Glacier Detective

A small plan flies over the frozen expanse of Antarctica. Below it is Thwaites, one of the continent’s largest glaciers. The plane, which is equipped with skis on the bottom, lands on the large, slow-moving body of ice. Sridhar Anandakrishnan and his team of scientists hop out and start to set up camp. The plane takes off, leaving the scientists alone on the glacier. This is where they will live for the next three months.

Anandakrishnan is a glaciologist at Pennsylvania State University. He’s working to understand how quickly glaciers like Thwaites are melting in response to climate change. To gather data, he must travel to cold, remote places. In the field, there’s no way to get supplies, so the scientists must bring everything they need. “We cook our own food, melt snow to make water, and fix our snowmobiles if they break,” says Anandakrishnan. He spoke with Science World about the challenges of studying glaciers and what he’s learning about Antarctica’s rapidly changing environment.

When I was an engineering graduate student at the University of Wisconsin, I took a job with the Department of Geology fixing equipment being sent to Antarctica. Later, I was asked to go to Antarctica to install the instruments. It sounded like a fun adventure, so I went. I became so entranced and excited about the place and the science that I changed my degree program from engineering to geophysics [the physics of Earth] so I could study glaciers.

Antarctica has thousands of glaciers that are melting into the ocean. When all is well, the amount of water leaving a glacier is about the same as the amount of snow that falls on it. But climate change is causing temperatures in Antarctica to rise. Glaciers are melting into the oceans faster than their ice is being replenished, resulting in sea-level rise. Rising seas will be devastating for coastal areas. Storms will push seawater farther inland, increasing flooding. The more we learn about glaciers, the better we can prepare for the future.

Many glaciers flow into ice shelves. These floating sheets of ice help block glaciers from reaching the ocean. But the ice shelf next to Thwaites is melting and shrinking, so the glacier is directly impacted by warming ocean temperatures. It’s also one of the largest glaciers in the world—about the size of Florida. So it moves an enormous amount of ice to the ocean.

Over the next 100 years, melted ice from Thwaites could raise sea level by as much as 70 centimeters (2 feet). Nearly 150 scientists in the U.S. and U.K. are building a computer model to predict what will happen to Thwaites if the ocean warms by different amounts: 0.5, 1, or 2°C. To make an accurate model, we need to know how thick and wide a glacier is and how fast it’s flowing. I’ve been gathering data by sending radio and sound waves down through the ice. When the waves reach the rock beneath the glacier, they reflect back to the surface. Changes in the shape of the waves we detect tell us about the glacier’s thickness.

Hopefully, we’ll learn how the glacier will behave in the future. Then we can say how much sea level will rise if we keep warming the globe at the rate we are now. I hope we can gather enough evidence to influence policy makers to limit carbon dioxide emissions. This greenhouse gas, which traps heat in Earth’s atmosphere, is one of the main contributors to climate change.

Math and physics are central to the work I do, so it’s important to study those areas. Our field also needs more women and people of diverse backgrounds. I’m a city kid and a person of color. If you can picture yourself doing this type of work—regardless of where you come from—you can make it happen.