Sometimes nature throws us for a loop by doing something so spectacular that we can’t tell if it’s man-made (or alien made) or naturally occurring. And NASA just took a photograph of a rectangular iceberg that made the world ask that very question.
During a flyover to survey a different iceberg as part of Operation Icebridge, IceBridge senior support scientist Jeremy Harbeck took interest in a peculiarly shaped iceberg that had broken off the Larsen C ice-shelf in Antarctica.
Usually, when we think of icebergs we think of the jagged, pyramidal or rounded pieces of ice floating above the surface that are even more massive below the water line.
But the iceberg spotted by Harbeck was nearly perfectly rectangular as if a professional ice sculptor cut it to look that way.
However, this isn’t the work of humans. It’s the handy work of Mother Nature herself.
“I often see icebergs with relatively straight edges, but I’ve not really seen one before with two corners at such right angles like this one had,” Harbeck said in a statement according to NASA. “I was actually more interested in capturing the A68 iceberg that we were about to fly over, but I thought this rectangular iceberg was visually interesting and fairly photogenic, so on a lark, I just took a couple photos.”
Here’s the photo via Twitter.
From yesterday’s #IceBridge flight: A tabular iceberg can be seen on the right, floating among sea ice just off of the Larsen C ice shelf. The iceberg’s sharp angles and flat surface indicate that it probably recently calved from the ice shelf. pic.twitter.com/XhgTrf642Z
— NASA ICE (@NASA_ICE) October 17, 2018
Harbeck’s photo has gone viral, capturing the interest of people around the globe who sought an explanation from scientists.
And they had answers.
As it turns out, this iceberg is called a tabular iceberg, and they look the way they do because they have freshly broken off a larger ice-shelf, which is why they have sharper edges and more defined angles. The effects of erosion from wind and water have not shaped them into the icebergs we know so well.
Sea ice specialist Alek Petty, who is on the Icebridge research team, compared the sharp and straight fracture lines to breaking a glass plate while speaking to NRR.
“You can just get these fracture lines that can form these interesting geometric structures,” he said.
NASA and University of Maryland ice scientist Kelly Brunt explained the phenomenon to Live Science.
“So, here’s the deal,” she said. “We get two types of icebergs: We get the type that everyone can envision in their head that sank the Titanic, and they look like prisms or triangles at the surface and you know they have a crazy subsurface. And then you have what is called ‘tabular icebergs.'”
Antarctic Climate & Ecosystems Cooperative Research Center marine glaciologist Jan Lieser told CNN that’s he’s seen a lot of tabular icebergs.
“It’s a natural occurrence, it’s beautiful, but nothing out of ordinary,” he said. “I’ve seen many icebergs around Antarctica that have very straight, very long sides. There’s no one going around with a chainsaw and chopping it off. Nature does sometimes go on square angles.”
The State University of New York at Buffalo geophysicist Kristin Poinar says the reason why the iceberg is so rectangular and flat is because” the Larsen C is a large ice shelf. The ice has time to spread out and become perfectly flat.”
However, Poinar also points out that while the iceberg looks pristine and perfectly rectangular and flat, we’re really only seeing about 10 percent of the iceberg and that “if you look a little closer, they’re really mangled and full of cracks.”
University of Idaho glaciologist Timothy Bartholomaus explained to NBC News how tabular icebergs occur, but also warned that they are a sign of increasing climate change as warmer temperatures cause the polar caps to melt.
“Icebergs detaching from the edges of these ice shelves are like corners of a sheet of office paper getting cut with a pair of ocean-scissors,” he said. “Right after the cut, when the iceberg detaches, the edges will often be perfectly square.
“[T]he presence of icebergs like these are a sign of increased calving,” he continued. “Humans are warming the climate. Globally, we see very clear increases in air temperature that can only be explained through human-caused carbon emissions. In Antarctica, the specifics are more murky.”
Indeed, the Larsen C ice-shelf suffered a gigantic break last year when an iceberg the size of Delaware weighing a trillion tons broke off in the Weddell Sea where Harbeck snapped his photograph of the rectangular iceberg, alarming climate scientists.
“The iceberg is one of the largest recorded and its future progress is difficult to predict,” Swansea University Professor Adrian Luckman wrote in 2017. “It may remain in one piece but is more likely to break into fragments. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters.”
Dr. Martin O’Leary, Luckman’s colleague, wrote that while the iceberg does not pose a threat to global sea levels if it melts due to the fact that it was already floating in the ocean, it could cause other pieces of the ice shelf to break off, and at the very least threaten shipping lanes.
“Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position,” O’Leary said “This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable…Our models say it will be less stable, but any future collapse remains years or decades away.”
That’s not exactly a lot of time to prevent further collapse. If enough of the ice-shelf breaks off, land glaciers could end up reaching the ocean, which would add to sea-level rise that threatens to flood coastlines around the world.
In short, natural events could combine with man-made events to make the effects of climate change worse.
And pollution and increased greenhouse gases could result in speeding up these “natural events,” which means we’ll have to deal with worse climate change sooner than we think.
Scientists have long worried that Antarctica is melting, just as they are seeing with ice in Greenland and in the Arctic Circle, also known as the North Pole. One thing scientists don’t see very much in Greenland is rectangular shaped icebergs.
NASA researcher Eric Rignot points out that “the ‘bergs detaching from Larsen C are so big, they look perfectly rectangular or with linear features because they were created from rifts that run across the ice shelf for hundreds of kilometers straight. In Greenland, you would not find these rectangular bergs so much because it is warmer, icebergs break into smaller pieces and the glaciers are smaller as well.”
So, while it’s fascinating to see these spectacular iceberg shapes, we have to be concerned about them too because they could be a sign that climate change is advancing more rapidly than we previously thought.
That should be especially worrying to those who live along the coast. The science of icebergs, especially this particular iceberg, is cool. But let’s not get so distracted by the awesomeness that we forget about the big picture of why we are seeing more and more of them and the threat they pose to our own survival.
Featured Image: Twitter