Perhaps one of the reasons that people don’t believe in global warming is because it’s not tangible. Meaning, we hear about things like football field size chunks of ice that break off from glaciers, but without being able to understand it in terms of scale, that’s just a number. Sure, a football field is large, but these things can be hard to visibly see, and also comprehend. In fact, New York University oceanographer David Holland indicates, “there’s no real way to determine its size just by looking at it”. Holland’s team has spent a decade observing glacier behavior in Greenland. He gives this example: a distant, dislodged iceberg might look small at first glance, “but then you’ll watch a helicopter fly towards it, and the helicopter will shrink and shrink and shrink and pretty soon it just disappears”.
While I’m not saying that this is the reason for not believing in global warming, but if it can be seen, it’s a little bit harder to believe it to be true. That’s why you probably can’t tell the iceberg in this time-lapse video is remarkable in size. It’s 4 miles wide, half a mile deep, and over a mile long. This is a sizable chunk of Greenland’s Helheim glacier and it’s approximately the size of lower Manhatten. What might be even more impressive is the fact that it weighs somewhere between 10 billion and 14 billion tons. When it broke off from the glacier and landed in the ocean, it only accounted for 3% of the projected ice that Greenland is expected to contribute to the sea in 2018. This all happened in a matter of 30 minutes.
It’s this reason that this time-lapse video is so important to Holland and his team. They are studying calving glaciers in order to understand how this effect could contribute to catastrophic sea-level increases across the globe. Holland states:
“Abrupt sea level change is only going to happen one way, and that’s with some big part of western Antarctica becoming violently unstable due to calving—or not. If not, then there will not be major, abrupt sea level changes.”
In order to understand the importance of this research, you need to understand how, and how fast ice breaks off from glaciers. Glaciers often shed pieces of themselves, but only rarely do researchers capture large events on camera. In the course of his career, Holland has seen it happen just three times.
Based on the video above, you can see that the ice begins to break off from the main part of Helheim. This is known as the tabular iceberg. Almost immediately afterward, the second type of iceberg called a pinnacle iceberg, can be seen calving off toward the right side of the camera. The tabular iceberg is built like a pancake: large, flat, relatively stable. But the pinnacle berg has an aspect ratio like a slice of bread. Tall and skinny, it wants to lie down, so as it separates from the iceberg from the bottom first, its feet shoot forward out from under it as it slides into the sea. From there, sheets of pinnacle icebergs proceed to rip off from the glacier in sequence, driving the tabular iceberg farther down the fjord and breaking into smaller chunks.
This isn’t something that could have been predicted because more modeling and observation is necessary. This video, however, does show us what could and is happening, so this will give researchers the ability to use that for future prediction if nothing else.