Thanks to a combination of climatological quirks and man-made climate change, the Arctic is warming faster than anywhere else on the planet, and the Greenland Ice Sheet – the world’s second largest – is being obliterated at a remarkable rate.
A new study, published in the Journal of Geophysical Research – Earth Surface, reveals that something rather unfortunate is also going on beneath Greenland’s ice. Using a combination of modeling and imaging techniques, scientists have produced a subglacial map which shows that much of the underlying ice is wet, fragmented and mobile, providing the more solid ice on top to slide across the land and, ultimately, into the sea.
Although the center regions are stable, the thawed edges appear to be incredibly vulnerable to slippage. If there is a collapse or acceleration of slippage at the boundaries, the more solid core ice will also begin to slide downslope in a negative cycle of glacial disintegration.
“We're ultimately interested in understanding how the ice sheet flows and how it will behave in the future,” lead author Joe MacGregor, a glaciologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement.
“If the ice at its bottom is at the melting-point temperature, or thawed, then there could be enough liquid water there for the ice to flow faster and affect how quickly it responds to climate change.”
Although this study looks at a natural process, it is one that highlights just how bad ice loss and sea level rise via anthropogenic climate change will be in the near future.
It’s also worth noting that the more ice that’s lost in the Arctic, the less incoming solar radiation our planet will be able to reflect – and as a result, the Arctic heats up, and more ice melts, and so on. We’re losing our icy shield against global warming, and this study shows just how fast we might be losing it.
How the base of Greenland's Ice Sheet is holding up. The edges are almost all thawed. NASA Earth Observatory/Jesse Allen