Quadripoint

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Plaque that marks the only state quadripoint in the United States; where Arizona, Utah, Colorado and New Mexico meet.

In geography, a quadripoint is a point on the Earth that touches four distinct regions. Such points are often called four corners, from the corners of the four regions meeting there.[1]

Contents

[edit] International quadripoints

At present there are no generally recognized quadripoints involving four different countries, although a claim is often made that one exists at 17°47′32″S 25°15′52″E / 17.79222°S 25.26444°E / -17.79222; 25.26444 (Zambezi-Chobe confluence) between Namibia, Zambia, Zimbabwe and Botswana at the thalweg confluence of the Zambezi River with the Chobe River near Kazungula. The various boundary definitions involved are subject to differing and disputed interpretations; only one combination of interpretations and river conditions might have produced a quadripoint, but that combination never obtains in reality.[2][3]

[edit] Close calls

If the Kazungula case above is not accepted as a quadripoint, it is the place where tricountry points are closest together, as the distance between the tripoints is believed by the most exacting research to be less than 300 meters and indeed very much as it is shown on this best available map. [[1]]

Where two tripoints occur very close to each other, they can look like a quadripoint on a map of insufficient resolution. For example, the Kazakhstan/Russia/People's Republic of China tripoint at 49°5′59″N 87°18′45″E / 49.09972°N 87.3125°E / 49.09972; 87.3125 (China/Mongolia/Russia tripoint) is only 39 km from Tavan Bogd Uul, a Russia/Mongolia/People's Republic of China tripoint. It may look like a quadripoint on some maps, but at more detailed resolution, it is clear that Kazakhstan and Mongolia never touch.[4]

The two tripoints of Morocco/Algeria/Western Sahara and Algeria/Western Sahara/Mauritania located South-West of the Algerian city of Tindouf are about 40 km apart.

An even closer example of this is between the tripoints of Armenia/Turkey/Nakhichevan, Azerbaijan and Iran/Turkey/Nakhichevan, Azerbaijan, which are about 9 km from each other at 39°41′0″N 44°48′30″E / 39.683333°N 44.80833°E / 39.683333; 44.80833 (Border tripoints).

Lake Chad, showing international borders

Although four countries border Lake Chad, there is no quadripoint of Chad, Niger, Nigeria, and Cameroon within the lake. The two tripoints are about 86 km apart.

Similarly, the Gulf of Aqaba in the Red Sea borders four countries, but does not contain a quadripoint of Jordan, Saudi Arabia, Egypt, and Israel.

Some political maps of the South Pacific enclose many island nations within straight lines drawn along parallels of latitude or meridians of longitude, often with a maritime quadripoint indicated for Solomon Islands, Tuvalu, Kiribati, and Nauru.[5] This is not a meaningful quadripoint, as the lines are simply cartographic conveniences to indicate which country the islands within it belong to, and are thus merely allocational lines rather than actual international boundaries of territorial waters or Exclusive Economic Zones.[6]

[edit] Previously existing would-be four-country points

Between 1830 and 1920 there was a quadripoint at the convergence of Belgium, Prussia/Germany, the Netherlands, and Moresnet. 50°45′N 6°01′E / 50.75°N 6.02°E / 50.75; 6.02 (former quadripoint) [2] [3] This point has often been called a quadricountry point, though Moresnet was never truly a country but rather only a neutral territory or condominium of the Netherlands and Prussia (originally), and of Belgium and Germany (ultimately).

From 1922 to 1991 there was a de facto quadripoint 29°06′N 46°33′E / 29.1°N 46.55°E / 29.1; 46.55 (former quadripoint) between Iraq, Kuwait, Kingdom of Nejd/Saudi Arabia and the Saudi-Iraqi neutral zone, although precise boundaries were never specified by the three sovereign states.

[edit] Fewer than four countries

There are quadripoints where four border lines touch each other at one point, but involving fewer than four countries. This occurs with a practical exclave which touches the main territory (or another exclave) at a single point. The Belgian enclaves H1 and H2 in Baarle-Hertog touch each other at one such point, while the Netherlands also crosses it.[7]

Similarly, the Austrian town of Jungholz lies totally within Germany except that it borders Austria at one single point.

Cooch Behar in India is linked with Bangladesh by at least one such point (and very possibly a second).

