Mites and springtails are the top predators of Antarctica's great range
The Transantarctic Mountains run about 3,500 km across the whole continent, dividing East from West Antarctica. On their rare ice-free ground, nematode worms graze on cyanobacteria and are hunted by mites and springtails, the apex predators of one of Earth's harshest ecosystems.
This mostly sedimentary range crosses Antarctica, with some gaps, from Cape Adare at the northern tip of Victoria Land all the way to Coats Land, between the Oates Coast and the Weddell Sea. At 100 to 300 km wide and roughly 3,500 km long, it is among the longest mountain chains on Earth and is made up of many separately named groups. Its highest summits exceed 4,500 m, and together with its dry valleys they are among the few places not buried by ice. The McMurdo Dry Valleys form the continent's largest snow-free area, kept bare by scant precipitation and ice loss.
Unlike the continent's mostly volcanic ranges, these mountains are old rock lifted up as the West Antarctic Rift System opened, starting about 65 million years ago, and glaciers moved in soon after. Beacon Supergroup sandstone, siltstone and coal, laid down from the Silurian into the Jurassic, rest on granite and gneiss and are cut by Jurassic Ferrar Dolerite; many of Antarctica's fossils come from these beds. Outlet glaciers carry East Antarctic ice through the range, usually at right angles to it, into the Ross Sea, the Ross Ice Shelf and the West Antarctic Ice Sheet.
The soils are salty, arid cryosols so dry that permafrost often freezes dry. Forests of Wollemi pines and southern beeches once grew in Antarctica but vanished as the climate cooled with Gondwana's break-up. Today penguins, seals and seabirds keep to the Victoria Land coast, while inland cyanobacteria are the main photosynthesisers, joined by algae in milder spots, lichens and patches of summer moss beside meltwater streams. Nematodes, tardigrades and rotifers graze on them, and mites and springtails prey on the grazers.
James Clark Ross's expedition first saw the range from the future Ross Ice Shelf on 10 January 1841. Robert Falcon Scott's party crossed into East Antarctica via the Ferrar Glacier in 1903, Shackleton went up the Beardmore Glacier in 1908, and in 1911 Scott returned to the Beardmore while Amundsen used the Axel Heiberg Glacier. Much of the range stayed unmapped until aerial surveys in the late 1940s and 1950s, and geologist Warren B. Hamilton first used the name Transantarctic Mountains in a 1960 paper.
Source: Transantarctic Mountains
