Why Icebergs Can Be Blue, Green, or Striped

Icebergs are not always white. Ice with few air bubbles absorbs more of the longer wavelengths of light, so light emerging from within thick ice appears blue. Rare green icebergs often contain marine ice formed from seawater beneath an ice shelf; recent analyses link the green tint in some cases to iron-oxide particles that combine with the ice’s blue color. Dark bands may contain rock debris and dust trapped in the ice. Layers of marine and glacial ice can create contrasting stripes.