In 2017, researchers predicted that the St. Patrick Bay ice sheets would disappear within five years. And they were right.

Recent satellite images taken by NASA’s Advanced Spaceborn Thermal Emission and Reflection Radiometer (ASTER) show that both ice sheets have now completely disappeared. And that makes them the most recent – but certainly not the last – victims of climate change.

Rapid demise
It has gone fast with the St. Patrick Bay ice sheets, says Mark Serreze who first visited the ice sheets in 1982. “When I first visited these ice sheets, they seemed to be such permanent landscape features. It is amazing to see that they disappear in less than 40 years. ”

In 1959, the largest St. Patrick Bay ice sheet covered 7.48 square kilometers. The smallest St. Patrick Bay ice sheet measured 2.93 square kilometers in the same year. However, in the years that followed, the ice sheets rapidly shrank. And in 2016, they were only 5 percent of that original size. In 2017, researchers – including Serreze – predicted that the ice caps would disappear within five years . And that prediction came true this month. Because ASTER – one of the instruments on board the TERRA satellite – revealed on July 14 that both ice caps have completely disappeared.

The downfall of the two Canadian ice sheets in the picture. 
The lines indicate the size in 1959, 2001, 2014 and 2015. 
Image: Serreze, MC, Raup, B., Braun, C., Hardy, DR, and Bradley, RS: Rapid wastage of the Hazen Plateau ice caps, northeastern Ellesmere Island, Nunavut, Canada, The Cryosphere, 11, 169–177,  https://doi.org/10.5194/tc-11-169-2017 , 2017.

Two more ice sheets over
The St. Patrick Bay ice sheets are located on Ellesmere Island, which is located in the Arctic Ocean. The two small ice caps that have now disappeared are part of a group of four ice caps that rest on the so-called Hazen Plateau. The remaining two ice sheets – the Murray and Simmons ice sheets – are a lot higher than the two disappeared ice sheets and therefore do better in certain circumstances. However, researchers expect that these ice caps will also disappear due to global warming.

On the left the ice caps in 2015. On the right a photo taken in July 2020: the ice caps are completely gone. 
Image: Bruce Raup, NSIDC.

“We have known for a long time that when climate change hits, its effects are particularly noticeable in the Arctic,” said Serreze. “But the death of these two little ice caps that I once knew so well made climate change very personal. All that’s left now are a few photos and lots of memories. ”

Follow-up research

Although the demise of the two ice sheets is regrettable, researchers also see opportunities at the same time. For example, the demise of the ice caps offers them the opportunity to investigate how plants colonize the suddenly ice-free polar landscape. And that can provide more insight into how the other bidding that will become ice-free in the short or longer term fares.

It is certain that the St. Patrick Bay ice sheets are by no means the last ice masses to disappear due to global warming. For example, the Greenland ice sheet has melted very hard in recent years and Antarctica has also lost an alarming amount of ice in recent decades. At the same time, there are also major concerns about the so-called tropical glaciers that we find in Peru, for example. Recent research indicates that of the 1973 glaciers in the country , about 170 have already disappeared . And the remaining glaciers are also melting hard. The same goes for the last glaciers in Indonesia and Papua. According to a study published last year, these glaciers could even be a thing of the past within ten years .

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