Confluence point
A point of confluence (from Latin confluere , to flow together ) is the intersection of an integral longitude with an integral latitude on the surface of the earth.
Number and location
In the coordinate system of the earth there are 180 degrees of latitude and 360 degrees of longitude, whereby the two 90th degrees of latitude, the geographic poles , are point-shaped and only count as one point of confluence. To the remaining 178 degrees of latitude, the equator has to be added as the zero degree of latitude. These 179 non-point latitudes each form 360 points of confluence. With the two poles there are arithmetically 64,442 confluence points. 21,543 of these points are on land, 38,409 on ocean surfaces and 4,490 in the area of the polar ice caps.
The maximum distance of any point on the earth's surface to the nearest point of confluence is about 79 kilometers. Since these are purely virtual points, their exact location in the terrain depends on the reference system used. As a rule, points of confluence are specified in accordance with WGS84 , which is also the basis for determining the GPS position.
Confluence points in Germany
There are 48 confluence points within the German territory, two of which are in built-up areas:
- 50 ° 0 ′ 0 ″ N , 8 ° 0 ′ 0 ″ E inWinkel (Rheingau)
- 48 ° 0 ′ 0 ″ N , 10 ° 0 ′ 0 ″ E inred on the Rotmountain
Four more are in the North or Baltic Sea, the remaining 42 in the area.
At Arnstein in Lower Franconia , the 10th degree of longitude intersects the 50th degree of latitude and forms the only point of confluence between a main latitude and a main longitude in Germany. In 1990 a meridian monument was erected around 200 m south of it on a dirt road parallel to the B 26a .
The intersection of the 6th degree of longitude and the 51st degree of latitude is on the northern edge of the main town of Gangelt , North Rhine-Westphalia . The Mercator Point was built here. This monument commemorates the geographer and cartographer Gerardus Mercator (1512–1594), who grew up in Gangelt from 1512 to 1518.
Degree Confluence Project
The Degree Confluence Project aims to document every point of confluence on earth by means of a personal visit. The project participants put an illustrated report on the project pages on the Internet for each point of confluence they visited. Not only the first visit to a confluence point is registered, but also all further visits in order to document long-term changes to the points. The visitors should not change anything at the location of the point.
In the interests of balance, the project distinguishes between “primary” and “secondary” points of confluence; priority should be given to the primary points. As a result, on the one hand, points on land are preferred to those on the open sea, on the other hand, the increasing density of points on circles of latitude far from the equator is compensated for. For example, only two thirds of the points are assumed to be primary on the 49th parallel and only ten points on the 89th parallel. WGS84 , which is standard in most GPS devices, is used as the reference system .
Of the 16,347 primary confluence points (14,029 on land, 2,167 on the water and 151 in the area of the polar ice caps), 6,343 in 182 different countries have been successfully visited at least once (as of April 2015). This corresponds to a share of 38.8%. In addition, 1,313 secondary points of confluence were documented. If one adds the multiple visits to the same confluence points, the result is a number of 15,122 documented visits by a total of 12,786 visitors. The number of published images is 110,447.
Similar projects
Remarks
- ↑ Example: Saudi Arabia and Greenland each have the same land area with around 2 million km 2 . While Saudi Arabia contains 181 confluence points, there are 815 in the far north of Greenland. According to the assessment, all points are primary in Saudi Arabia, and 300 in Greenland.
Web links
swell
- ^ History of the Gangelt community. In: gangelt.de. Retrieved July 29, 2020 .
- ^ R. Mautz: Sampling the World. ( Memento of the original from July 6, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 6.9 MB) In: Coordinates - Positioning, Navigation and Beyond. No. 3, 2008, pp. 22-27. (English)
- ↑ statistics page (English)
