With the summer solstice this week, Nicky Gardner and Susanne Kries turn their thoughts to axial tilt and other astronomical matters:
Now here’s a thought. Europeans heading north to cross the Arctic Circle, anxious to catch the mid-summer midnight sun, have to make longer journeys than their parents did.
For the Arctic Circle is slipping north, each year getting a shade closer to the North Pole. Folk in Polcirkeln have a fine appreciation of this point, for the prime asset of this small Swedish village (which takes its very name from the Arctic Circle) is in fact a diminishing asset.
The name Milutin Milankovic is probably not on the tip of your tongue. But the Serbian geophysicist, who died in 1958, holds the key to Polcirkeln’s problem.
Evidently, it was Milankovic who calculated how variations in the tilt of the earth’s axis – a sort of astronomical wobble – cause the Arctic Circle to move around. And it is the Milankovic effect that explains why Polcirkeln’s only claim to fame is sliding off to the north and leaving Polcirkeln stranded. Just now, the Arctic Circle is moving north at a rate of about one meter every month.
Lessons from Polcirkeln
Were we civic leaders in remote Polcirkeln (population about 40 humans and 400 reindeer), we would just have kept quiet about the community’s prime asset having an inconvenient habit of trying to leave town.
But there is a touching honesty about Scandinavians. The good folk in Polcirkeln recognize that visitors are not satisfied with being told that the Arctic Circle is somewhere nearby, but want to see the exact line.
So Polcirkeln has obliged by erecting signs that show where the Arctic Circle was in 2005, where it is now, exactly where it will be in 2015, and other useful indicators.
You’ll pass through Polcirkeln if you take the train along the main route from Boden to Gällivare in Sweden. The train staff very obligingly make an announcement as the train crosses the Arctic Circle.
In truth, it is not a very exciting experience. The forests look much the same on both sides of the Arctic Circle, though we did think that the reindeer looked a little bit perkier north of the line. Curiously, all the reindeer we saw on our most recent journey were walking north – evidently keen to keep up with the Arctic Circle.
Grimsey’s inexorable fate
For a more scenic crossing of the Arctic Circle head to Grimsey, a little island about 40 kilometers north of Iceland (easily reached with a short flight from the mainland with Air Iceland). The entire Icelandic mainland lies south of the Arctic Circle, and the northern part of offshore Grimsey is the only fragment of Icelandic territory which can claim to be in the Arctic.
But go soon. If the Arctic Circle continues to move north the way it is, then in another century or two all of Grimsey will lie south of the Circle. And the number of countries on earth where you can cross the Arctic Circle on foot will have diminished from eight to seven.