Greenpeace in Greenland
Holes containing cryocronite deposits visible in the bed of a melt water lake on the Petermann glacier in north Greenland. The surface of the glacier is covered with pot holes like these, which are often perfectly circular to the eye. The black granular cryocronite accelerates melting because the darker part of the spectrum lowers the albedo or reflectance of the usually white ice. A combination of these darker deposits, warmer melt water, the sun and the wind conspire to make these intriguingly geometric pot-holes in the ice. The sizes typically vary between 3cm and 30 cm in diameter and are between 3 and 500 cm deep. A team of three scientists are on board the Arctic Sunrise during the 1st leg of Greenpeace's 3 month long Arctic Impacts expedition around Greenland, to document the effects of climate change on the Arctic environment ahead of the Copenhagen summit which will be held in December 2009.