Circumnavigation


Circumnavigation

Circumnavigation – literally, "navigation of a circumference" – refers to travelling all the way around an island, a continent, or the entire planet Earth.

Contents

Global circumnavigation

The route of a typical modern sailing circumnavigation, via the Suez Canal and the Panama Canal is shown in red; its antipodes are shown in yellow.

In principle, if a person walks completely around either Pole, they will have crossed all meridians, but this is not generally considered a "circumnavigation." A basic definition of a global circumnavigation would be a route which covers at least a great circle, and in particular one which passes through at least one pair of points antipodal to each other.[1] In practice, different definitions of world circumnavigation are used, in order to accommodate practical constraints depending on the method of travel. Since the planet is a sphere, a trip from one Pole to the other, and back again, would technically be a circumnavigation, but practical difficulties generally preclude such a voyage.

For the wealthy, long voyages around the world, such as was done by Ulysses S. Grant, became possible in the 19th century, and the World Wars moved vast numbers of troops around the planet. However, it was later improvements in technology and rising incomes that made such trips relatively common.

Nautical

The map on the right shows, in red, a typical sailing circumnavigation of the world by the trade winds and the Suez and Panama canals; overlaid in yellow are the points antipodal to all points on the route. It can be seen that the route roughly approximates a great circle, and passes through two pairs of antipodal points. This is a route followed by many cruising sailors, going in the western direction; the use of the trade winds makes it a relatively easy sail, although it passes through a number of zones of calms or light winds.

The route of a typical yacht racing circumnavigation is shown in red; its antipodes are shown in yellow.

In yacht racing, a round-the-world route approximating a great circle would be quite impractical, particularly in a non-stop race where use of the Panama and Suez Canals would be impossible. Yacht racing therefore defines a world circumnavigation to be a passage of at least 21,600 nautical miles (40,000 km) in length which crosses the equator, crosses every meridian and finishes in the same port as it starts.[2] The map on the left shows the route of the Vendée Globe round-the-world race in red; overlaid in yellow are the points antipodal to all points on the route. It can be seen that the route does not pass through any pairs of antipodal points. Since the winds in the higher latitudes predominantly blow west-to-east it can be seen that there is an easier route (west-to-east) and a harder route (east-to-west) when circumnavigating by sail; this difficulty is magnified for square-rig vessels.

For current sailing records, see article : Around the world sailing record. For around the world sailing records, there is a rule saying that the length must be at least 21,600 nm calculated along the shortest possible track from the starting port and back that does not cross land and does not go below 63°S. It is allowed to have one single waypoint to lengthen the calculated track. The equator must be crossed.[3]

Since the advent of world cruises in 1922, by Cunard's Lanconia, thousands of people have completed circumnavigations of the globe at a more leisurely pace. Typically, these voyages begin in New York City or Southampton, and proceed westward. Routes vary, either travelling through the Caribbean and then into the Pacific Ocean via the Panama Canal, or around Cape Horn. From there ships usually make their way to Hawaii, the islands of the South Pacific, Australia, New Zealand, then northward to Hong Kong, South East Asia, and India. At that point, again, routes may vary: one way is through the Suez Canal and into the Mediterranean; the other is around Cape of Good Hope and then up the west coast of Africa. These cruises end in the port where they began.

Aviation

Since the development of commercial aviation many thousands of people have flown around the world. Some regular routes, such as the old Pan American Flight One (and later, although briefly, United Airlines Flight One), circled the globe, and today planning such a trip through various connections is quite simple.

The first flying man-made airship to circumnavigate the world was the LZ 127 Graf Zeppelin, which did so in 1929.

Aviation records take account of the wind circulation patterns of the world; in particular the jet streams, which circulate in the northern and southern hemispheres without crossing the equator. There is therefore no requirement to cross the equator, or to pass through two antipodal points, in the course of setting a round-the-world aviation record. Thus, for example, Steve Fossett's global circumnavigation by balloon was entirely contained within the southern hemisphere.

For powered aviation, the course of a round-the-world record must start and finish at the same point and cross all meridians; the course must be at least 36,787.559 kilometres (22,858.729 mi) long (which is the length of the Tropic of Cancer). The course must include set control points at latitudes outside the Arctic and Antarctic circles.[4]

In ballooning, which is totally at the mercy of the winds, the requirements are even more relaxed. The course must cross all meridians, and must include a set of checkpoints which are all outside of two circles, chosen by the pilot, having radii of 3,335.85 kilometres (2,072.80 mi) and enclosing the poles (though not necessarily centred on them).[5]

Astronautics

The first person to fly in space, Yuri Gagarin, became also the first to complete an orbital spaceflight on spaceship Vostok 1, in 1961. Early NASA space missions included only sub-orbital spaceflights. The first American, and third human, to orbit Earth was John Glenn in 1962.

