A field of pancake ice in the Weddell Sea, Antarctica. These small discs of sea ice form under turbulent growth conditions, when wind and waves agitate the ocean surface. Aggregations of ice crystals constantly collide, leading to the characteristic raised edges. Further south, these discs stick onto each other, forming discs of up to several meters in diameter. Eventually, the entire ocean is covered by pancakes, which subsequently become hidden under snow.
Mario Hoppmann (distributed via imaggeo.egu.eu)