geography Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...

, the

centroid In mathematics and physics, the centroid, also known as geometric center or center of figure, of a plane figure or solid figure is the arithmetic mean position of all the points in the figure. The same definition extends to any object in n-d ...

of the two-dimensional shape of a region of the Earth's surface (projected radially to sea level or onto a

geoid The geoid ( ) is the shape that the ocean surface would take under the influence of the gravity of Earth, including gravitational attraction and Earth's rotation, if other influences such as winds and tides were absent. This surface is exte ...

surface) is known as its geographic centre or geographical centre or (less commonly) gravitational centre. Informally, determining the centroid is often described as finding the point upon which the shape (cut from a uniform plane) would balance. This method is also sometimes described as the "gravitational method". One example of a refined approach using an azimuthal equidistant projection, also potentially incorporating an iterative process, was described by Peter A. Rogerson in 2015. The abstract says "the new method minimizes the sum of squared great circle distances from all points in the region to the center". However, as that property is also true of a centroid (of area), this aspect is effectively just different terminology for determining the centroid. In 2019, New Zealand's

GNS Science GNS Science (), officially registered as the Institute of Geological and Nuclear Sciences Limited, is a New Zealand Crown Research Institute. It focuses on geology, geophysics (including seismology and volcanology), and nuclear science (partic ...

also used an iterative approach (and a variety of different projections) when determining a centre position for New Zealand's

Extended Continental Shelf The extended continental shelf, scientific continental shelf, or outer continental shelf, refers to a type of maritime area, established as a geo-legal paradigm by the United Nations Convention on the Law of the Sea (UNCLOS). Through the process kno ...

. However, other methods have also been proposed or used to determine the centres of various countries and regions. These include: * centroid of volume (incorporating elevations into calculations), instead of the more usual centroid of area as described above. * centre point of a

bounding box In geometry, the minimum bounding box or smallest bounding box (also known as the minimum enclosing box or smallest enclosing box) for a point set in dimensions is the box with the smallest measure (area, volume, or hypervolume in higher dime ...

completely enclosing the area. While relatively easy to determine, a centre point calculated using this method will generally also vary (relative to the shape of the landmass or region) depending on the orientation of the bounding box to the area under consideration. In this sense it is not a robust method. * finding the longitude that divides the region into two equal area parts to the east and west, and then similarly the latitude that divides the region into two equal area parts to the north and south. Like the bounding box approach described above this method would not generally locate precisely the same point if the same shaped region was oriented differently. As noted in a

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

document, "There is no generally accepted definition of geographic center, and no completely satisfactory method for determining it." In general, there is room for debate around various details such as whether or not to include islands and similarly, large bodies of water, how best to handle the curvature of the Earth (a more significant factor with larger regions) and closely related to that issue, which

map projection In cartography, a map projection is any of a broad set of Transformation (function) , transformations employed to represent the curved two-dimensional Surface (mathematics), surface of a globe on a Plane (mathematics), plane. In a map projection, ...

to use.

Notable geographical centres

Geographical centre of Earth The geographical centre of Earth is the geometric centre of all land surfaces on Earth. Geometrically defined it is the centroid of all land surfaces within the two dimensions of the Geoid surface which approximates the Earth's outer shape. The t ...

Axis mundi In astronomy, is the Latin term for the axis of Earth between the celestial poles. In a geocentric coordinate system, this is the axis of rotation of the celestial sphere. Consequently, in ancient Greco-Roman astronomy, the is the axis of ...

Omphalos of Delphi The Omphalos of Delphi is an ancient marble monument that was found at the archaeological site of Delphi, Greece. According to the Ancient Greek myths regarding the founding of the Oracle of Delphi, Delphic Oracle, the god Zeus, in his attempt ...

Geographic centres in Africa

Geographic Centre of Uganda (Amolatar Monument) The geographic centre of Uganda is north of Lake Kyoga in Olyaka village, Olyaka parish in Namasale sub-county in Amolatar District, Northern Uganda. The point is marked by the Amolatar Monument aka Uganda Tribes Monument which displays the n ...

