Heard and McDonald Islands are an Australian Antarctic territory around 4,100 km south-west of Perth, WA. The islands were transferred from the UK in 1947, at which time a meteorological research station was established. The station was abandoned in 1955. Heard Island (73°30'E 53°05'S) and McDonald Island (73°36'E 53°02'S, 43 km west of Heard) are, with the French territory of the Kerguelen Islands (or Kerguelen Archipelago, 440 km north-west) the only exposed portions of the submarine Kerguelen Plateau. Because there is very little land in this part of the Southern Ocean, the landscapes and wildlife of Heard and McDonald Islands are unique. The islands are also home to Australia's only active volcanoes.
The dominating feature of Heard Island is Big Ben, a mountain covering 380 km2 (almost the entire island). The pinnacle of Big Ben is Mawson's Peak (2,745 m). At the centre of the peak is a crater 70 m deep, containing molten lava. There have been a number of recorded eruptions of Big Ben, the last major incident being an eruption in February 2001, following several months of heightened volcanic activity from late 2000.
McDonald Island (230 m above sea level) is a much smaller island made of two parts connected by a narrow central isthmus. The island began to erupt in 1992 after lying dormant for 75,000 years, and has erupted several times since. Satellite pictures revealed in 2001 that the island had doubled in size. The island is home to a variety of subantarctic fauna and flora, and scientists believe that the volcanic activity will not, at this stage, have any long-term serious effects on the wildlife. McDonald Island, like Heard, is very difficult to access because of its cliff-lined coasts and rocky shoals. There have only ever been two successful landings on the island.