Document ID: chunk:federal_register_of_legislation:F2013L01343:front:0:p16
Version: federal_register_of_legislation:F2013L01343
Segment Type: other
Provision Reference: 
Character Range: 40890–43567

snow and glacial moraine. The largest, most westerly valley contains the four AAE huts. At the seaward end of this valley is Boat Harbour, a 400 m long indent in the coast.

The landscape is strewn with glacial deposits. Large boulder fields are coloured with lichen, the only known flora on Cape Denison. There are six melt water lakes associated with glacial action. The site is however renowned for its wind.

    Wind is the dominant feature that has shaped occupation of this place, and continues to define the landscape. The wind makes it different from most other Antarctic landscapes, and sets it apart from the sites of other Heroic Era huts. Sun, cloud and seasonal changes in daylight and darkness are largely irrelevant compared to the cycle of katabatic winds that creates an annual average daily maximum wind speed of 71 km per hour. Frequent blizzards and gusts exceed 100 km per hour: in 1913 the wind was recorded at 143 km per hour for twelve continuous hours (Godden Mackay Logan 2001).

Humans perceive this wind as a constant force (rather than the perception of eddies and gusts usually associated with winds). This force, always from the south, carries huge amounts of drift snow and ice before it, often creating blizzards, and whips the sea into a chop topped with fierce spume only metres from the shore. Surface temperatures, not including the wind chill factor, generally range from -21° and lower in winter, to -3° in summer, with occasional days approaching zero or above

The area contains many geological features that are important for the understanding of the Gondwana break-up 55 million years ago, as it was roughly opposite what is now the Gawler Craton in South Australia. The area can be divided into a 'lower zone of relatively polished rock and a higher zone of relatively unpolished rock'. Glacial plucking is common and generates a roches moutonnee effect with gentler, smoother surfaces towards the ice source and a rougher, more plucked downslope area. There are abundant glacial erratics and striated surfaces.

The 'upper' moraine, close to the ice edge and containing a great diversity of rocks, many unknown in outcrop in the area, is a genuine moraine. Boulders are more angular and sorting less obvious than in the 'lower' moraine. The rocks, including little studied red sandstone and crystalline limestone, from which no fossils have been recovered, may provide an insight into the rocks that underlie the ice of this part of Antarctica.

The 'lower' moraine can extend up to 36 m above sea level and is dominated by local rocks. This feature may be a result of 'ice push' from the sea rather than a genuine glacial moraine.