The iceberg twice the size of Atlanta has been named B31 and is estimated to be 500 meters thick. The U.S. National Ice Center (NIC) reported that iceberg B31 is twice the size of Atlanta or about siz times the size of Manhattan. According to NASA, B31 was calved from one of the world’s largest icebergs, Antarctica's Pine Island Glacier last October. CNN reports on April 22 that the initial crack of B31 was spotted in 2011.
For the past five months, B31 has drifted out of Pine Island Bay into the Amundsen Sea off the western side of the continent, and the iceberg is now moving into the ocean off Antarctica. The "runaway" iceberg could threaten shipping during the dark Antarctic winter nights.
B31 is being well-tracked with the help of radar, satellite images, and two “37 javelin-shaped Aircraft Deployable Ice Observation Systems (ADIOS)” that were dropped onto the iceberg before it broke off. ADIOS is like a GPS tracker and is helping scientists to monitor the movement of B31. “Thanks to the early detection of its calving by the IceBridge program, we have been able to study its dynamics from early on in its lifecycle,” says David Jones of the British Antarctic Survey (BAS), according to NASA’s Earth Observatory.
The lifecycle of B31 began in October of 2011 when NASA scientists discovered a crack in the ice shelf at the end of the Pine Island Glacier in Antarctica. During the next two years, the crack grew bigger as Pine Island Glacier traveled faster than two miles per year. By November of 2013, B31 separated from Pine Island and drifted towards the open ocean. B31 was originally described as being 21 miles by 12 miles, eight times the size of Manhattan. Now it is about six times the size of Manhattan. According to NASA, B31’s movements vary from no motion to a rapid flow.
Kelly Brunt, a glaciologist at NASA’s Goddard Space Flight Center, is saying that the significance of B31 breaking off and “running away” is “still being sorted out.” Even though iceberg carving is a normal process, the crack that created B31 occurred much sooner than “the 30-year average calving front of Pine Island Glacier (PIG), so this a region that warrants monitoring.”
According to BAS (the British Antarctic Survey Natural Environment Research Council), “it is extremely likely (95-100% confidence) that human activities have been the dominant driver of global climate change since the mid-20th century. Antarctica, and the Southern Ocean that surrounds it, are integral to helping us predict the future of Earth’s climate system. Understanding Antarctica’s role in climate change is not only a huge scientific challenge but also an urgent priority for society.”
Antarctica covers an area larger than Europe and during the past 60 years, the average annual temperature in the Antarctic Peninsula has risen by up to 3.2°Celsius which has contributed to the collapse of some ice shelves. About 30 countries operate Antarctic research stations where scientists have found that reductions in most glaciers, like the break off by B31 from the Pine Island Glacier, is due to changes in air and ocean temperatures. “The present concentration of atmospheric carbon dioxide exceeds any value measured in ice cores covering the last 800,000 years.”