Pressure ridge
Encyclopedia
A pressure ridge is an ice formation typically found on large frozen lakes or sea ice
Sea ice
Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

 during the winter. In the most basic sense, a pressure ridge is a long crack in the ice that occurs because of repeated heating and cooling on the surface of the lake.

In cases of extreme cold, ice will shrink in volume like any other solid, opening up cracks in the surface of lakes that are completely frozen over. The cracks quickly fill with water and freeze again, but when the temperature rises later, the ice expands and forces itself upward along the lines of the crack, in much the same fashion that plate tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...

 creates mountain ranges, albeit on a much smaller scale. Pressure ridges can sometimes extend for miles, making an ice road
Ice road
Ice roads are frozen, human-made structures on the surface of bays, rivers, lakes, or seas in the far north. They link dry land, frozen waterways, portages and winter roads, and are usually remade each winter. Ice roads allow temporary transport to areas with no permanent road access...

impassable for truckers hauling freight to far northern locations.

Pressure ridges also develop on lava flows when the solid colder top layer is deformed by movements of the underflowing hotter lava.

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