[edit] Secondary quadripoints

A secondary quadripoint (or "quadrisecondary point") is the meeting of four political subdivisions (for example, provinces, states, or cantons). The four subdivisions may all belong to one country, or they may involve two or three different countries.

By analogy, one could speak of tertiary quadripoints ("quadritertiary points") where, for example, four different counties meet at one point, and quaternary quadripoints ("quadriquaternary points") where four municipalities meet, etc. However, these lesser categories would not have been considered as interesting as primary or "world class" quadripoints, if indeed any such quadricountry points had ever actually existed. For example, many counties in the Midwest or towns in Maine are demarcated as squares on a grid.

[edit] Trinational

At 54°21′52″N 22°47′32″E / 54.36435°N 22.79228°E / 54.36435; 22.79228, there is a trinational secondary quadripoint: to the northwest is Russia (specifically the Russian exclave Kaliningrad Oblast); to the northeast Lithuania; and to the southwest and southeast two Voivodships (provinces) of Poland: Warmian-Masurian Voivodship and Podlaskie Voivodeship. [4] The quadripoint exists thanks to the way the border between Poland and Russian SFSR was defined in 1945 by the Potsdam Agreement. The new border between Poland and the USSR bisected Germany's former province of East Prussia; the northern part became Kaliningrad Oblast, and most of the southern part is now Warmia-Masuria.

At or around 19°N 52°E / 19°N 52°E / 19; 52, there appears to be another trinational secondary quadripoint: to the north is Saudi Arabia, to the southeast is Oman, and to the southwest two Governorates of Yemen: Hadhramaut Governorate to the westsouthwest and Al Mahrah Governorate to the southsouthwest.[8]

[edit] Binational

The three German states Bavaria, Saxony and Thuringia do not form a quadripoint with the Czech Republic (the two tripoints are about 20 km apart); nevertheless it is commented on.

A similar seeming quadripoint exists near Biaufond at 47°09′56″N 6°51′36″E / 47.1655°N 6.86°E / 47.1655; 6.86 between the Swiss cantons of Jura, Neuchâtel, and Berne on the one hand, and the French département Doubs on the other hand. In this case, the two tripoints are separated by only about 250 m/830 ft.

On the border of Sweden and Norway, at 65°07′08″N 14°19′33″E / 65.11888°N 14.32592°E / 65.11888; 14.32592, there appears to be a binational secondary quadripoint where two Counties of Norway, Nord-Trøndelag and Nordland, meet two Counties of Sweden, Västerbotten County and Jämtland County.[8] [5]

Another binational secondary quadripoint appears to exist on the border of Argentina and Uruguay where the Argentinian provinces of Corrientes and Entre Rios also very possibly meet the Uruguayan departments of Artigas and Salto.

And a third may occur on the border of Malawi and Mozambique where the Phalombe and Zomba districts of the former meet the Niassa and Zambezia provinces of the latter at a marked turnpoint on the southeast shore of Lake Chilwa.

[edit] National

The Argentine provinces of La Pampa, Río Negro, Mendoza and Neuquén form a quadripoint at 37°34′00″S 68°14′00″W / 37.5666667°S 68.2333333°W / -37.5666667; -68.2333333, though Rio Negro has disputed this since a 1966 resurvey cast the exact boundary convergence into some doubt.

The Four Corners is the only point in the United States of America where four states meet: Colorado, Utah, New Mexico, and Arizona meet at right angles.

A map highlighting the Four Corners of Canada, where the borders of four Canadian provinces and territories intersect.

There has been an analogous Four Corners in Canada at 60°N 102°W / 60°N 102°W / 60; -102 since the creation of Nunavut in April 1999; it meets Saskatchewan at a point, with Manitoba and the Northwest Territories at the other corners. The point is located near the southern shore of Kasba Lake in a remote northern wilderness. The point is marked by a metre-high aluminium obelisk which was erected in 1962 (before the creation of Nunavut). Before 1999 this was a tertiary quadripoint, with Manitoba, Saskatchewan, and the then existing Northwest Territories districts of Mackenzie and Keewatin.

In Mexico there is only one precise quadripoint at 24°33′00″N 100°48′00″W / 24.55°N 100.8°W / 24.55; -100.8. The "Mojonera de los cuatro estados" ("Four State Boundary Stone") was built to mark the point where Coahuila, Nuevo Leon, San Luis Potosi and Zacatecas states effectively meet.

