The Ross Ice Shelf in Antarctica, the largest ice shelf in the world. Some of the cold ice shelves that researchers originally thought would remain stable for centuries to come have turned out to be vulnerable as the planet warms further.
Stuart Rankin / NASA / Flickr (CC BY-NC 2.0)
Some cold ice shelves in Antarctica, which researchers originally thought would remain stable for centuries to come, are proving vulnerable as the planet warms further. That calls for a study Nature.
If an ice shelf has cracks, the water from those lakes can flow into it. This can cause the ice shelf to shatter in a short time.
When ice shelves break off, they themselves do not contribute to a rise in sea level because they are already floating in the sea. The land ice they hold back will flow faster into the sea, causing the sea level to be higher.
Researchers led by the Dutch climate researcher discovered this Melchior van Wessem. The results of the study have been published in Nature Climate Change.
Ross ice shelf
The largest ice shelf in the world is the Ross Ice Shelf in Antarctica. The large, floating ice sheet, hundreds of meters thick, is about the size of Spain. The plate is attached to the ice sheet on land. Although it is cold on all ice shelves of Antarctica, the average temperature on this ice shelf is even lower. Because of these cold conditions, climate scientists initially believed the Ross Ice Shelf and other similar ice shelves to be safe from global warming for the next century.
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Van Wessem’s research shows that these cold ice shelves also need to be monitored. That’s because cold ice shelves like the Ross Ice Shelf have relatively little snowfall, which can accelerate the formation of lakes of meltwater on these ice shelves, which is bad news.
If an ice shelf has cracks, the water from those lakes can flow into it. This can cause the ice shelf to shatter in a short time.
Melt water
More than 60 percent of the ice shelves in Antarctica, including the Ross Ice Shelf, have such cracks and so could potentially shatter as meltwater lakes form. If that happens, the adjacent land ice can flow more quickly into the sea and sea levels will rise.
Snowfall appears to play a much larger role than previously thought.
Meltwater lakes on cold ice shelves such as the Ross ice shelf already start to form at an average annual temperature of -15° Celsius. According to the latest climate models, with average global warming, those temperatures could already be reached on the Ross Ice Shelf by the end of this century.
Simulate snowfall
There is enough land ice in Antarctica to cause sea levels to rise by tens of meters worldwide.
‘What surprised me the most is that the amount of snowfall determines so strongly the threshold value for the formation of meltwater lakes,’ says Van Wessem.
‘With my research I tried to better predict the melting in Antarctica itself, but it now appears that snowfall plays a much greater role than previously thought. As far as I’m concerned, it’s just as important to improve the simulation of snowfall in Antarctica, so that the models we use to make predictions about the melting of the ice cap and the resulting sea level rise become more accurate.’
