Chadden Hunter / Delicate ice crystal formations inside volcanic ice cave, Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Chadden Hunter / Entering the ice caves of Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Chadden Hunter / Cameraman Gavin Thurston filming ice crystals under volcanic ice cave, Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Chadden Hunter / Filming around the extremely delicate ice formations in volcanic ice cave, Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Chadden Hunter / BBC producer Chadden Hunter looking at the incredible ice crystal formations inside volcanic ice caves below Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Chadden Hunter / Delicate ice crystal formations inside volcanic ice cave, Mount Erebus, Antarctica. Taken on location for BBC Frozen Planet series, 2009

Chadden Hunter / Cameraman Gavin Thurston filming ice crystals under volcanic ice cave, Mount Erebus, Antarctica. Due to delicate nature of the crystals Gavin used video function on SLR camera. Taken on location for B...

Bryan and Cherry Alexander / Male Killer whale (Orcinus orca) hunting along the floe edge by Mount Erebus. Ross Sea, Antarctica.

Colin Monteath / Mount Erebus at midnight with ice floes in McMurdo Sound, Ross Island, Antarctica

Colin Monteath / Science research base on Ross Island with Mount Erebus behind, Antarctica

Colin Monteath / Marina Svetaeva, an ice-strengthened Russian cruise ship in McMurdo Sound sea ice, Ross Sea, Antarctica

Colin Monteath / Scientists and field assistants view Mt Discovery from the summit of Mt Erebus, Ross Island, Antarctica