On 28 February 1912, less than six weeks after Aurora’s departure, Mawson, Bage and Madigan took the first sledge journey south out of Cape Denison — ‘a short reconnaissance’. Short indeed: after 1.5 kilometres, ‘in the face of a disagreeable head wind and drifting snow’, the trio was forced to turn back.

Picking up their sledge the next day, they struggled a further seven kilometres up the slope to an altitude of 450 metres, where they erected a flagpole and left, anchored into the ice, a loaded sledge and a box containing a thermograph, to record temperature. As Mawson later wrote:

… we had demonstrated by this short excursion that a good sledging track to the interior lay to the south of Cape Denison, and we needed only an improvement in the weather to extend rapidly our knowledge of the surrounding area.

Winter was no time for sledging, but that did not deter Ninnis and Mertz. Eager to test out their charges, on the last day of July they took dog teams to the ‘Magnetic Cave’, an ice dugout used for magnetic observations about a kilometre inland from the Cape. Then on 9 August Mawson, Ninnis and Madigan took an eight-dog team up the ice to the spot where the previous autumn they had abandoned their sledge and a thermograph (which had recorded a minimum temperature of minus 36.7 degrees C).

At this otherwise unremarkable place on the windswept ice sheet, the three men dug deep into the ice, making a cavern to serve as a depot and refuge for sledge parties. It was an inspired decision. On bleak, windy days, ‘Aladdin’s Cave’, as it became known, would prove a haven of peace and sustenance when the katabatic was at its fiercest and bodies near their limit.

Mawson’s party ventured another six kilometres to the south. For their return journey they had a fierce tailwind that caused havoc with the dog teams, which were released to find their own way home. When the dogs failed to return, Bage, Mertz and Hurley headed off to rescue them. Continuing winds held them up for five days, but they finally found the hardy animals outside Aladdin’s Cave — all still alive despite having not eaten for a week. All but one survived the ordeal.