The teenager and his guide, Carl Alvey, travelled across the Antarctic on skis, unsupported except for a few food drops and braving temperatures as low as minus 50C, according to Clarke's website.

"I'm really happy but mostly relieved that for the first time in 48 days I don't have to get up tomorrow and drag my sled for nine hours in the snow and icy wind," Clarke said in a statement carried by the British media.