Scientists have made an unsettling discovery in Antarctica, as two recent papers published in Nature outline. Thanks to several years’ worth of satellite imagery and data of remote areas of Antarctica, scientists were able to identify a vast system of pools and streams of meltwater across the continent. Although this isn’t a new development, scientists have known for decades of the presence of meltwater, but they hadn’t realised the extent of the systems and just how badly it had been exacerbated by climate change.
As the papers explain, the scientists were able to determine that meltwater could be displaced almost a mile by rivers and lakes carved into the ice, potentially infiltrating crevices and rifts, further weakening the ice shelf. In its’ gravity-driven quest to drain, the meltwater continues to carve into glaciers and ice shelves, creating a feedback loop whereby more meltwater is created through its’ transportation, as Columbia University glaciologist and paper co-author Robin Bell clarifies:
“It’s basically acting like an additional load on the ice shelf, which stresses it and causes it to fail”
In the past, meltwater was controlled by the local environment’s temperature, with there being a balance between freezing and melting of the continental ice. With rising temperatures continually affecting Antarctica, the fragile equilibrium seems to have been broken, with the ice melting at a faster rate than it can freeze. Scientists are worried that this latest discovery could mean the ice caps could be more unstable than previously thought.
Added pressure from meltwater could increase the rate of ice shelf degradation, increasing the likelihood of calving whilst also dumping more freshwater in the ocean, intensifying rising sea levels. However, the team led by Bell was able to find a silver lining in their discovery: a major drainage system. Indeed it seems as the majority of the meltwater is being funnelled to a drainage site, in this case a waterfall created off of East Antarctica’s Nansen Ice Shelf.
This waterfall has managed to successfully stabilize that side of the ice shelf by dumping the meltwater directly without giving it the opportunity to pool, accumulate and weaken the surrounding ice shelf. Scientists were glad to observe the Antarctic environment attempting to adapt to new factors, but they are unsure if it will be able to cope with a further increase in melting rates as fellow glaciologist from the University of Washington Knut Chistianson explains:
“This is the first time, to my knowledge, that such adaptability has been documented so comprehensively. Incorporating surface hydrology into ice-sheet-scale modeling is a relatively new endeavour. Work in these areas has begun, but the continental-wide observations (requiring high-resolution imagery) have only recently become available, and the scientific understanding must be grounded in these new observations, so there’s still much to be done.”