Why does this Antarctic glacier seem to bleed?

At the foot of Taylor Glacier, salt water produces a red flow over ice and soil. The place was named Blood Falls. The image suggests blood, while the explanation is in a very different chemistry.

Water from the subglacial system contains iron. Microscopic analyses have identified tiny spheres rich in this element. The results link coloring to iron oxidation and the formation of these particles when exposed to air.

The detail counts: these particles do not have an orderly crystalline structure, which complicates their identification by certain methods. The strangeness of the landscape is therefore understood by looking at what is almost infinitely smaller than it. A huge red trace tells the story of tiny transformations.