Climate Wire | For decades, the Steenstrup Glacier was one of Greenland’s most stable ice belts. Then, in 2018, it suddenly began to retreat inland, shrinking as the ice was dumped into the sea. By 2021, the retreat rate has quadrupled and the amount of ice pouring into the ocean has doubled.
This is one of the fastest accelerated ice melts scientists have ever observed from a Greenland glacier. And it may be a warning sign for the future.
A new study suggests that an influx of warm deep water is likely to blame.The deep waters around Greenland are heating up over time. That said, episodes of this kind could happen even more frequently in the future.
That’s cause for concern. Greenland is already the largest contributor to global sea level rise, losing about 250 billion tonnes of ice each year.
Collapsing glaciers at the edge of the ocean account for about half of these losses, with the other half coming from melting ice on the surface of the ice sheets. As glaciers retreat at a faster rate, more ice is released into the ocean, further increasing the rate of sea level rise.
Steenstrup’s actions raise concerns about how stable glaciers will respond to future warming.
“The fact that glaciers have quadrupled in just a few years raises new questions about how quickly giant ice packs can actually respond to climate change,” said the study’s lead author. Author and Research Fellow at Durham University, UK, Thomas Chudley. in a statement.
In this study, we examine the sudden destabilization of Steenstrup. Prior to 2018, the glacier had changed little for decades. But between 2018 and 2021, it has retreated nearly 4.5 miles inland.
During this time, the amount of ice flowing from the glacier into the sea doubled. By 2021, more than 6 billion tonnes of ice will be lost annually, putting Greenland in the top 10% of ice-losing glaciers.
The cause was not immediately clear.
Many other glaciers southeast of Greenland, where Steenstrapp is located, have seen an increase in their retreat rate since 2016. Scientists believe that multiple causes are responsible. Higher temperatures help heat ocean waters near the surface, and these warmer surface waters can accelerate the melting of glaciers.
Additionally, the water in front of many coastal Greenland glaciers is often filled with clumps of floating ice and slush known as ice mélange. Warm surface water breaks down the mélange, removing its extra support sources and allowing the glacier to melt even faster.
But the authors of the new study find that none of these factors appear to play a major role in Steenstrup. I’m assuming it’s speeded up.
Steenstrup is surrounded by shallow waters that are generally not affected by deep currents. However, according to data and model simulations, a large influx of warm deep water in the region in 2018 appears to have rapidly destabilized the glacier.
After 2021, Steenstrup appears to have slowed down again. But it poses new questions to scientists about how climate change might affect glaciers previously thought to be stable or safe.
For decades, Steenstrup was relatively isolated from the effects of warm air and rising surface water temperatures, but a sudden influx of deep, warm water was enough to put it in dangerous territory. , meaning other oceans may follow suit, especially as water temperatures continue to warm around Greenland.
“Steenstrup showed that glacier stability is difficult to predict with current knowledge,” the researchers said. Better ground observations of the region will help scientists gain more insight into how climate change is affecting Greenland’s glaciers.
And these insights could help scientists make ice forecasts for other parts of the world, including vulnerable regions of Antarctica.
“What’s happening in Greenland now is like a canary in a coal mine that may happen in West Antarctica over the next few centuries,” Chudley said. “So it would be great if we could go into the fjord with a real ground observation and see how and why the Steenstrapp changed.”
Reprinted from E&E News with permission of POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.
