Alternating bands of light and dark ice that form a series of ridges and swales at the base of some ice falls. The arcuate
bands bend down-glacier due to the faster flow in the center of the glacier than along the sides of the valley walls. The dark
bands represent ice that moved over the fall during the summer season when more melting occurs and form swales. The light bands
represent ice that moved over the fall during the winter season when little or no melting occurs and form ridges.
This photo shows ogives at the base of Suicide Icefall in Alaska. Since glacial flow is faster in the middle of the glacier, the bands
bend down-glacier. The total width of one pair of light and dark bands represents the distance moved by the glacier in a one year period.