After forming a nearly 20-mile rift across the retreating Pine Island Antarctic glacier in early September, there are now approximately 115 square miles of ice – more than five times the size of the area Manhattan – in the Pyrenees
The largest chunk of ice is four times larger than Manhattan
This ice-cold event enhances the history of the melting and retreating of Antarctic glaciers, especially due to the relatively warm oceans that have eaten the ice from below.
"This retreat and weakening are driven almost exclusively by a thinning driven by the melting of the ocean on the ground," said Stef Lhermitte, a remote sensing geoscientist at Delft University of Technology in the Netherlands. 1
Ice shelf – these are the ends of massive Antarctic glaciers that overflow the sea – break into the sea regularly.
But today, when the ice thins out from below, the ice breaks faster into the sea than it can replenish naturally.
"At the beginning of the 2000s, it was about every 6 years, but the frequency of calving has increased since 2013," said Lhermitte.
"The resulting icebergs also disintegrate faster, as happened yesterday in the iceberg."
These pails play a big role.
They are especially useful as pegs, often clinging to the bottom of the sea and retaining the shape of the Antarctic Ice floes flow unhindered into the ocean.
With more ice retreat, like this last instance, the shelf shelf loses more foot and becomes increasingly vulnerable to collapse.
In short, the plug can dissolve in the ocean, eventually leading to sea-level rise.
In early 2000, major PIG calving events took place every ~ 5 years (2001, 2007, 2011), but since 2013 there have been 4 (2013, 2015, 2017, 2018). Consequently, the glacier front retreated strongly from the zone 1972-2013 and is now about 5 km further inland than in the years 2015-2017 2/2 pic.twitter.com/8O7gPyQAmh
– Stef Lhermitte October 30, 2018
Such major collapses are relatively new and largely unprecedented in human history, so it is not known how fast this could happen – perhaps in this century or shortly thereafter.
"We really do not know how fast they will collapse," NASA oceanographer Josh Willis said in September.