“These are very early results from a very localised area and so need to be taken in context when looking at an ice shelf the size of Spain through a 25 centimeter hole,” Alex Brisbourne, a glaciologist with the British Antarctic Survey and who wasn’t involved in the project, told IFLScience.
Instead of uniform warming and thawing across the continent, the BAS highlights that the “Antarctic Peninsula and large parts of West Antarctica warmed significantly over the second half of the 20th century” in comparison to its other realms, where temperatures have remained somewhat stable over the past few decades.
This variation in warming, along with a handful of other factors, mean that Antarctica’s ice – land or sea-based – is responding unevenly to the rising mercury.
“The Ross Ice Shelf is generally regarded as stable,” Brisbourne added. Unlike plenty of other ice shelves in the region, Ross has not experienced a “warm water incursion beneath, or warm atmosphere above, and so hasn't thinned as rapidly.
“We know of processes occurring beneath ice shelves with a ‘cold cavity,’ such as the Ross, which can result in both melting and localised freezing, which is what these ice crystals at the base indicate,” Brisbourne added. “As such, these results are perhaps not that surprising.”
As the Ross is so “poorly studied,” however, this study will be “extremely useful” when it comes to understanding its present and future behaviour.
In any case, such pioneering research underscores the fact that both climate change and ice shelves are complex phenomena. This isn’t a simple X leads to Y situation, and the new result from the Ross Ice Shelf encapsulates this rather strikingly.
Ice shelves are already on the sea, so their collapse doesn’t directly translate to a rise in sea level. Such shelves, however, do hold back a lot of landlocked ice, and their disappearance can potentially open the metaphorical and literal floodgates, like removing a blockage from a drain.
The Ross Ice Shelf’s vulnerability to climate change, then, is a key research query with significant implications. This latest finding simply adds an extra layer of complexity to its behavior.