Geographic centres in Asia

* Geographical midpoints of Asia, in

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

* Geographical centre of India **

Zero Mile Stone (Nagpur) Zero Mile Stone (ISO: ''Śūnya Mailācā Dagaḍa'') is a monument built by the British during the Great Trigonometrical Survey of India in 1907 in Nagpur, Maharashtra. The Zero Mile Stone consists of a pillar made up of sandstone and another ...

* Geographic center of Iran * Geographic centre of Sri Lanka * Geographical centre of the Korean Peninsula * Geographical centre of the Philippines * Geographical centre of the Russian Federation * Geographical centre of the Soviet Union * Geographic center of Taiwan

Geographic centres in Europe

Geographical midpoint of Europe The location of the geographical centre of Europe depends on the definition of the borders of Europe, mainly whether remote islands are included to define the extreme points of Europe, and on the method of calculating the final result. Thus, sev ...

* Geographical centre of Austria *

Geographic center of Belarus The geographical center of Belarus () is at the geographical coordinates of latitude 53°31'44.54", longitude 28°02'41.90". It is located 70-km south-east of Minsk, a 6-km west of Marina Hills, and 1 km to the south-east of the village An ...

* Geographical centre of Belgium (Nil-Saint-Vincent-Saint-Martin) * Geographical centre of Estonia (Paenasti) * Geographical centre of Germany (Niederdorla) **

Central Germany (geography) Central Germany () or Middle Germany ( ), in geography, describes the areas surrounding the geographical centre of Germany. Hesse, Saxony-Anhalt and Thuringia are the only landlocked German states without an international border except for ...

* Geographical centre of Hungary (Pusztavacs) *

Geographical centre of Ireland The Geographical Centre of Ireland, according to an investigation and calculation carried out by the Official Irish Government Mapping Agency, Ordnance Survey Ireland (OSI) published on the official OSI website on 24 February 2022 is near the ...

* Geographical centre of Lithuania (Ruoščiai) * Geographical centre of Norway * Geographical centre of Poland * Geographical center of Romania (Făgăraș) * Geographical centre of the Russian Federation (Lake Vivi) * Geographical centre of Serbia (Drača) * Geographical centre of Slovenia * Geographical centre of the Soviet Union * Geographical center of Spain (Cerro de los Ángeles) *

Geographical center of Sweden The geographical center of Sweden is contested amongst at least four locations. Flataklocken The oldest and most famous geographical center of Sweden is Flataklocken, a spot next to Lake Munkby in Torpshammar, Medelpad at . The site was identif ...

* Geographical centre of Switzerland *

Centre points of the United Kingdom There has long been debate over the exact location of the geographical centre of the United Kingdom, and its constituent countries, due to the complexity and method of the calculation, such as whether to include offshore islands, and the fact t ...

** Geographical centre of Great Britain (Brennand Farm) ** Geographic centre of England **

Geographical centre of Scotland There is some debate as to the location of the geographical centre of Scotland. This is due to different methods of calculating the centre, and whether surrounding islands are included. Centre of gravity method In 2002, the Ordnance Survey calc ...

** Geographic centre of Wales (Cwmystwyth)

Geographic centres in North America

* Geographic center of North America * Geographic centre of Canada * Geographic center of the United States **

List of geographic centers of the United States This is a list of Geographical centre, geographic centers of each U.S. state and inhabited Territories of the United States, territory. The geographic center of the United States is northeast of Belle Fourche, South Dakota, Belle Fourche in Butte C ...

Geographic centres in Oceania

Centre points of Australia Centre points of Australia are those geographical locations that have been considered to be ''centre'' of Australia, as distinct from the extreme points of Australia. Finding the centre point John McDouall Stuart wrote "Sunday, 22 April 1860, ...

* Geographic centre of New Zealand

Geographic centres in South America

* Geographical Center of South America * Geographical Center of Colombia

References

External links

* {{Set index article