Racing Stripes
Earth Resources Observation and Science (EROS) Center - Earthshots
Glaciers move slowly, but Bear Glacier seems to have racing stripes. Glaciers pick up dirt and debris from the rocks they pass. They deposit that material in accumulations called moraines. A lateral moraine is the material on the sides of a glacier.
Two glaciers flowing together form a medial moraine in the middle where they join and show up as those dark stripes. When a glacier has a medial moraine, it’s made up of more than one ice flow.