Freight companies are discovering that Arctic sea ice in September and October is not quite the barrier it appears on the satellite pictures and maps. Perhaps that is especially true this year, with Arctic ice more dispersed than at any time in recent memory. The satellite maps show the Northwest Passage closed, but there are reports of ships passing through, none to my knowledge accompanied by icebreakers. Officially all freight traffic in the Northern Sea Route is guided by Russian icebreakers, but other freight vessels travel farther north to avoid the paperwork, and those get through too.
There are a few explanations for ships passing through areas that seem to be covered in ice. One is that for a ship to get through, it needs a gap in the ice only the size of a ship. You can’t see the ship on the satellite map, so you can’t see the ice at the level of detail that matters to a ship. Another point to consider is that ice comes in a wide range of sizes and forms, some of which are perfectly innocuous. In October, large areas of ocean are covered by what is sometimes called grease ice, and this is no more of a barrier than it sounds. In late summer when weather is calm, a sheet of ice may shrink to a thickness of a tenth of a meter before it shatters. This thin ice may still look just as formidable as a meter-thick sheet of ice, but it is not an obstacle to a ship any more than it is safe for a person to walk on.
I imagine that freight navigators, many on their third or fourth year of Arctic crossing, are gaining experience with the ice and gaining confidence in crossing it. That confidence is not necessarily a good thing, but it does help to explain a continuing increase in Arctic freight traffic, even this year when weather is less favorable.
