Oh, tjern is a good word. I forgot about that, lol. I think I personally would call the body of water in this image a tjern.

I would call it “vatn” or “vann” (the joys of two written languages), which literally translates to “water”. Usually they don’t have names, but if they are close to a hiking route they are normally referred to by the name of the mountain top + “vatnet”. Sometimes they are close to a mountain cabin and the area will have a name, usually a family name from “old times”, and the water will be referred to by the same name as the area.

I hope it make sense. I wanted to use lots of Norwegian words that I can’t translate on the fly.