As it clatters down a 300-foot ice hole, a small fragment of ice reverberates, producing a series of unusual sounds. First a clang, then the distinct pew of a cartoon gun, and finally a thumping heart beat.
Apart from the strange acoustics, the video of an “ice drop,” shot on a glacier in Antarctica, tells a bigger story about Earth's climate.
Late February brings the end of summer in Antarctica, wrapping up a season of field work for glaciologists.
Peter Neff studies glaciers at the University of Washington. Every few years, he travels to Antarctica to sample ice cores — and occasionally have some fun, too. In 2018, a video of Neff and other scientists dropping small pieces of ice down a glacier bore hole went viral on Twitter.
It sounds pretty neat. Listen to the pew-pew here:
The strange sounds in the video above are explained by the Doppler effect, which describes how waves of sound (or light) change based on the location of an object — in this case, a chunk of ice — relative to its observer.
As the shard travels down the tunnel, it hits its icy sides, producing the clanging noise. The “cartoon gunshot,” as Neff describes it, is the sound of the ice hitting bottom, and the thumping heart beat is the sound wave reverberation as the waves bounce upwards to the surface.
“It’s a really great entryway for people to see what we do,” Neff tells Inverse.
The ice-drop video, which has had more than 10 million views on Twitter, was taken during the 2015-2016 Antarctic summer, which lasts from November to February. The bore hole was on Taylor Glacier, in Antarctica. The data the ice contain are, frankly, as cool if not cooler than the video itself.
Simply put, a glacier is a “stack of snow,” Neff says. And it is “the space between the fingers of snowflakes” — the trapped pockets of air that contain historical information about the Earth's atmosphere — that allows him and other researchers to study the planet's past climate conditions.
“You get a heck of a lot of information, certainly at the resolution of centuries to thousands of years," Neff says. “We can learn a lot from the chemistry of the ice, and also from the air bubbles that are trapped by it.”
Ice cores unlock the past
Ice cores help researchers track marine salts, which reveal how the storm cycle changes season-to-season. They can also determine historical levels of lead, sulfur, and plutonium. The clean ice in Antarctica is particularly good for isolating these historical elements.
“There is so much more ocean in the Southern hemisphere, relative to land,” Neff says. “There are these fantastic records, where we can ask a huge range of environmental questions.”
Those records also cast a spotlight on what people have done to the environment — and how we have cleaned it up. Take lead contamination: Records show a decrease in lead concentrations from 1970s to 1980s as lead was phased out as a component of gasoline.
“That decision, nationally and internationally, to phase out lead use in gasoline, has a clear impact in reducing the levels of lead contamination in glaciers,” Neff says.
This isn't only good news for the fight against pollution, he says. Glaciers are crucial water sources for communities across the world.
The ice offers a way to “point the finger,” Neff says. Through the ice, scientists can identify how humans pollute the environment.
Neff says this sort of finger-pointing can be "productive," and not just a way to cast blame. Ice core data shows how much carbon dioxide and methane has been emitted in the past. It also shows the source of those greenhouse gases. Spoiler alert: We are the source.
In a study published this week in the journal Nature, scientists used ice core data to reveal that humans are adding up to 40 percent more methane to the environment than previously believed — and that non-human methane sources (marshy wetlands produce methane, too) are smaller than expected.
Ice cores definitively show that carbon dioxide concentrations today are about 40 percent higher than pre-industrialization levels. For methane, current levels are more than 200 percent greater, Neff says.
“Ice cores really provide a context for us to place the current rates of change that we’re seeing," he says.
Can viral videos save the planet?
Over the years, Neff has spent a year on the South Pole boring holes in glaciers.
“You get hooked on the experience of going to these amazing places, and being able to sort of represent them back home to people,” he says of his viral videos.
This week, Neff posted a video on Instagram revealing behind-the-scenes shots from one of his research expeditions: a landing plane, researchers setting up camp, and buckets of ice-core segments.
Another recent video features a giant ice razor boring into the ground, 60 meters down. When he shared the video with his 12,500 Instagram followers, Neff was bombarded with a slew of questions:
“How old is the ice?” asked on Instagram commenter. (The ice in the video was from the 1800s, but in places with less snow it can be up to 1,000 years old, Neff replied.)
“How big of a piece can you dig out at a time? And how fast does it drill?” asked another commenter, named burrito___babe. (The researchers drill 1 meter at a time, either 4 or 9.5 inches in diameter, Neff says. And it rotates at 60 rpm — 20 to 30 meters per drill cycle, up to a depth of 240 meters.)
For Neff, it's been eye-opening to see that people are curious, but their understanding of the science varies hugely.
“Because we don’t have a baseline of climate science education in classrooms, there is not a baseline understanding of how dynamic the Earth is," he says.
There is no national curriculum for climate change in the United States, and talking about climate change in schools almost invariably stirs controversy. (Public school teachers in Virginia recently found themselves in hot water after they showed students a video that downplayed how humans are changing the Earth's climate, the Associated Press reported this week.)
Social media, like sharing viral videos of strange ice sounds, also offers a “fascinating and super productive” way for scientists to communicate with each other, Neff says.
As another summer ends in Antarctica, it might be another year before researchers like Neff are drilling into the Antarctic ice. For now, we'll have to settle for some rad videos of glaciologists at work.