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.
A polar bear on hummocked sea ice in Franz Josef Land. Photo by Michael Hambrey, date not specified but estimated based on tour dates to be 22 or 23 June 2019.
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.
Posted in Advocacy, Sea ice habitat
Tagged Barents Sea, extent, first year ice, Franz Josef Land, ice age, icebreaker, North Pole, polar bear, sea ice, Svalbard, thick ice, thin ice
A cross-Arctic comparison shows that the US has been the most aggressive in designating polar bears and their main prey species as ‘threatened with extinction’ due to the predicted effects of human-caused (“anthropogenic”) global warming (AGW), even though the US has the least amount of sea ice habit of all circumpolar nations.
I’ve made a chart listing the conservation status of these species across all Arctic nations (Canada, Russia, Norway, Denmark (for Greenland) and the USA), as well as the one international body that considers the conservation status of all species (International Union for Conservation of Nature, IUCN).
Oddly, the IUCN considers the polar bear vulnerable due to future threats from predicted sea ice losses but not ringed seals or bearded seals. This situation highlights the capricious nature of the use of “future threats” (almost exclusively based on predictions of AGW) as a valid criteria for evaluating the conservation status of Arctic marine mammals. It also suggests why the IUCN has tightened considerably its rules regarding this practice.
Posted in Conservation Status, Summary
Tagged AGW, Arctic nations, arctic seals, bearded seal, conservation, global warming, IUCN, North Pole, polar bear, Polar Bear Specialist Group, ringed seal, threatened with extinction, walrus
To counter the misleading ploy used by the Sunday Times — of implying polar bears are in peril because of recent changes in Arctic sea ice (Sunday Times & The Australian, 21/22 Sept. 2014 Arctic ice cap in a ‘death spiral’) — I’ll go over again why the polar bear as a species is not threatened by declines in summer sea ice or even winter ice that is predominantly “thin” (first year) ice.
Graphic above from the Sunday Times, September 21, 2014
Posted in Conservation Status, Sea ice habitat, Summary
Tagged Arctic ice cap, arctic sea ice, Chukchi Sea, death spiral, denning females, evidence, first year ice, ice thickness, ice-free Arctic, Mark Serreze, North Pole, Peter Wadhams, polar bear, sea ice extent, thin sea ice
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