Prince Edward Islands
The Prince Edward Islands (332 km²) comprise
a group of two small islands — Marion Island and Prince Edward Island — located in the far
southern waters of the Indian Ocean at a latitude of 46° South. The islands are situated 1,760 km
southeast from the South African coast at Port Elizabeth and 1,060 km west from the
Crozet Islands; the Antarctic coast lies 2,360 km to the south. With the exception
of a permanently inhabited scientific research station the islands have no civilian population.
At 290 km² in area, Marion Island is the largest of the islands, measuring 24 km in length (east to west) and 15 km in width (north to south). The island is the emergent summit of a mildly active shield volcano that rises from the sea floor — around 5,000 m below — from a point south of the Southwest Indian Ocean Ridge. Prince Edward Island, 20 km to the northeast, is a smaller, secondary summit of this twin-peaked volcano. The island was thought to be volcanically extinct until the 1980 eruption of Kaalkoppie produced a lava flow on the west coast of the island. Since then, small scale signs of continuing activity have been observed in 2004 and 2005. Many of the numerous scoria cones that pepper the landscape (red-coloured conical peaks in the large size image) are only a few hundred years old — testament to the fact that, at less than 500,000 years in age, Marion is a geologically very young island.
Marion Island, rising to a height of 1,230 m above sea level at the cratered State President Swart Peak, has a generally hilly interior of low rounded hills — the results of extensive glaciation in the recent past. The landscape is volcanic in appearance, being dominated by recent (< 15,000 years) flows of aa and pahoehoe lavas. Signs of volcanic activity are everywhere evident: there are around 150 tuff, scoria and cinder cones scattered along the coast and throughout the interior. Much of the landscape is barren, consisting of pebble and boulder fields, bare slopes, and lava flows and is generally devoid of vegetation cover. The highest reaches of the interior are covered by a few remnant patches of the receding Ice Plateau Glacier — snow cover in this region is usually perennial. At lower, flatter elevations, vegetation cover consists of mosses, ferns and grasses — high rainfall creates marsh, peat and bog communities. From the interior, the terrain of Marion Island generally drops to the sea in steep cliffs and rugged slopes. Its coastline of 72 km in length, where level, consists mainly of small stony to rocky beaches, with a few sandy coves being the exception.
Located 20 km northeast from Marion Island, lies the smaller Prince Edward Island. The island measures 10 km in length with a maximum width of 6 km, covering an area of 42 km².
The Prince Edward Islands, being located in the land-poor sub-Antarctic, form important breeding grounds for many species of mammal and bird — some of which are internationally and regionally significant. The King Penguin (Aptenodytes patagonicus) colony on Marion is the second largest in the world. Other penguin species found in large numbers include Rockhopper (Eudyptes chrysocome), Gentoo (Pygoscelis papua) and Macaroni (Eudyptes chrysolophus). The beaches of the islands are also used as breeding grounds for large mammals such as the Southern Elephant Seal (Mirounga leonina), Sub-Antarctic Fur Seal (Arctocephalus tropicalis) and Antarctic Fur Seal (Arctocephalus gazella).
