Norwegians call it Sulitjelmaisen, after the massif and the mining village below. Swedes call it Salajekna. In Lule Sami it is Sállajiegŋa — the name the other two are ultimately borrowed from, since almost every deep-map name in this country came out of Sami first and was written down later by clerks who heard it approximately. The Norwegian portion sits in Fauske Municipality in Nordland, about forty kilometres east of the town of Fauske. The Swedish portion straddles the boundary between Arjeplog and Jokkmokk municipalities in Norrbotten County, so the ice is simultaneously in two countries, three municipalities and at least three languages. Nothing about the surface indicates any of this. It is a white plateau with a survey line drawn across it on paper.

The glacier's highest ice reaches 1,680 metres above sea level and its lowest tongue comes down to 830 — an 850-metre span, and around 300 metres of thickness at its deepest. It drapes the flanks of a massif whose summit, Suliskongen, stands higher still at 1,908 metres, so the ice is not a cap sitting on top of the mountains so much as a filling poured into everything between them. Alongside it lies Stuorrajekna, whose Sami name simply means 'big glacier' — the local vocabulary for ice in this range is extensive and matter-of-fact. Just south of the Sulitjelma Glacier, the lake Låmivatnet catches meltwater at the foot of the slope, which is where a glacier's accounting becomes visible: what the ice loses in a season, the lake receives.

Near the glacier front, Stockholm University runs an automatic weather station. It is a small installation in an empty place, and it exists because a glacier is one of the few landscape features that keeps its own records. Snowfall, temperature, wind and radiation at the front are the raw inputs; what comes out is a running measurement of whether the ice is gaining or losing, year on year. The answer here has been consistent and unwelcome. The Sulitjelma Glacier has retreated in recent years, in step with the other temperate icecaps of northern Scandinavia — Blåmannsisen a short way north has lost roughly eight square kilometres since 1961, and this ice is on the same trajectory. Anyone who wants to know what a warming Arctic looks like at the scale of a single valley can read it off a mast bolted to bedrock at 67 degrees north.

Downhill and west, the village of Sulitjelma sits at 140 metres above sea level on the shore of Langvatnet, about 470 people in a place that once held nearly 3,000. It grew because of copper and pyrite in the rock and shrank when the mines closed in 1991, and it lives now within sight of the glacier that shares its name — or the name they both took from the massif above. There is a symmetry to it that nobody planned. Sulitjelma the village went from almost nothing to an industrial town and most of the way back inside a hundred years. Sulitjelma the glacier is doing something similar, over a longer span and without any decision being made about it. Both are shaped by forces set in motion somewhere else entirely.