In late June, one of the most powerful icebreakers in the world encountered such extraordinarily thick ice on-route to the North Pole (with a polar bear specialist and deep-pocketed, Attenborough-class tourists onboard) that it took a day and a half longer than expected to get there. A few weeks later, in mid-July, a Norwegian icebreaker also bound for the North Pole (with scientific researchers on board) was forced to turn back north of Svalbard when it unexpectedly encountered impenetrable pack ice.

Apparently, the ice charts the Norwegian captain consulted showed ‘first year ice‘ – ice that formed the previous fall, defined as less than 2 m thick (6.6 ft) – which is often much broken up by early summer. However, what he and his Russian colleague came up against was consolidated first year pack ice up to 3 m thick (about 10 ft). Such thick first year ice was not just unexpected but by definition, should have been impossible.

Ice charts for the last few years that estimate actual ice thickness (rather than age) show ice >2 m thick east and/or just north of Svalbard and around the North Poie is not unusual at this time of year. This suggests that the propensity of navigational charts to use ice ‘age’ (e.g. first year vs. multi-year) to describe ice conditions could explain the Norwegian captain getting caught off-guard by exceptionally thick first year ice. It also provides an explanation for why the polar bear specialist onboard the Russian icebreaker later failed to explain that first year ice of such shocking thickness was truly extraordinary, not just a bit thicker than usual.

’50 Years of Victory’ voyage, 15-28 June

Polar bear specialist Thea Bechshoft, staff scientist for Polar Bears International, had a hard time explaining the astonishingly thick sea ice they were experiencing to wealthy tourists on a two-week journey aboard a Russian icebreaker bound for the North Pole from Murmansk – you could book a berth yourself next year at a cost of ~US$30,000-90,000 per person (not counting the cost of getting to Helsinki and back).

In her 24 July 2019 essay for PBI, she didn’t bother to mention just how thick the pack ice really it was and that it was first year ice that should have been less than 2 m thick. She left out the fact that the massive nuclear-powered ’50 Years of Victory’ was capable of plowing at some speed through ice 2.5m (9.2 ft) thick, which seriously downplayed the significance of the powerful ship struggling to make headway. Although Bechshoft does not say where the thick ice was first encountered, it is almost certainly while the ship was still in the southern Barents Sea between Svalbard and Franz Josef Land (because such thick ice near the North Pole would not have been surprising):

Earlier this summer, as I leaned over the railing on the bow of our ship for a better view of the sea ice below, I heard a fellow traveler exclaim, with awe in his voice: “That’s some serious ice!” He was, in fact, so fascinated by the ice that he repeated this sentiment a few times. I found myself in the odd position of simultaneously agreeing and disagreeing with him. If we only looked at the area we were passing through during this particular month and year, what we saw was indeed really impressive sea ice. In fact, the sea ice we encountered was thick enough that reaching our destination—the geographic North Pole—took roughly 1.5 days longer than we’d expected. The exchange took place during a Quark Expedition trip that I was privileged to join, traveling on the nuclear icebreaker “50 Years of Victory” on a voyage from Murmansk in Russia to the North Pole. While much of my time was spent sharing science and conservation information with passengers, I also used this unique opportunity to spend a lot of time observing the sea ice as we moved through it on our way to the highest of the High Arctic, 90° North. “50 Years of Victory” is a powerful ship of 75,000 horsepower total and the highest possible ice rating, but even she had to back up and find alternative routes through the ice every now and then. However, if we look at the bigger perspective as provided to us by satellite data, the status of the Arctic sea ice as a whole is in fact very far from impressive: not only was the Arctic sea ice extent this summer the second lowest on record, the ice is also getting progressively thinner. … Just like my fellow passenger, most of us often have a tendency to judge the general state of things on specific singular events, especially if we experienced those events in person. This is why satellite data and other historical sea ice records are incredibly important in order for us to identify the long-term trends of what is happening to the Arctic sea ice extent and thickness. Without long-term continuous, impartial monitoring, we may become oblivious to the critical changes caused to the Arctic ecosystem by our warming climate. This “blindness” to change is also known as shifting baseline syndrome: Chronic, slowly degrading changes in ecosystems can be incredibly difficult for us to notice if they happen over a period of multiple decades. This is true for the disappearance of the Arctic sea ice, but also for example for the dwindling number of insects found around the globe. [my bold]

Crown Prince Haakon voyage 15 July

The Norwegian icebreaker ‘Kronprins Haakon‘ (Crown Prince Haakon), also bound for the North Pole, had to turn back on 15 July due to sea ice up to 3 m thick (almost 10 ft). Based on a Norwegian news report, the blog Ice Age Now reported 16 July 2019:

Thick one-year ice combined with large batches of multi-year ice joined together into powerful helmets, and several of these are impenetrable to us, said Captain Johnny Peder Hansen. The ice is up to three meters (almost 10 feet) thick in the middle of July, and not even the researchers’ long special-purpose chainsaws were able to penetrate the ice. … “In the middle of July we see few signs of thawing and that spring has come. We had expected more melting and that the ice was more disintegrating, ”says Captain Hansen, who for several decades has worked on various vessels in the Arctic. [my bold]

Sea ice thickness charts

While it may be that ice extent this year has declined to low levels relative to 1979 – as it has done since 2007 without any acceleration – the ice chart below issued by the Danish Meteorological Institute (for 19 June and 15 July, dates relevant to the icebreaker journeys discussed above) shows thick ice greater than 2m (turquois-green, green and yellow) extending from Svalbard in the Barents Sea to the North Pole (900N). If ice shown on these charts as ‘1.5-3.5’ m thick appeared as ‘first year ice’ on navigational charts or reports (such as issued by the North American Ice Service, summer 2019 outlook here), the extreme thickness would have presented a surprising navigational challenge to the icebreaker captains.

The icebreaker ‘50 Years of Victory‘ out of Murmansk struggled through thick ice (above chart) along a route between Svalbard and the Franz Josef Land archipelago (see route map below) and reached the geographic North Pole a day and a half later than scheduled on the 19th or 20th of June. The ship stopped at Franz Josef Land on the return trip to Murmansk, where many polar bears were seen.

Several weeks later, the Norwegian icebreaker ‘Crown Prince Haakon‘ traveled through thick first year ice north of the west coast of the Svalbard archipelago (ice chart below) towards the North Pole but had to turn back on 15th July.

While Bechshoft makes it sound like thick ice is a rare occurance in June in the Barents Sea and around the North Pole, in fact ice of such thickness has been relatively common (especially near the North Pole) in recent years (see charts below). For example, in 2015 (see chart below), most of the ice in the Barents Sea between Svalbard and Franz Josef Land was even thicker than this year at mid-June:

Really, only 2012 had truly wide expanses of thin first year ice in the Barents Sea that extended towards the North Pole:

However, first year ice that’s 3 m thick is indeed a rare occurance, especially in the southern Barents Sea.

In other words, the suggestion that this early summer’s exceptionally thick ice in the eastern Arctic and Barents Sea is so rare as to qualify as a “singular” event is nonsense but it is rare – and may well be significant – to encounter such exceptionally thick first year ice in the southern Barents Sea and just north of Svalbard. The propensity of navigational charts to use ice age rather than ice thickness to describe ice conditions almost certainly explains the Norwegian icebreaker captain getting caught off-guard by exceptionally thick first year ice because first year ice 3 m thick simply should not exist.