The Mexican territory also has two apparent quadripoints, that can easily be misinterpreted as such in a low resolution map. One of them is located at 22°23′07″N 104°21′33″W / 22.38528°N 104.35917°W / 22.38528; -104.35917, where the states of Durango, Jalisco, Nayarit and Zacatecas apparently meet. Actually, there are two tripoints separated by more than 13 kilometers (8 miles), because Durango and Jalisco never really touch each other. The other is located at 21°50′01″N 101°32′17″W / 21.83361°N 101.53806°W / 21.83361; -101.53806, where the states of Guanajuato, Jalisco, San Luis Potosi and Zacatecas seem to meet; actually Jalisco and San Luis Potosi are separated by more than 11 kilometers (7 miles).

Four provinces of the Philippines meet at a point on Mindanao island, probably at one of the three peaks of Mount Apo: Bukidnon, Davao del Norte, Davao del Sur, and Cotabato.

There are two quadripoints in Switzerland where three cantons meet. At each, a practical exclave of one canton touches its parent, while two other cantons touch each other. One is near 47°24′51″N 7°22′33″E / 47.41417°N 7.37583°E / 47.41417; 7.37583, where the municipality of Roggenburg is cut off from its parent Basel-Country by Jura to the south and an exclave of Solothurn to the north. The other is near 47°19′20.5″N 7°33′30″E / 47.322361°N 7.55833°E / 47.322361; 7.55833 where Jura again touches Solothurn, cutting off the municipality of Schelten from its parent canton of Bern.[9]

Other countries that enjoy positively confirmed or at least very probable secondary quadripoints are Andorra, Bulgaria, Colombia, the Dominican Republic, Gabon, India, Jamaica, Liechtenstein, Libya, Mauritania, Oman, Sudan, Uganda, and Vietnam.

[edit] United Kingdom

An analysis of county quadripoints in the United Kingdom is complicated by multiple changes to the borders and numbers of administrative counties in the last century (see Administrative counties of England). No true quadripoints remain in the United Kingdom.

Until the late nineteenth century, one quadripoint did exist; near Evenlode in Gloucestershire, is "Four Shire Stone",[10] formerly at an intersection of Gloucestershire, Oxfordshire, Warwickshire, and a detached fragment of Worcestershire. However, the fragment has been reassigned, leaving only a tripoint around ten miles (16 km) from modern Worcestershire.[11]

In addition there are a few near misses. The most famous lies south west of Stamford – where Rutland, Lincolnshire, Cambridgeshire and Northamptonshire seem to meet at a point. (52°38′25″N 0°29′40″W / 52.64028°N 0.49444°W / 52.64028; -0.49444) However, the location actually consists of two tripoints around 20 metres apart.[12]

In addition near East Grinstead, the East Sussex-West Sussex-Surrey and East Sussex-Surrey-Kent tripoints are only a mile apart. Similarly the Staffordshire-Warwickshire-Leicestershire (SK278100) and Warwickshire-Leicestershire-Derbyshire (SK273114) tripoints are again around a mile apart - the place name of No Man's Heath nearby is suggestive. And until 1965, the two tripoints formed by Gloucestershire, Oxfordshire, Wiltshire and Berkshire near Lechlade came very close to one another. (51°41′20″N 1°40′37″W / 51.68889°N 1.67694°W / 51.68889; -1.67694).

[edit] Five or more regions

At subnational level, one can find even more than four divisions converging at a point.

Tertiary quintipoint:

  • In the Philippines:
    • Municipalities of Tagkawayan, Quezon Province; Labo, San Vicente and San Lorezo Ruiz, Camarines Norte; and Del Gallego, Camarines Sur
    • Cities of Cadiz, Sagay, Silay and Talisay, and municipality of Calatrava, Negros Occidental[citation needed]
    • Municipalities of Carmen, Batuan, Bilar, Dimiao, and Valencia, Bohol
    • Municipalities of San Miguel, Ubay, Alicia, Dagohoy and Pilar, Bohol
    • Malaybalay City, Sumilao, Baungon, Talakag and Lantapan, Bukidnon
    • Municipalities of Carmen, Aleosan, Pikit and Kabacan, Cotabato; and Pagagawan, Maguindanao
    • Municipalities of Tibiao and Barbaza, Antique; Madalag and Libacao (a close call?), Aklan; and Jamindan, Capiz
Mayon volcano, with converging administrative boundaries marked in grey.

