This photo shows ogives at the base of Suicide Icefall in Alaska. Ogives are alternating bands of light and dark ice that form ridges and swales at the base of some ice falls. The light ice represents winter ice, when melting is slight, and the dark ice represents summer ice, which gets dirtier due to higher rates of melting. 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.