David Tipling / Chinstrap Penguins (Pygoscelis antarcticus) on blue iceberg, Antarctica

Juan Carlos Munoz / Detail in frozen waterfall. Selijalandfoss waterfall, Southern Iceland, Europe, March 2011.

Hiroya Minakuchi / Sea ice, Weddell Sea, Antarctic Peninsula, Antarctica

Solvin Zankl / Snowflake magnified under microscope, Lilehammer, Norway

Chadden Hunter / Brinicles (brine icicles or ice stalactites) forming under the ice, growing towards the sea floor, Ross Sea, McMurdo Sound, Antarctica. Taken on location for 'Winter' episode of the BBC Frozen Planet...

Erlend Haarberg / Glacier ice on sea shore, Jokulsarlon, Iceland, April 2010

Mark Hamblin / 2020VISION / Stac Pollaidh at dawn, with frozen Loch Lurgainn in foreground, Coigach, Wester Ross, Scotland, UK, December 2010

Mark Hamblin / 2020VISION / European river otter (Lutra lutra) footprints crossing frozen Loch Lurgainn at dawn, with Sgorr Tuath and Sgorr Deas (Beinn an Eoin) behind, Coigach, Wester Ross, Scotland, UK, December 2010

Mark Hamblin / 2020VISION / European river otter (Lutra lutra) footprints crossing frozen Loch Lurgainn at dawn, with Sgorr Tuath & Sgorr Deas (Beinn an Eoin) behind, Coigach, Wester Ross, Scotland, UK, December 2010

Peter Cairns / 2020VISION / Ice on mudflats, Morecambe Bay, Silverdale, Cumbria, England, UK, February

Roy Mangersnes / Mist above Monaco Glacier, North west of Spitsbergen, Svalbard, Norway, August

Brent Stephenson / Calm conditions with sea ice in the Lemaire Channel. Antarctic Peninsula, Antarctica, December.