Antarctica's Blue Melt

A network of cerulean blue meltwater drainage channels has been spotted on the Nivlisen Ice Shelf in Antarctica. The image, acquired by the Operational Land Imager (OLI) on Landsat 9, shows the ice shelf during a phase of strong hydrological connectivity.

According to Geetha Priya Murugesan, a remote sensing scientist, the visibility of the drainage network hints at a deeper vulnerability of the ice shelf. The channels trace preexisting structural weaknesses, including crevasses, that act as "hydraulic pathways" that concentrate meltwater in vulnerable zones.

The summer months are when temperatures creep just above freezing, allowing for expansive networks of seasonal melt ponds and drainage channels to fill with bright blue meltwater. The dark color of the many blue ice areas surrounding the oasis contributes to drainage events by making ice surfaces less reflective, warmer, and thus more prone to summer melting.