A pioneer goes beneath the Doomsday Glacier


The underwater craft Ran lies by the ocean surface, surrounded by ice shelfs.

In a world first, Ran, the Swedish autonomous underwater craft, has ventured under Thwaites Glacier, also known as the Doomsday Glacier. Polar researcher Anna Wåhlin is pleased about the resulting new and exciting data.

Thwaites Glacier in western Antarctic is called the “Doomsday Glacier” because some researchers assert that a climate disaster will begin if the tongue of the glacier gives way. Thwaites is one of the largest glaciers in the world, and if it collapses, a large part of the West Antarctic Peninsula’s ice sheet will disappear, which would lead to a three-metre increase in the sea level.

Anna Wåhlin“We are the first in the world to venture under Thwaites Glacier, and our underwater craft, Ran, came out again with large amounts of exciting data from underneath the ice,” says Anna Wåhlin, a researcher at the Department of Marine Sciences at the University of Gothenburg.

Unique measurements carried out

Among other things, the researchers have been able to measure currents, temperature and chemical properties, such as carbon dioxide content. One of the water samples will also be analysed for DNA. This is being done by Anna Wåhlin’s research colleague, Thomas Dahlgren.

Thomas Dahlgren“DNA analysis provides information about the animal life under the glacier, which in turn tells us how long the glacier has been there – that is, how sensitive it is to climate change,” says Dahlgren, a researcher at the Department of Marine Sciences at the University of Gothenburg.

Ran’s underwater tour lasted for a total of 13 hours. During those hours the underwater craft studied the seabed outside the glacier and measured the ocean currents that passed under the glacier. Ran also travelled a kilometre under the glacier to measure the ocean currents there.

“We were a little nervous before retrieving her because a lot of drift ice had floated into the area being studied. But fortunately, we succeeded in making contact with Ran without problems and could transmit a new position for surfacing in an area with open water. Everyone on board is really elated now. This is a very exciting expedition!”

One of three in the world

The underwater craft makes it possible to study the seabed at great depths and beneath an ice sheet 500 metres thick. These environments previously have been inaccessible to researchers.

Ran in the oceanRan, a seven-metre-long underwater craft, is autonomous. Aside from Sweden, a similar type of craft exists only in the United Kingdom and Australia. Ran can be equipped with a variety of sensors to enable mapping and exploration of marine environments. Through such studies, researchers can follow the evolution of the climate going back thousands of years.

The craft is part of Sweden’s national research infrastructure and can be used by all researchers in Sweden.
Anna Wåhlin with research colleagues in front of RanRan is a specially equipped Hugin AUV (autonomous underwater vehicle) built by Kongsberg, a Norwegian company. The infrastructure receives financing from the Knut and Alice Wallenberg Foundation. The project has been carried out in collaboration with Chalmers University of Technology and Stockholm University.
Facts about Thwaites

Thwaites Glacier is a glacier in Antarctica. It is located in West Antarctica. No country has laid claim to the area. Thwaites Glacier rises 299 metres above sea level. The terrain around Thwaites Glacier is hilly, with the highest point reaching 472 metres above sea level. The area is unpopulated and there are no communities nearby.

Thomas Dahlgren, a researcher at the Department of Marine Sciences at the University of Gothenburg, telephone: +46 (0)31-786 3670, mobile: +46 (0)70-3662042, e-mail:

Photos 1, 2 and 3: Photos by Filip Stedt, Anna Wåhlin, Johan Rolandsson, respectively.
Bottom: Anna Wåhlin with research colleagues in front of Ran.