Under The Ice

The Thwaites Ice Shelf is a thick sheet of packed ice and snow that is larger than the state of Rhode Island (see Frozen World, page 18). The ice shelf forms as ice from the Thwaites Glacier flows off the continent and juts out hundreds of miles over the ocean. Before Icefin, scientists didn’t have a way to see the cold, pitch-black waters beneath Antarctic ice shelves. They had no idea how the ice is melting or what animals could be living in there. But now Schmidt and other scientists are discovering things beneath the ice they’re only beginning to understand.

The Thwaites Ice Shelf is a thick sheet of packed ice and snow that is larger than the state of Rhode Island (see Frozen World, page 18). It forms as ice from the Thwaites Glacier flows off the continent. The ice shelf juts out hundreds of miles over the ocean. Before Icefin, scientists didn’t have a good way to see the cold, pitch-black waters underneath. It was hard to study how the ice is melting or what animals were living beneath it. But now Schmidt and other scientists are starting to learn more.

Ice anemones were first spotted in 2010. A team from the U.S. and New Zealand had traveled to the Ross Ice Shelf, 1,500 kilometers from Thwaites, to test out new drilling technology. They used a jet of hot water to melt a hole 250 meters through the ice shelf, then explored beneath it with an ROV. They found a field of the bizarre anemones covering an area of about 100 square meters.

The ROV hadn’t been designed to collect biological specimens. So the researchers created a makeshift tool using the filter basket from their coffee machine. They caught more than 20 anemones and sent them to Meg Daly, an evolutionary biologist at Ohio State University. Daly found that they were a previously unknown species, most closely related to anemones that burrow into sandy beaches around the world.

But Daly couldn’t explain how boneless anemones burrow into rock-hard ice—or how they survive once they’re there. “If you took a typical sea anemone and put it in the freezer, it would die,” says Daly. “How does an ice anemone not freeze its little butt off?”

Ice anemones were first spotted in 2010. A team from the U.S. and New Zealand had traveled to the Ross Ice Shelf, 1,500 kilometers from Thwaites. They were there to test out new drilling technology. They used a jet of hot water to melt a hole 250 meters through the ice shelf. When they explored beneath it with an ROV, they found a field of the anemones. The animals covered an area of about 100 square meters. 

The ROV hadn’t been designed to collect animal specimens. So the researchers created a net using a part from their coffee machine. They used it to catch more than 20 anemones. They sent them to Meg Daly, a biologist at Ohio State University. Daly realized that the anemones were a previously unknown species. They were related to anemones that burrow into sandy beaches around the world.

But Daly couldn’t explain how soft, squishy anemones burrow into rock-hard ice. She also didn’t understand how they survive the freezing temperatures. “If you took a typical sea anemone and put it in the freezer, it would die,” says Daly. “How does an ice anemone not freeze its little butt off?”

These mysterious ice anemones are only a small part of this underwater ecosystem. But studying it is no easy feat. Ice shelves are hundreds of meters thick, and bringing drilling equipment to remote Antarctica is costly and difficult. The larger the hole scientists need to drill, the more expensive and complicated the expedition will be.

To help, Schmidt’s team has spent nearly 10 years developing and testing Icefin. The torpedo-shaped robot can fit down a hole just 25 centimeters across. It can carry more than a dozen sensors, including cameras, thermometers, and instruments that analyze water chemistry. The 3.5-meter-long robot can be taken apart and packed in separate pieces to make it easier to transport.

Icefin was first deployed in 2017, and has only had three summer research seasons to explore. There’s still a lot more it can help us learn about the mysterious world beneath Antarctic ice shelves. But Schmidt also has another goal: to look for life in other parts of the solar system. Jupiter’s moon Europa, for example, is covered in thick ice with an ocean underneath it that could potentially support life. Exploring with Icefin “allows us to get ready for what we might do 50 to 100 years from now in places like Europa,” says Schmidt.

In the meantime, Thwaites and Antarctica’s other ice shelves are already changing rapidly. Climate change is warming the waters around Antarctica, melting the floating ice from below. That’s why scientists like Schmidt and the rest of the Icefin team are racing to learn all they can—before it’s too late. “People come together and work really hard together,” says Schmidt. “We even had Christmas dinner and celebrated New Year’s Eve out there.”

Ice anemones are only a small part of this underwater ecosystem. But studying it is no easy feat. Ice shelves are hundreds of meters thick, and bringing drilling equipment to Antarctica is expensive and difficult. The larger the hole scientists need to drill, the more complicated the process will be.

To help, Schmidt’s team has spent nearly 10 years working on Icefin. The torpedo-shaped robot is 3.5 meters long and can fit down a hole just 25 centimeters across. It can carry more than a dozen scientific sensors, including cameras and thermometers. It can also be taken apart into separate pieces to make it easier to transport.

Schmidt’s team first deployed Icefin in 2017. They have used it for three summer research seasons so far. It can still help scientists learn a lot about the mysterious world beneath Antarctic ice shelves. But Schmidt also has another goal: to look for life in other parts of the solar system. For example, Jupiter’s moon Europa is covered in thick ice. The ocean underneath it could potentially support life. Exploring with Icefin is practice for exploring places like Europa, says Schmidt. “It allows us to get ready for what we might do 50 to 100 years from now,” she says.

In the meantime, ice shelves like Thwaites are already changing. Climate change is warming the waters around Antarctica, melting the floating ice from below. That’s why scientists like Schmidt and the rest of the Icefin team are racing to learn all they can before it’s too late. “People come together and work really hard together,” says Schmidt. “We even had Christmas dinner and celebrated New Year’s Eve out there.”