The Polar Retrospective – 10 tractors for Antarctica, iceberg calving triggered by tides, and wildfires and polar bears

by Polar Journal AG Team
07/28/2025

The Polar Retrospective looks at recent stories from around the world’s polar regions. This week we take a look at a $17 million contract between the Norwegian Polar Institute and Prinoth, at new insights into the role of ocean tides in triggering iceberg calving in Antarctica, and consequences of wildfires on polar bears.

After equipping itself with Windracers Ultra automatic aircraft for aerial monitoring, the Norwegian Polar Institute is looking for 10 new tracked tractors to pull more equipment across the Antarctic ice cap. Image : Prinoth

The Polar Retrospective is a collaborative effort by the editorial team of polarjournal.net. Each writer chooses a topic they found interesting and important in the past week. The initials at the end of each section indicate the author. We hope you enjoy it.

Norway orders extreme transport vehicles for the Troll station

The Panther XL is an articulated tracked vehicle designed to transport loads on snowy or icy terrain. Image: Prinoth

Crawler vehicle manufacturer Prinoth has been selected by the Norwegian Polar Institute following a call for proposals to equip the Troll station in Antarctica. The $17 million contract covers the delivery of ten Panther XL vehicles, designed for logistics missions on snow and ice. Based in South Tyrol (Italy), Prinoth will rely on its plant in Granby, Quebec, via its Canadian subsidiary specializing in crawler carriers and snow groomers. The vehicles will be delivered with a batch of spare pieces.

Designed for extreme conditions, the Panther XLs feature pneumatic suspension seats, tactile screens, driver assistance software, and cruise control. Their suspended cabs are equipped with heated windows and windshield wipers. Featuring four self-tensioning rubber tracks, they are powered by Caterpillar engines. Each Panther will be able to tow between 10 and 15 sleds, for a total weight of 150 tons. This capacity is essential for supplying the Norwegian station or camps across hundreds of kilometers of ice. “Antarctica demands the best technology,” said Klaus Tonhäuser, president of Prinoth. C.L.

Tides trigger iceberg break-off: New insights into Antarctic calving events

On 23 January 2023, iceberg A-81 – roughly the size of Gran Canaria – broke off from Antarctica’s Brunt Ice Shelf. These Copernicus Sentinel-2 images, captured on 20 and 24 January, show the newly calved iceberg floating in the Weddell Sea. The rift it broke from is known as Chasm-1. Photo: Copernicus Sentinel-2 imagery, contains modified Copernicus Sentinel data 2023

When a giant iceberg breaks off an Antarctic ice shelf, it often comes as a dramatic, seemingly unpredictable event. But new research suggests that the timing of these colossal calving episodes may follow a surprisingly regular rhythm – that of the ocean tides.

A team led by glaciologist Dr. Oliver Marsh from the British Antarctic Survey (BAS) has shown that tides play a key role in when large icebergs detach from Antarctica’s floating ice shelves. Their study, published in Nature Communications, links the calving of iceberg A-81 from the Brunt Ice Shelf in January 2023 directly to the action of spring tides – the strongest tidal forces occurring around full and new moon.

The researchers analysed data from long-term GPS instruments and satellite radar over several years, focusing on the Brunt Ice Shelf and a major rift system called Chasm-1. This crack had been growing slowly for over a decade before A-81 – an iceberg hundreds of square kilometres in size – finally broke away. The team discovered that stress changes and micro-fractures in the ice were closely aligned with tidal cycles. Most notably, key rupture events consistently occurred during spring tides.

“This kind of insight brings us closer to forecasting major ice loss events, and their impact on sea level, with far greater precision,” says Marsh. “Icebergs like A-81 […] account for roughly half of all ice lost from Antarctica each year. Understanding what controls the timing of these events is crucial, because calving not only affects the shape and melt rate of ice shelves, but also their long-term stability.”

The study also highlights the role of atmospheric winds, which can amplify tidal effects on ice shelf dynamics. Together, these findings could help pave the way for short-term prediction models of iceberg calving – something that was previously thought to be near-impossible. J.H.

Wildfires, A Threat to Polar Bears

Known mainly as long-distance roamers of Arctic sea ice, polar bears also rely on land, especially for reproduction. Pregnant females dig dens where they give birth. But in Manitoba, increasingly intense wildfires are putting these critical denning sites at risk. Photo: Julia Hager

In Manitoba, the rising number of wildfires is raising concern among researchers, particularly regarding their impact on polar bear denning areas. As reported by Global News on July 14, Wapusk National Park, located along the Hudson Bay coast, is one of the species’ key breeding grounds. This fragile landscape, where boreal forest meets Arctic tundra, is made up of peatlands, permafrost, and sloped woodland, all ideal conditions for den construction.

But these same features are highly flammable. When fire spreads, it destroys not only trees but also the peat that stabilizes the soil, degrading the quality of the habitat. And with a warming climate and increasingly dry conditions, such fires are expected to become more frequent.

As wildfires continue to rage across Manitoba, active fires are currently being monitored in Wapusk and in the Kaskatamagan Wildlife Management Area. Scientists are mapping these fire zones to anticipate threats and guide future protection efforts. The stakes are high: the western Hudson Bay polar bear population is in decline, and any loss of habitat makes survival more difficult.

The full impact is still uncertain. Some bears may adapt by shifting their denning grounds, while others might return to damaged areas, wasting precious energy. Other species, like caribou, are also vulnerable, particularly during calving season. With the scale and intensity of today’s fires, the question is no longer whether wildlife can adapt, but how much it can endure. M.B.