Canadian officials announced Tuesday that two chunks of ice measuring together almost eight square miles (20 square kilometers) have broken off an Arctic ice shelf on the northern Canadian coast.

According to satellite pictures, the enormous masses of ice split away from the Ward Hunt shelf on the coast of Ellesmere Island in the Canadian Arctic Archipelago. Officials said they form two floating islands of ice measuring four to five square kilometers (1.9 square miles) and 14 square kilometers (5.4 square miles).

The pieces had been a part of the shelf for 3000 years and these are believed to be the largest pieces of ice shed in the region since 60 sq km of the nearby Ayles ice shelf broke off in 2005.

Scientists say additional separations could happen during the Arctic summer melt.

The North Pole is once again going through a speedy ice retreat this year, although many scientists believe it is unlikely that the record minimum extent of 4.13 million sq km (1.59 million sq miles) of sea-ice seen in 2007 will be broken.

Nevertheless, spectacular alterations are taking place in the region, affecting the ice both in the open ocean and the ice that is appended to the coast.

Researchers had foreseen that the Ward Hunt Ice Shelf (WHIS) was expected to suffer a considerable calving incident of this sort.

Of late, scientists traveled with the Canadian armed forces to inspect the area and found important new cracks in the ice that ranged for more 16km (10 miles).

Ellesmere Island was once bordered by one gigantic ice shelf that spread over almost 10,000 sq km (3,500 sq miles).

Presently, this spread of ice has retreated into a string of much smaller, individual shelves, which together cover just less than 1,000 sq km (400 sq miles). At 440 sq km (170 sq miles) in size and 40m (130ft) thick, the WHIS is the biggest of the remnant shelves. Scientists have been studying the Canadian feature because of what it can tell them about Arctic past.

An analysis of past records indicates that since the early 20th Century, the ice that constitutes the WHIS has retreated by about 90%.

Scientists believe the mechanism that has kept its stability - fresh water coming out of Disraeli Fjord and freezing under the shelf - may have been unbalanced. If that is the case, the rest of the WHIS may vanish quite rapidly.

Disintegration of sea-ice in the Arctic has global implications. The "white parasol" at the top of the planet reflects energy from the Sun right back out into space, aiding the Earth to cool.

Additional loss of Arctic ice means the Earth's climate may warm at an even faster rate than current observational data shows.