Scientists Say: Aufeis

This is what forms when water hits seriously cold air

This chunk of aufeis on the North Slope of Alaska was part of a huge wall that formed over the winter. By August, when this photo was taken, the largest chunk left was still about one meter (one yard) tall.

B. Brookshire/SSP

Aufeis (noun, “OWF-ice”)

This is a term from the German language that means “on top of ice” or “toward ice.” This type of ice forms when water emerges from the ground under freezing conditions — such as those in the Arctic. The water is often slightly above freezing, which is why it flows as a liquid. As soon as it hits extremely cold air, however, it turns into a solid. This ice forms a dam or wall. As more water comes out of the ground, it’s stopped by the frozen wall, until it rises over the top of the wall. This overflow then freezes into a new layer atop the first. This happens over and over again. By the time the weather is warm again, there may be aufeis several meters (yards) thick covering and surrounding a spring or river. 

In a sentence

Very tall piles of aufeis may never fully melt during the high Arctic’s short summers.

Follow Eureka! Lab on Twitter

Bethany is the staff writer at Science News for Students. She has a Ph.D. in physiology and pharmacology from Wake Forest University School of Medicine.

More Stories from Science News for Students on Environment