Researcher Drops Block of Ice Into 450-Ft-Deep Hole in Antarctica — Hears an Eerie Sound From Below

Usually, when an ice cube crashes, collides, and grinds against another ice cube, it produces sounds like a thud, a clang, or a clunk. But when John Andrew Higgins (@blueicehiggins) dropped down a 9-inch ice core down a 450-foot borehole, which is approximately the height of the Great Pyramid of Giza, an unusually high-pitched sound reverberated and bounced back towards him. Of the millions of people who viewed this viral footage, many likened the sound to “ricocheting laser beams” and “Star Wars laser gun battle.”

This short video was recorded during his 2019 expedition to Antarctica to extract 2 million-year-old ice cores, according to a university press release. Higgins, who’s a paleoclimate professor and isotope geochemist at Princeton University, was living in tents in Allan Hills, Antarctica, at this time. He and his colleagues were monitoring gas bubbles trapped in the ice cores to collect samples of carbon dioxide, methane, and other gases that could provide valuable information about the environmental conditions and history of the ice sheet.

In this footage, the hands of a person, most likely Higgins himself, appear to be holding a thick chunk of ice above a tunnel of blue ice drilled deep into a sunlit snowscape. The person drops the ice chunk inside the hole. After a narrow gap of a few moments, the dropped chunk echoes some sounds back to the surface. Unlike a typical thud or plonk, the sound seems to resemble a futuristic zap like the ones made by those cartoon spaceship engines or robotic devices, a flurry of sparks of a glitch in electronics.

The strange sound made billions of people curious, and they concocted even stranger stories about how it was produced down below. “Sounds like Yosemite Sam going on a rampage,” wrote @absofruitleenot. @paulathrall likened it to the “sound of bullets.” @dandarepotf commented, “Sounds like a shoot-out at the bottle bank.”

Enthused by people’s intense curiosity, Higgins’s Antarctic colleague and future University of Minnesota ecology professor Peter Neff (@icy_pete) posted a follow-up video from Law Dome, Antarctica, with an explanation of this mysterious sound. Neff is a glaciologist with vast experience in drilling holes and dropping ice chunks down. In 2018, he recorded a similar sound of an ice chunk falling down a 295-foot drill hole. He shared that their research team in Antarctica works on drilling ice cores “that can be up to 800,000 years old,” mainly “to draw out ancient air” trapped in the ice. From these time capsules of ancient air, they can evaluate the air quality and climatic changes over time, just like in tree rings.

After drilling these cylindrical tunnels into the blue ice, they scoop out ice cores of various shapes and sizes. But why do they sound so weird? “The logical human thing to do is throw some ice down a deep hole,” Neff explained. He said that there are two factors at play: the Doppler effect and the way sound waves move through the hole.

“The first thing you hear as the ice is falling is the pitch of the sound changing. That’s the Doppler effect. Then, when the ice hits the bottom of the bore hole, the sound doesn’t only come straight up—the sound waves start to bounce off the sides of the hole. That’s why you hear this plink! with sort of a heartbeat sound afterwards,” said Neff. Meanwhile, people are saying that they can’t stop listening to this electronic pew-like sound, probably because, as Neff said, “it never gets old.”