Pine Island Glacier is a large ice stream flowing west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica.
It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy air photos, 1960—66, and named in association with Pine Island Bay. The area drained by Pine Island Glacier comprises about 10% of the West Antarctic Ice Sheet.
Satellite measurements have shown that the Pine Island Glacier Basin has a greater net contribution of ice to the sea than any other ice drainage basin in the world and this has increased due to recent acceleration of the ice stream.
An international team of scientists from Lamont-Doherty Earth Observatory and British Antarctic Survey has discovered that due to an increased volume of warm water reaching the cavity beneath Pine Island Glacier in West Antarctica, it’s melting 50 percent faster than it was 15 years earlier.
The glacier is currently sliding into the sea at a rate of 2.5 miles a year, while its ice shelf (the part that floats on the ocean) is melting at about 80 cubic kilometres a year. “More warm water from the deep ocean is entering the cavity beneath the ice shelf, and it is warmest where the ice is thickest,” said lead author, Stan Jacobs, an oceanographer at Columbia University’s Lamont-Doherty Earth Observatory.
Dr Adrian Jenkins from British Antarctic Survey said, “Our research shows that the glacier melt rate has increased significantly because more warm water is circulating beneath it. It appears that the thinning of the ice shelf that has resulted from the higher melt rates is what has allowed the circulation to strengthen. It’s evidence of a complex feedback between glacier dynamics, seabed topography and ocean circulation that we need to understand if we are to say how Pine Island Glacier will evolve in the future.
The Pine Island and Thwaites Glaciers are two of Antarctica’s five largest ice streams. Scientists have found that the flow of these ice streams has accelerated in recent years, and suggested that if they were to melt, global sea levels would rise by 0.9—1.9 m (1—2 yards).
This MODIS image taken by NASA’s Aqua satellite on Nov. 10, 2013, shows an iceberg that was part of the Pine Island Glacier and is now separating from the Antarctica continent. What appears to be a connection point on the top left portion of the iceberg is actually ice debris floating in the water.
The original rift that formed the iceberg was first observed in October 2011 but as the disconnection was not complete, the “birth” of the iceberg had not yet happened. It is believed the physical separation took place on or about July 10, 2013, however the iceberg persisted in the region, adjacent to the front of the glacier.
The iceberg is estimated to be 21 miles by 12 miles (35 km by 20 km) in size, roughly the size of Singapore. A team of scientists from Sheffield and Southampton universities will track it and try to predict its path using satellite data.
Image credit: NASA