelves collapsed as its surfaces melted away with rising temperatures by the Antarctic Peninsula. Since the 1950s, almost 34,000 square km (around 13,000 square miles) ice shelf area is lost.
As the satellite readings and observations keep on providing detailed views of Antarctic ice cover helping researchers to gauge the age, intensity, motion and as well mapping the thickness of ice, some other findings of the researches are:
● The entire continent is covered with around 6 million square miles (15.5 million square km) ice, that gathered for over thousands and thousands of years of snowfall and the fresh snow weight compressing the older below forming solid ice.
● At the Southern Ocean in Antarctica, the sea ice tends to expand and contracts as throughout the year the water of the ocean freezes and melts. The sea ice covers around 7 million square miles (18.5 million square km) during the winters and gets to about a meter, almost 3 feet thick.
● The glaciers flowing from these ice sheets expand with their weight while rushing towards the ocean and thus lose its contact with bedrocks. These forms around 300 odd floating shelves of ice that surrounds the continent. These floating shelves contribute to almost 10 per cent of the continents total ice.
● Enough of water is locked in these ice sheet to raise the sea levels globally to more than 164 feet (50 meters).