A recent study has revealed that the rising temperatures of the Atlantic Ocean are putting previously stable glaciers at risk.
According to a recent study, a once highly stable glacier in Greenland is now retreating at an unprecedented rate, likely due to the effects of rising ocean temperatures caused by climate change.
A team of researchers from The Ohio State University recently discovered that Steenstrup Glacier in Greenland has undergone a significant transformation from 2018 to 2021. The glacier has retreated a distance of approximately 5 miles, experienced a 20% decrease in thickness, and seen a doubling in the amount of ice it releases into the ocean. Furthermore, its velocity has quadrupled. This makes it one of the top 10% of glaciers that contribute to the total ice discharge in the region.
The study was recently published in the journal Nature Communications.
The Steenstrup Glacier is part of The Greenland Ice Sheet, a body of ice that covers nearly 80% of the world’s largest island, which is also the single largest contributor to global sea rise from the cryosphere, the portion of Earth’s ecosystem that includes all of its frozen water. While the region plays a crucial part in balancing the global climate system, the area is steadily shrinking as it sheds hundreds of billions of tons of ice each year because of global warming.
Over the past few decades, much of this loss has been attributed to accelerated ice discharge from tidewater glaciers, glaciers that make contact with the ocean. Many glaciologists believe that this recent uptick in ice discharge can be explained by the intrusion of warming waters that are being swept from the Atlantic into Greenlandic fjords – critical oceanic gateways that can impact the stability of local glaciers and the health of polar ecosystems.
The research team aimed to test that theory by examining a glacier in the southeastern region of Greenland called K.I.V Steenstrups Nordre Bræ, an entity more colloquially known as the Steenstrup Glacier.
“Up until 2016, there was nothing to suggest Steenstrup was in any way interesting,” said Thomas Chudley, lead author of the study, who completed this work as a research associate at the Byrd Polar and Climate Research Center. Chudley is now a Leverhulme research fellow at Durham University in the UK.
“There were plenty of other glaciers in Greenland that had retreated dramatically since the 1990s and increased their contribution to sea level rise, but this really wasn’t one of them.”
As far as scientists knew, Steenstrup had not only been stable for decades but was generally insensitive to the rising temperatures that had destabilized so many other regional glaciers, likely because of its isolated position in shallow waters.
It wasn’t until Chudley and his colleagues compiled observational and modeling data from previous remote sensing analyses on the glacier that the team realized Steenstrup was likely experiencing melt due to anomalies in deeper Atlantic water.
“Our current working hypothesis is that ocean temperatures have forced this retreat,” Chudley said. “The fact that the glacier’s velocity has quadrupled in just a few years opens up new questions about how fast large ice masses can really respond to climate change.”
In recent years, glaciologists have been able to use satellite data to estimate the potential volume of glacial ice stored at the poles and how it might affect current sea levels. For instance, if the Greenland Ice Sheet were to melt, Earth’s sea levels could rise by nearly 25 feet. In contrast, if the ice sheet in Antarctica were to fall apart, it’s possible that oceans would rise by nearly 200 feet, Chudley said.
While Greenland and Antarctica would take centuries to collapse completely, the global cryosphere has the potential to cause sea levels to rise about six feet this century if the West Antarctic Ice Sheet undergoes collapse.
As around 10% of the planet’s population lives in low-lying coastal zones, Chudley said that any significant rise in sea level can cause increased risk to low-lying islands and coastal communities from storm surges and tropical cyclones.
In the United States, sea level rise poses a particular risk to coastal cities in places like Florida or Louisiana, Chudley said. But that doesn’t necessarily mean it’s too late to stop such a future from happening. If climate policies evolve rapidly, humans might have a chance at halting the worst of sea level rise, Chudley said.
Overall, Steenstrup’s unique behavior reveals that even long-term stable glaciers are susceptible to sudden and rapid retreat as warmer waters begin to intrude and influence new environments.
While the research says continued scientific observation of the Steenstrup Glacier should be a priority, it concludes other similar glaciers also deserve attention because of their potential to retreat due to warming waters.
Understanding more about these interactions could provide key insight into how glaciers thrive in other locations around the world and even become an indicator of how these environments might change in the future.
“What’s happening in Greenland right now is kind of the canary in the coal mine of what might happen in West Antarctica over the next few centuries,” Chudley said. “So it would be great to be able to get into the fjord with real on-the-ground observations and see how and why Steenstrup has changed.”
Reference: “Atlantic water intrusion triggers rapid retreat and regime change at previously stable Greenland glacier” by T. R. Chudley, I. M. Howat, M. D. King and A. Negrete, 19 April 2023, Nature Communications.
The study was funded by NASA. Other Ohio State co-authors were Ian M. Howat and Adelaide Negrete of the Byrd Polar and Climate Research Center. Michalea D. King of the University of Washington was also a co-author.
“…, if the Greenland Ice Sheet were to melt, Earth’s sea levels could rise by nearly 25 feet.”
It is common to observe terminal moraines, and strand lines from glacial lakes, that are repetitive. That is, the glaciers had a terminus that was in a constant position for a period of time, retreated suddenly, and then took up a new position for an indeterminate period. Attempting to extrapolate long-term retreat based on a retreat episode is bound to give a rate of retreat that is much too high.
Most estimates of the rate of Greenland Ice Sheet loss suggest several thousand years before that potential 25′ of sea level rise would be reached. The low-elevation, thin snouts near, or in, the ocean will melt and retreat faster than the high-elevation, thick, cold areas far from water. In several thousand years, there is high probability that we will experience another glaciation. Let’s hope that there is lots of greenhouse gases present at that time, because an ice sheet would be much more difficult for the world to deal with than rising sea level.
It is unrealistic to believe that there is more than a few hundred years of accessible coal, and more than a few decades of ‘cheap’ crude oil. The rate of emission of anthropogenic CO2 will decline significantly, out of necessity. Let’s further hope that we have solved the problem of controlled thermonuclear fusion long before we run out of the basic resource for plastics and chemicals.
One thing to consider, is that with what we know now, lithium will be an essential requirement for a neutron blanket for thermonuclear reactors, to breed tritium. It would be a serious mistake to have used all the readily available lithium for batteries, which will be buried and diluted after a few decades, in order to reduce CO2 that will decrease anyway. Those in control of our energy future have a short-term vision, and won’t be around to take responsibility for their mistakes. And there are far too many voters that have a misplaced trust in what their elected leaders, mostly lawyers and professional politicians, tell them about technology.
The geological climate of the Earth is still a 2.58-million-year ice age named the Quaternary Glaciation. The Earth is in a warm interglacial period that happens about every 100,000 years and lasts about 10,000 years which alternates with a cold glacial period that lasts about 90,000 years. The Earth still has around 200,000 glaciers and 11 percent of the land is permafrost. The ice age the Earth is in won’t end and the climate won’t officially change until all the natural ice melts. https://en.wikipedia.org/wiki/Quaternary_glaciation