Matthias Breiter / Meltwater lakes on Hubbard Glacier, Wrangell-St. Elias National Park, Alaska

Jeff Wilson / Camera crew searching for crevasse to film in, Gorner glacier, near Zermatt in the Swiss Alps, Switzerland. For BBC Planet Earth series, Mountains episode, 2006

Jeff Wilson / Film crew lowering camera into crevasse in Gorner glacier, near Zermatt in the Swiss Alps, Switzerland, for BBC Planet Earth series, Mountains episode, 2006

Angelo Gandolfi / Chamois (Rupicapra rupicapra) jumping over crevasse in the snow, Abruzzo National Park, Italy.

Angelo Gandolfi / Chamois (Rupicapra rupicapra) jumping over crevasse in the snow, Parco Nazionale delle Alpi Marittime, Alps, Italy.

Angelo Gandolfi / Chamois (Rupicapra rupicapra) jumping over crevasse in the snow, Parco Nazionale delle Alpi Marittime, Alps, Italy

Doug Allan / Crossing a crevasse ladder in the Khumbu Icefall on Mount Everest Nepal. Model released. Freeze Frame book plate page 143.

Shane Gross / Hawksbill turtle (Eretmochelys imbricata) swimming over coral reef crevasse, view from below. Caribbean Sea off Gardens of the Queen National Park, Cuba.

Ingo Arndt / Ice ridges, Grey Glacier, Torres del Paine National Park, Patagonia, Chile

Heike Odermatt / Glacial crevasse of coastal glacier, Kross Fjord, Spitsbergen, Svalbard, Norway

Ashley Cooper / Climbers on the arete leading up from the Vallee Blanche to the Aiguille Du Midi above Chamonix, France. September 2014

Ashley Cooper / Mont Blanc Du Tacul with mountaineers climbing the peak. From the Aiguille Du midi, above Chamonix, France, September 2014