This enigmatic iceberg, glimpsed through a fog, is locked into a fjord, having calved from Kangerdlugssuaq glacier, one of the fastest moving outlet glaciers in Greenland. The glacier had an average speed of 15 metres a day between 2000 and 2010 Photograph: Dave Walsh/Millennium Images
An Arctic tern defending its nest in Ny-Ålesund, Svalbard, 746 miles from the north pole. Arctic terns fly to Antarctica and back to the Arctic every year, a round trip of more than 43,500 miles, or 1.5 million miles during their lives – the longest known migration of any animal or bird Photograph: Dave Walsh/Millennium Images
Formerly part of an Antarctica tabular ice shelf, an iceberg slumps into the Southern Ocean, near the mouth of the Ross Sea, Antarctica Photograph: Dave Walsh/Millennium Images
A blue river flows along a glacier, that is floating on the sea. One of Greenland’s most remote glaciers, Petermann has been in news in recent years for calving huge areas of ice from its floating tongue. In July 2012, a 50-mile slab broke free from its northern extent Photograph: Dave Walsh/Millennium Images
Shadows from the Tailenguak Cliffs fall across an iceberg floating in Kane Basin, calved from Greenland’s 68-mile wide Humboldt glacier – the widest tidewater glacier in the northern hemisphere Photograph: Dave Walsh/Millennium Images
Polar bear in the midnight sun, seen from the deck of the Greenpeace ship Arctic Sunrise in Kane Basin, northwest Greenland Photograph: Dave Walsh/Millennium Images
Tombstone-like ice formations on an iceberg in Kane Basin, northwest Greenland Photograph: Dave Walsh/Millennium Images
An iridescent blue iceberg in the Southern Ocean, near Antarctica. The blue is created from thousands of years of snow slowly compressed into a hard glacier. As air is squeezed out, ice crystals grow, absorbing light from the red end of the visible spectrum, leaving blue light to be refracted Photograph: Dave Walsh/Millennium Images
This massive Antarctic iceberg is reminiscent of the Böcklin painting 'The Isle of the Dead', depicting an oarsman rowing to a strange island, with a shrouded figure on board. Böcklin called it a 'a dream picture: it must produce such a stillness that one would be awed by a knock on the door' Photograph: Dave Walsh/Millennium Images
A repository for 4.5 million seeds from around the world, nestled into the rocky tundra of Svalbard’s Plataberget mountains, stored in case of disaster, disease, or war Photograph: Dave Walsh/Millennium Images
A vertical line of dense blue ice runs through an iceberg, at the mouth of Kangderluqussuaq Fjord, on Greenland’s east coast Photograph: Dave Walsh/Millennium Images
A pathway opens in landfast sea ice, in Dijmhna Sund, Nioghalvfjerdsfjorden, in Greenland’s remote and hard to reach northeast corner Photograph: Dave Walsh/Millennium Images
Walrus sleeping on a Sunday afternoon, at Poole-Pynten, Prins Karls Forland island, Svalbard, where centuries of hunting has pushed the animal to the edge of extinction, despite 50 years of protection Photograph: Dave Walsh/Millennium Images
Beluga whale skull on a piece of driftwood, near Mushamna trapping station, Woodfjorden, Svalbard Photograph: Dave Walsh/Millennium Images
A chunk of glacier ice floating in the natural channel of Torssaukatak, Kujalleq, southern Greenland, en route to Prins Christian Sund Photograph: Dave Walsh/Millennium Images
The fogbound, Arctic island of Parryøya, or Parry Island, in the Sjuøyane archipelago, northeastern Svalbard. Parryøya is 621 miles from the north pole, and 994 miles north of the Arctic Circle Photograph: Dave Walsh/Millennium Images
