The following answer has been selected and edited by New Scientist staffThe furthest point from the sea or, to give its technical name, the
continental pole of inaccessibility (CPI), does lie in Asia. It is located at 46° 17' N, 86° 40' E, in the Dzoosotoyn Elisen in Xinjiang, China, and is 2648 kilometres from the nearest coastline, at Tianjin on the Yellow Sea. Although its location was calculated long ago, it wasn't visited by surveyor-explorers until 27 June 1986, when it was reached by British cousins Nicholas Crane and Richard Crane.The Cranes travelled there by bicycle, crossing the Hindu Kush and Gobi deserts, to raise funds for the Intermediate Technology Development Group (which has since been renamed
Practical Action) - a charity that supports technological advances in developing countries.Twenty years before that, however, the CPI attracted the attention of another group with very different interests. Its unique geographical status gave it considerable significance among western nuclear strategists debating the relative merits of weapons systems. For proponents of the submarine-launched Polaris missile, the ability to hit any point on the Earth - even if there is nothing there worth hitting - became a key point in the public relations battle with the sponsors of land-based and air-launched weapons.When the A3 version of Polaris brought the CPI within range in the late 1960s, it was hailed as a technological triumph - particularly by the UK's Ministry of Defence. They did not, however, trumpet the fact that to strike the pole a large nuclear-powered submarine would practically have to visit Tianjin docks.Ironically, by the time the western navies acquired the capacity to bombard all of China with submarine-launched missiles, the region around the CPI was probably featuring more prominently on the targeting lists of generals in Moscow, rather than London or Washington DC, as Xinjiang acquired vital strategic significance in the Sino-Russian confrontation of the last quarter of the 20th century.Finally, while appreciating the irony in your correspondent's choice of attire, he should reflect that the CPI is subject to extreme climatic continentality: summers are hotter and winters are colder than many places of similar latitude because it is so far from the moderating influence of the ocean. "Elisen" means "desert" in the local Chinese Uighur dialect, and although the location is certainly sandy, it is no beach.Indeed, this part of Xinjiang might be considered an extension of the Gobi, which is a decidedly cold desert where temperatures drop to -40 °C in winter. At the other extreme, during daytime in summer it can reach a blistering 50 °C, though temperatures can vary by as much as 32 °C within a 24-hour period. If he insists on wearing his trunks, I suggest that he keeps a warm pullover handy, just in case.Hadrian Jeffs, Norwich, UK
