A massive iceberg four times the size of Manhattan has broken free from the Pine Island Glacier in Antarctica.
The mass of ice is around 103 square miles, and it broke free last weekend – Manhattan is only 22.83 square miles.
This marks the second time in just two years such a huge hunk of ice has been separated from the area.
Breaking news from Pine Island Glacier, which lost 267km2 of icebergs today, after the internal crack resulted in a large calving event 1/n pic.twitter.com/sLwGTyNTfC
— Stef Lhermitte (@StefLhermitte) September 23, 2017
Experts think that these processes show the glacier is beginning to deteriorate and ‘fall to pieces’.
A previous event saw an iceberg the size of Delaware fall into the sea from the Larsen C ice shelf only in July.
It has been speculated the phenomenon is due to warming sea temperatures in the area causing the ice to be melted from underneath.
The largest new iceberg of Pine Island Glacier (185km2) did get a name by USNIC: B44. https://t.co/EYTYY6kuZ4 Farewell B44 and brothers! pic.twitter.com/GteRJaN43W
— Stef Lhermitte (@StefLhermitte) September 26, 2017
Thankfully, this huge iceberg will not contribute to the rising sea level, as it separated from a piece of glacier which was already floating in the sea – much in the same way as a glass of water with ice cubes doesn’t overflow when the ice melts.
It isn’t all good news, however, as experts note the fact that the chunk of ice falling from the middle of the glacier points at a greater destabilisation of the ice in the area.
The incident was reported by Dr Stef Lhermitte, from Delft University of Technology, who posted to Twitter.
2015 & 2017 are different from previous events as the calving results from internal rifts with calving fronts further inland 4/n
— Stef Lhermitte (@StefLhermitte) September 23, 2017
He tweeted:
Breaking news from Pine Island Glacier, which lost 276km2 of icebergs today, after the internal crack resulted in a large calving event.
The glacier is one of the largest in West Antarctica, which is the region of Antarctica currently losing the most ice.
#Sentinel1 (23/9 vs. 21/9) shows the Pine Island glacier calving clearly and seems to indicate that the iceberg is falling in pieces 2/n pic.twitter.com/GVzOMDobj7
— Stef Lhermitte (@StefLhermitte) September 23, 2017
Pine Island Glacier loses around 45 billion tonnes of ice each year, resulting in one millimetre of sea level rise every eight years, and that is just this glacier.
If the whole glacier were to melt, it would contribute a total of 1.7 feet of sea level rise.
Experts have been watching the glacier closely – Seongsu Jeong and Ian Howat of Ohio State University published a paper just last year highlighting the trend of losing ice from the centre.
Dear @AntarcticPIG, this #Sentinel1 time-lapse shows your calving since 2015 and new rift growth @CopernicusEU @sgascoin @kryosat @ESA_EO pic.twitter.com/y1LOpuwbnU
— Stef Lhermitte (@StefLhermitte) January 31, 2017
Howat told The Washington Post:
We predicted that the rifting would result in more frequent calving, which is what’s happening here.
If new rifts continue to form progressively inland, the significance to ice shelf retreat would be high.
.@NASAEarth 's MODIS satellite gives an overview of #PIG's glacier front location since 2009 + corresponding 3 major calving locations 7/n pic.twitter.com/miP1RAUCBF
— Stef Lhermitte (@StefLhermitte) September 24, 2017
The ‘rift’ which caused this calving of ice was spotted (top image) as close as last year, and Ian Howat reckons more is yet to come.
He said there were more cracks presenting themselves as near as March 2017, so we could expect another calving event very soon.