As a British team of explorers set off for the frozen continent of Antarctica on a challenging expedition to the south pole and back, we asked polar photographer Martin Hartley to open his archive.
With temperatures down to -40 Celcius, the polar regions are an unforgiving and brutal place. But for the few adventurers who manage to journey to these remote outposts of our planet, the reward is a place of unimaginable beauty.
Once voted a 'hero of the environment' for taking part in a scientific mission to the North Pole, Hartley has been documenting Arctic, Antarctic and mountaineering expeditions for over 10 years. Check out more of his work at www.martinhartley.com.