Image of the Week: Ice Routes in Finland Revealed by Landsat

Cloud-free satellite views of Lake Saimaa in Finland are rare in January. But this Landsat 9 scene, captured on January 4th, reveals over 200 miles of winter shipping lanes. The water vapor from 3 large wood pulp factories can be seen on this shoreline. One is located in Lappeenranta, where the ice route begins.

Icebreakers in Finland often keep shipping lanes open through November and December, or until the ice is too thick to break. This route leads north, winding through the coniferous forest of Finland's “Lakeland”. Savonlinna is the home port of at least one local icebreaker, TYRSKY, which appears to be in winter layup as of January 3rd.

Icebreaking activity north along the route is still visible. Here, the route splits near Linnansaari National Park. One branch leads northwest, eventually reaching Varkaus, where another wood mill is visible. The east branch of the route continues on toward Joensuu. Here the route passes through Lake Paasselkä, a deep lake over an ancient impact crater. The frozen lane continues north. This scene ends before the ice route's destination: Joensuu, Finland, but we can see the remainder in a previous capture from 2020.

On January 20th, Landsat 9 captured a new scene, showing that the route has been frozen over until spring. The Landsat archive is used in Finland, and around the world to monitor seasonal changes like these.