A massive blue "melt pond" has been spotted on an Arctic glacier in southeastern Alaska, according to a 2014 NASA photo. This phenomenon is becoming increasingly common due to climate change and is accelerating the rate of ice loss across the region. Melt ponds form when the ice thaws from warmth and water pools in depressions within the ice. While these features have always been present in the Arctic, their increased appearance is concerning for researchers as they absorb more sunlight than snow and ice, causing them to warm up and melt more ice.
Source: https://www.livescience.com/planet-earth/arctic/earth-from-space-massive-blue-melt-pond-in-arctic-glacier-is-an-eerie-sign-of-things-to-come