Larsen C ice shelf inching closer to detachment and collapse into the ocean ,to affect sea levels
Antarctic,July7:One of the world’s biggest icebergs, the Larsen C ice shelf, an extension of the West Antarctic ice sheet, is inching closer to detachment and collapse into the ocean, having an adverse impact on the region and on sea levels around the world.
The ice sheet, more than half the size of Qatar, is 2,000 square kilometres in area and is set to float off into the Weldell Sea, south of the tip of South America. If it breaks free, it will be the size of four Londons or more than seven New Yorks, CNN reported.
As per NDTV, scientists have been monitoring the progress of a crack across the ice shelf which extended to over 100 miles in recent months. Scientists from NASA and University of California, Irvine, found that the iceberg remains connected to the larger ice shelf only across a thin five-kilometre section. The parts which have already detached from the ice shelf have moved rapidly seaward, widening the rift while the remaining ice is “strained near to breaking point”, according to Adrian Luckman, a scientist monitoring Larsen C at Swansea University in Wales.
Researchers from the European Space Agency (ESA) used satellite measurements to discover that the iceberg will tower 623 feet (190 meters) high over the ocean’s surface and contain 1,155 cubic kilometers of ice, according to Live Science. It further noted that scientists observing the shelf have said it’s tough to predict the exact date when it’ll break away but it is matter of days or weeks before it happens. It could pose a danger to ships at sea as well.
Project Midas regularly updates the status of the Larsen C ice shelf and is run by Luckman as well. One of its latest summaries updates on the ice shelf reads:
In the largest jump since January, the rift in the Larsen C Ice Shelf has grown an additional 17 km (11 miles) between May 25 and May 31 2017. This has moved the rift tip to within 13 km (8 miles) of breaking all the way through to the ice front, producing one of the largest ever recorded icebergs. The rift tip appears also to have turned significantly towards the ice front, indicating that the time of calving is probably very close.
The rift has now fully breached the zone of soft ‘suture’ ice originating at the Cole Peninsula and there appears to be very little to prevent the iceberg from breaking away completely.
Antarctica has lost ice shelves earlier but none as huge as this one. A Washington Post report suggests one of the reasons this is important: Losing Larsen C ice shelf would not just change the entire map of the Earth but stop holding back glaciers capable of contributing about four inches of global sea level rise over time.
However, scientists are divided over the impact of global warming on this particular break in Antarctica’s ice shelf. Another report by the Washington Post quoted Helen Amana Fricker, an Antarctic scientist at the Scripps Institution of Oceanography, who wrote recently,”We do not need to press the panic button for Larsen C. Large calving events such as this are normal processes of a healthy ice sheet, ones that have occurred for decades, centuries, millennia — on cycles that are much longer than a human or satellite lifetime.”
But there are several others who disagree and believe this calving is a product of human-caused global warming. “Of course this is due to climate warming in the peninsula,” Eric Rignot, a NASA and University of California Irvine expert on Antarctica, told the Washington Post in an email.
CNN reported that Larsen C is not the first major ice shelf to break off. In the last three decades, Larsen A and B have also partially broken from the shelf. That’s a big deal, especially for a frozen mass in one of the quickest warming areas on Earth, according to NASA. The breakage of Larsen C will lead to more vulnerability as the deeper ice the Larsen C had once shielded is expected to become vulnerable to melting and disintegration, especially with rising temperatures.