Human-powered

According to AdventureStats by Explorersweb, Jason Lewis completed the first true human-powered circumnavigation of the globe while National Geographic (http://www.nationalgeographic.com/adventure/best-of-adventure-2007/achievements/colin-angus-julie-wafaei.html) lists Colin Angus as being the first to complete a global circumnavigation. While neither Lewis or Angus met the criteria of Guinness World records, each completed continuous human powered journeys around the planet. [6] David Kunst was the first verified person to walk around the world between 20 June 1970 and 10 October 1974. Guidelines issued by Guinness World Records in March 2007 state that a human powered circumnavigation must travel a minimum of 36,787.559 km (the distance of the Tropic of Cancer), cross the Equator, and each leg must commence at the exact point where the last finished off. To date no one has completed a human-powered circumnavigation according to the guidelines set by Guinness.[7][8][9]

People have both bicycled and run around the world,[10] but the oceans have had to be covered by air travel, making the distance shorter than the Guinness guidelines. To go from North America to Asia on foot is theoretically possible but very difficult. It involves crossing the Bering Strait on the ice and around 3000 km roadless swamped or freezing cold area in Alaska and eastern Russia. No one has so far travelled all of this route by foot.

Notable circumnavigations

Maritime

  • Fernão de Magalhães (Ferdinand Magellan) and Juan Sebastián Elcano's 1519-1522 expedition was the first documented world circumnavigation. At the behest of the Spanish Crown Magellan, a portuguese sailor, led the first expedition to circumnavigate the world, sailing between August 1519 and April 1521. However, he was killed in a battle in the Philippine island of Cebu on April 27, 1521. His second in command, the Spaniard Juan Sebastián Elcano, from Getaria, completed the journey back through the Indian Ocean and round the Cape of Good Hope to Spain in 1522. The 18 survivors of this expedition including Elcano, on the Victoria completed the circumnavigation returning to Sanlucar de Barrameda on 8 September 1522 after a journey of 3 years and 1 month. (Seventeen more survivors later returned.) These were the first known navigators to circumnavigate the world.[11] Sanlucar de Barrameda 2019-2022 is an initiative that is being planned to celebrate the fifth centenary of the first circumnavigation of the Earth, which departure point and return were in the city of Sanlúcar de Barrameda, Cádiz, Spain.
  • Joshua Slocum, 1895–1898, first single-handed circumnavigation.

Aviation

  • United States Army Air Service, 1924, first aerial circumnavigation, 175 days, covering 44,360 kilometres (27,560 mi).
  • In 1949, the Lucky Lady II, a Boeing B-50 Superfortress of the U. S. Air Force, commanded by Captain James Gallagher, became the first airplane to circle the world nonstop. This was achieved by refueling the plane in flight.

References


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Look at other dictionaries:

  • circumnavigation — [ sirkɔmnavigasjɔ̃ ] n. f. • circonnavigation 1788; de circum et navigation ♦ Didact. Voyage maritime autour d un continent. ⇒ périple. ● circumnavigation nom féminin Voyage maritime autour d un continent ou de la Terre. ● circumnavigation… …   Encyclopédie Universelle

  • circumnavigation — ou circonnavigation (sir kon na vi ga sion) s. f. Navigation autour. •   Si dix huit ou vingt siècles et la circumnavigation de l Afrique et des Indes ont si peu ajouté, en ce genre, à ce que les anciens nous ont appris, il n y a pas d apparence… …   Dictionnaire de la Langue Française d'Émile Littré

  • Circumnavigation — Cir cum*nav i*ga tion, n. The act of circumnavigating, or sailing round. Arbuthnot. [1913 Webster] …   The Collaborative International Dictionary of English

  • Circumnavigation — (v. lat.), Umschiffung …   Pierer's Universal-Lexikon

  • Circumnavigation — Circumnavigation, Umschiffung …   Herders Conversations-Lexikon

  • circumnavigation — (n.) 1705, from CIRCUMNAVIGATE (Cf. circumnavigate) + ION (Cf. ion) …   Etymology dictionary

  • Circumnavigation — Sur les autres projets Wikimedia : « circumnavigation », sur le Wiktionnaire (dictionnaire universel) En rouge, la route d une course à la voile classique autour de la terre. La circumnavigatio …   Wikipédia en Français

  • CIRCUMNAVIGATION — n. f. Navigation autour du globe terrestre. Le premier voyage de circumnavigation fut exécuté par Magellan. Il se dit aussi d’une Navigation faite autour d’un continent. La circumnavigation de l’Afrique …   Dictionnaire de l'Academie Francaise, 8eme edition (1935)

  • circumnavigation — circumnavigate ► VERB ▪ sail all the way around. DERIVATIVES circumnavigation noun …   English terms dictionary

  • circumnavigation — noun traveling around something (by ship or plane) Magellan s circumnavigation of the earth proved that it is a globe • Derivationally related forms: ↑circumnavigate • Topics: ↑airplane, ↑aeroplane, ↑plane • Hypernyms …   Useful english dictionary


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