Could A Small But Rapidly Disintegrating Antarctic Glacier Climate Change Danger Signal?

Hektoria glacier in Antarctica was largely reduced
to debris ice after it abruptly retreated at a record pace.
Photo by Naomi Ochwat

When you think of glaciers, and how they melt, you probably picture a slow, drip, drip, and maybe a little stream or river running out of the edge of it. 

You'd think it would take years, even decades for most of a glacier to wilt or disappear under pressure from climate change. 

But one glacier in Antarctica, the Hektoria Glacier, is breaking speed records for eroding, says a team of researchers led by Naomi Ochwat, a University of Colorado glaciologist.

Per the Washington Post;

"More than five miles of glacial ice in Antarctica vanished in only two months, retreating 10 times as fast as the previous record, with possible implications for the stability of other glaciers and the pace of sea-level rise on a warming planet."

 Hektoria Glacier is on the eastern side of the Antarctic Peninsula, and is pretty small compared to most glaciers in Antarctica. It'sabout the size of Philadelphia.  The peninsula is that finger of land that comes off Antarctica and points toward South America, like a frigid finger seeking out warmth away from the Antarctic ice cap. 

But the fact that it retreated so fast makes scientists wonder about other, much bigger glaciers. Can they, too, disintegrate as fast as Hektoria? Was Hektoria a canary in a coal mine, or since this is Antarctica, a penguin in a coal mine?

That would be a problem, as glaciers that are on land add to global sea level rise as they melt. A rapid melt might accelerate those rising sea levels beyond what many scientists already expect.

 It's already bad enough, as storms are increasingly bringing sometimes serious storm surges to coastlines. We also already have "sunny day floods" when tides are particularly high when the pull of the moon is just right. 

If all of Antarctica's ice melted, sea levels would rise by about 190 feet. Of course, much of Antarctica's ice is here to stay, but even if a small percentage its glaciers go bye-bye, sea coasts worldwide would be in big, big trouble. 

Here's how the Hektoria Glacier disintegrated, as WaPo tells us

"Heckoria is a tidewater glacier, meaning it flows across land before ending in the sea. After rising temperatures reduced the amount of sea ice in the bay abutting the glacier, waves broke down ice fastened to the coastline that had protected Hektoria. 

And, without that buffer, the floating end of the glacier began cracking and shedding icebergs into the ocean."

Once the glacier lost its floating portion, the rest of it thinned, and a gently sloping plain underneath the glacier let ocean water to seep in. The ice bobbed up with the water getting beneath it, so it broke up quickly. 

As usual with these things, there's disagreement over whether this is a one-off or if many other glaciers are on the brink of collapsing. 

There's something called the grounding zone. It's the spot beneath the glacier's ice where the ground ends and it starts to float on ocean water. 

The scientists looking into this don't exactly know where the Hektoria Glacier grounding zone is. If the grounding zone is further inland than the researchers figure, the glacier ice was already on water, making it more prone to breaking up. 

Ochwat said seismic sensors detected a bunch of little earthquakes when Hektoria was in retreat and falling apart. That probably means the ice was resting on bedrock. "Because that ice is touching the Earth, we get earthquakes," she said. 

The Washington Post said Ochwat is going to look at other Antarctic glaciers to see if they're also on slick, shallow beds that are vulnerable to fast retreats. 

The reason that people are worried about other glaciers is, of course, climate change. 

As CNN tells us:

"Hektoria's retreat was heavily influenced by climate change (Ockwat) said. The loss of sea ice in the ocean next to Hektoria, believed to have been driven by ocean warmth, allowed wave swells to reach the fast ice and break it up, leaving the glacier exposed to ocean forces."

As sea ice continues to decline due to climate change, more glaciers might be poised to fall apart like Hektoria did. 

Hektoria is "a smaller cousin to some truly gigantic - I mean the size of the island of Britain - glaciers in Antarctica that could conceivably go through the same process, as this whole evolution of the ice sheets on Earth evolves with global warming," Bethan Davies, a glacial geologist at Newcastle University told CNN. 

 There's another glacier in Antarctica, the Thwaites Glacier, which some overwroughtly call the "Doomsday Glacier" contributes 4% of overall sea level rise. Another one the Pine Island Glacier is Antarctica's fastest melting glacier. 

The bottom line: Antarctica makes climatologists nervous, and this new knowledge isn't exactly Zoloft  for scientist's climate change anxiety. 

We need to make sure scientists keep studying the hell out of Antarctica and its ice and its melt rate. What goes on in Antarctica doesn't stay in Antarctica.