By Fabio Giannino, Global Product Training Manager, IDS GeoRadar and all images are credited to Matthieu Tordeur and Dr. Heïdi Sevestre.
Polar science projects have traditionally relied on tractors and snowmobiles that burn huge amounts of fuel, so research into climate change has itself carried an environmental cost. The approach has also left much of Antarctica unmapped, because collecting accurate radar data means contending with extreme cold, rough terrain and a landscape that offers no easy way in.
Yet scientists urgently need to understand how Antarctica is responding to climate change so they can better predict consequences like rising sea levels.
To look beneath the surface, a new approach was needed. With UNESCO for the Decade of Action for Cryospheric Sciences, glaciologist Dr Heïdi Sevestre and polar explorer Matthieu Tordeur crossed the continent with two ground-penetrating radars (GPR). Powered only by wind and solar energy, the pair completed the first radar transect by kite-ski for polar science.
The expedition delivered the first dataset from some of Antarctica’s most remote regions, and showed that polar science can be sustainable without compromising the data needed to understand changing ice levels and the environment.
The challenges of scanning a frozen continent
The set-up on the ice, including the GPR, provided by IDS GeoRadar, and a GNSS receiver from Leica Geosystems, in action despite freezing temperatures.
The team set out to map both ancient and recent ice layers, record snow accumulation, and harmonize existing data from the few regions that had already been mapped to create a single picture.
Achieving the goals of the expedition meant battling extreme cold. Temperatures dropped as low as -50°C, beyond anything a standard freezer reaches.
“The environment was the biggest challenge,” explains Dr Heïdi Sevestre, “It’s a different planet, a different universe. The biting cold can suck the energy out of everything, especially the batteries. Each night, we slept with the batteries in our sleeping bags to keep them warm.
We were also battling unpredictable winds. It was either too violent, or if the wind dropped and conditions were too calm, it was impossible to take off on our skis. This was a huge challenge because the speed of travel is really important. Moving too fast or too slow can compromise the quality of the radar measurements.”
Adding to this, Antarctica’s terrain is made up of metre-high ice dunes, which made skiing difficult; the team had to tow around 200 kg of equipment across the bumpy surface.
All this left little room for error. With so much attention focused on survival and avoiding falls and frostbite, the time available for research was precious. Success depended on careful planning and the right technology that could survive the conditions and deliver accurate data.
Mapping Antarctica using kites, skis and ground penetrating radar
To tackle the wind and the cold, the team used the complex conditions to their advantage. Kite skiing offered a way to tow the radar on sleds with no fuel and no generator.
“We used kites of different sizes for different wind speeds to help us travel,” explains Sevestre. “You don’t want to be skiing too fast, so it was the best way to collect the data. Even when a kite was punctured and had holes, it was still repairable.”
The radar had to be just as resilient. “Ground-penetrating radar is usually used for utility detection, but the compact surface system turned out to be robust and perfect for icy conditions,” says Sevestre. “It works a bit like sonar, scanning whatever is beneath your feet. We used a shallow radar to scan the upper 40 metres of the Antarctic ice sheet. Almost everything broke during our journey but the radar. It remained reliable from start to finish, and that’s what let us capture the data we came for.”
The contents towed on the sled: the Chaser XR GPR, Leica GS16 GNSS receiver and Panasonic FZ-55 semi-rugged laptop.
Rather than the wheel-based trigger common in utility surveys, which would struggle on snow, measurements were triggered by GPS, with positioning from a GNSS receiver. The team used a surface shallow radar, which they checked every two hours for any faults or errors. A second radar worked alongside it to reveal deeper ice layers and map the bedrock, scanning up to two kilometers below the surface.
Over roughly 80 days and 4,000 kilometers of travel, both radars collected more than 1,500 kilometers of linear data, revealing for the first time what had previously been invisible beneath the ice.
From the ice to the inbox: processing the scanning data
When undertaking a project like this in a remote location, data is usually processed back in the office. But this was the first expedition in Antarctica with an internet connection, meaning the expedition team could store the data in the cloud and send it to the office in daily batches.
Back at the IDS GeoRadar office in Italy, each batch arrived in near real-time, where the team could monitor the equipment and troubleshoot remotely. Sevestre and Tordeur’s position was also updated in Google Earth every day.
“You can do science differently today,” says Sevestre. “It’s like being an astronaut with a Houston course-correcting you on the way. There’s a bigger team supporting us from miles away, and it felt comforting.”
Lenin’s bust at the Southern Pole of Inaccessibility, which fewer people have reached than the moon.
Some of the most valuable data came from the most remote places. After 42 days and nearly 1,800 kilometers of kite-skiing, Sevestre and Tordeur arrived at the Southern Pole of Inaccessibility, historically calculated as the point in Antarctica farthest from any coastline. A bust of Lenin still overlooks a Soviet scientific base built in 1958, now buried beneath the snow.
“This is the data I’m most excited about,” says Sevestre. “The scans, once processed, revealed the base buried beneath the ice, and showed us how much snow had fallen here since the 1950s, when the statue was erected.”
Radar scans around Lenin’s bust reveal the buried remains of the 1958 Soviet base.
“As the radar was triggered by GPS, every scan is tied to an exact position. Once the office team processes this data completely, we should be able to reconstruct the buried Russian station.”
The expedition has produced a dataset that gives scientists a clearer picture of Antarctica’s past and future. With the data due to be made openly available, researchers around the world will be able to use it to understand and protect the continent’s biodiversity and to predict changing sea levels.
“When we were in Antarctica, we realised just how connected everything is,” explains Sevestre. “The changes happening at the poles don’t stay here. They affect sea levels, weather patterns, ecosystems and communities all across the globe.”
The expedition also sets a precedent for how GPR technology and sustainable ways of working can help map the planet’s most remote environments, where traditional methods struggle and very little data exists. Learn more about the project: underantarctica.com
