A crack in an ice shelf in Antarctica that is more than 100 miles (160km) long has grown by another 6 miles (9.6km) in a little more than two weeks this month, British scientists reported Thursday. That’s on top of an 11 miles (17km) growth that occurred in the second two weeks of December, creating a 17 mile (27km) total increase in not much more than a month. Once the crack is complete, it will form a giant iceberg larger than Rhode Island and almost as big as Delaware. The iceberg would be one of the largest icebergs on record.
The break “will fundamentally change the landscape of the Antarctic Peninsula,” according to Project MIDAS, a British Antarctic research project that’s tracking the crack, USA Today reported.
— Post Green (@postgreen) January 19, 2017
According to the National Snow and Ice Data Center, an ice shelf is a permanent floating sheet of ice that connects to a land mass and only a final 12 miles of ice remains connecting the future iceberg to its parent ice shelf.
The rift on Larsen C has grown by another 10 km since the start of 2017, bringing its total length to around 195 km: https://t.co/vUS123dLoJ
— Project MIDAS (@MIDASOnIce) January 19, 2017
The crack in the ice shelf, known as Larsen C ice shelf, been growing at an accelerating rate. Since the beginning of December, the rupture had already extended by 11 miles (18km) in length, after extending 13 miles earlier in previous year. The fissure has grown about 50 miles (80 km) since 2011, to a length of almost 100 miles (160 km) in total, and has widened to well around 1,000 feet. Now, only 12 miles (19 km) of ice continue to connect the chunk with the rest of the iceberg. A widening rift running is now running the length of the finger-shaped, 350-metre (160-feet) -thick floating ice block on the eastern side of the Antarctic Peninsula comes from the EU’s Sentinel-1 satellite system.
When it breaks away, the loss would be of nearly 2,000 square miles (5,000 square km) and nearly 100 storeys deep of ice, say the researchers with Project MIDAS, a British government-funded collaboration based at Swansea and Aberystwyth universities in Wales.
Most of the world’s ice shelves hug the coast of Antarctica. The West Antarctic ice sheet (the portion of the continent that juts out toward South America), where Larsen C is located, it holds enough frozen water to raise global oceans by about 20 feet (six metres). Once the iceberg sheared off, it would float along the coast of Antarctica, then head out into the Southern Ocean.
The real danger is from landward glaciers. Ice chunks float on the ocean, extending from the coast, and are slowly fed by glaciers from the ice sheet on land. They act like giant brakes, preventing the glaciers from sliding directly into the ocean. Scientists fear that If the glaciers held in check by Larsen C spilt into the Antarctic Ocean, it would lift the global water mark by about four inches (10 centimetres). The nearby Larsen A ice shelf collapsed in 1995, and Larsen B dramatically broke up seven years later. The ice block currently separating from Larsen C contains about 10 percent of the ice shelf’s mass, Swansea’s Professor Adrian Luckman said.
NASA scientist Thomas Wagner said. “Ice shelves serve a critical role in buttressing ice that’s on land,” he said.
There is not enough information to know whether the split is a result of climate change or not, but recent studies have suggested that drastic climate change may already have blamed large chunks of West Antarctica to disintegration in recent years. The breaking off, or calving, of ice shelves occurs naturally. But global warming is thought to have accelerated the process.