Tertiary sexipoint:

  • Municipalities of Basey and Marabut, Samar; and Balangkayan, Llorente, Balangiga and Lawaan, Eastern Samar, Philippines

Tertiary septipoint:

Tertiary octopoint:

[edit] References

This article was originally translated from the Dutch-language wiki article nl:Vierlandenpunt, as of 2006-06-20 [6], with the assistance of SystranBox online machine translation.

  1. ^ One could argue that, if one region lies on one side of a straight line border, and the other three are on the opposite side of this line, there are only three corners plus a straight line. However in geometry the straight line in this context would be considered to form a straight angle measuring 180°.
  2. ^ Brownlie, Ian; Ian R. Burns (1979). "Botswana-Zambia (Quadripoint issue)". African Boundaries: A Legal and Diplomatic Encyclopaedia. London: C. Hurst & Co.. pp. 1098–1108. ISBN 0-903983-87-7. ; summarized at African tripoints: Botswana-Namibia-Zambia by Michael Donner / Jesper Nielsen.
  3. ^ Akweenda, S. (1997-04-23). "VI: Quadripoint Theory". International Law and the Protection of Namibia's Territorial Integrity. Netherlands: Martinus Nijhoff. pp. 201–3. ISBN 90-411-0412-7. 
  4. ^ 49°02′N 87°24′E / 49.04°N 87.4°E / 49.04; 87.4
  5. ^ One such map is at Image:Oceania ISO 3166-1.svg
  6. ^ "Pacific Map, showing EEZ and 12 nautical miles (22 km) zone". SOPAC. http://www.sopac.org/tiki/tiki-map.phtml?mapfile=pacific.map&x=294&y=218&zoom=2&size=600&minx=87.6666666633&miny=-69.7250000024&maxx=277.666666672&maxy=56.9416666698&oldsize=600&EEZ=1&12+miles+zone=1&Country+Names=1&Country+Names_label=1. Retrieved 2006-12-10. 
  7. ^ See The Baarle Enclaves website, including : overview with photograph of the H1-H2 quadripoint and Map including H1 and H2 enclaves
  8. ^ a b Kallos, Aletheia (2006-06-08). "an apparent nose2janontvb binational quadripoint". BoundaryPoint (Yahoo! Groups). http://groups.yahoo.com/group/BoundaryPoint/message/19589?l=1. Retrieved 2006-06-20. 
  9. ^ Schuler, Martin; Pierre Dessemontet, Dominique Joye (July 2005) (in French) (PDF). RECENSEMENT FÉDÉRAL DE LA POPULATION 2000: LES NIVEAUX GÉOGRAPHIQUES DE LA SUISSE. with the collaboration of Manfred Perlik. Neuchâtel: Swiss Federal Statistical Office. pp. 22, fn. 12. http://www.bfs.admin.ch/bfs/portal/fr/index/themen/raum_und_umwelt/uebersicht/blank/publikationen.Document.64477.html. Retrieved 2007-01-04. "Juridiquement ..., un seul point de contact définit la qualité de territoire limitrophe. ... ce point de droit a permis que la commune de Roggenburg puisse changer de canton (d'abord vers Berne, puis vers Bâle-Campagne). De même la commune de Schelten n'est pas considérée comme une exclave du canton." 
  10. ^ Ordnance Survey grid reference for Four Shire Stone: SP231321
  11. ^ Buchanan, C. A.; Robert Angus Buchanan (1980). The Batsford Guide to the Industrial Archaeology of Central Southern England: Avon County, Gloucestershire, Somerset, Wiltshire. Batsford. p. 91. ISBN 0713413646. 
  12. ^ "A real quadripoint?". blanchflower.org. http://www.blanchflower.org/tripoints/quad.html. 
  13. ^ http://www.spc.int/prism/country/NU/stats/Nu_Environment/NU_Land/Stats_Map.jpg
  14. ^ Counties of Florida map from U.S. Census Bureau.
  15. ^ Kuhankuono octopoint from National Land Survey of Finland map
  16. ^ Pöytyän kunta — official website (Finnish)

[edit] See also

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Quadripoint"