Posts Tagged ‘degree confluence’

Degrees Confluence Project

Wednesday, October 22nd, 2008

[Editor's note: Fun project just a little larger in scope than visiting every continent or country or U.S. county. Check out pictures from around the world. All content below from confluence.org. Thanks Mary Ellen!]

The goal of the Degrees Confluence project is to visit each of the latitude and longitude integer degree intersections in the world, and to take pictures at each location. The pictures, and stories about the visits, will then be posted at the site.

Overview

The project is an organized sampling of the world. There is a confluence within 49 miles (79 km) of you if you’re on the surface of Earth. We’ve discounted confluences in the oceans and some near the poles, but there are still 10,809 to be found.

In our case a degree confluence is the exact spot where an integer degree of latitude and an integer degree of longitude meet, such as 43°00’00″N 72°00’00″W. The project uses the WGS84 datum to define the confluence location.

18 newest confluence visits Newest Confluence Visits RSS feed (view on Google Maps)
The date the confluence is posted to the site is used to determine the newest confluence visits.

36°N 56°E preview image 36°N 56°E
7.9 km (4.9 miles) SE of Gīvar, Semnān, Iran
[20-Oct-08]
57°N 15°E preview image 57°N 15°E
2.0 km (1.2 miles) W of Skårtaryd, Kronoberg, Sweden
[20-Oct-08]
56°N 110°E preview image 56°N 110°E
8.3 km (5.2 miles) NW of Kichera, Respublika Buryatiya, Russia
[incomplete] [secondary] [19-Oct-08]
44°N 7°E preview image 44°N 7°E
1.3 km (0.8 miles) E of Rigaud, Alpes-Maritimes, Provence-Alpes-Côte d’Azur, France
[19-Oct-08]
52°N 14°E preview image 52°N 14°E
2.9 km (1.8 miles) NE of Märkische Heide-Biebersdorf, Brandenburg, Germany
[secondary] [19-Oct-08]
53°N 6°E preview image 53°N 6°E
1.9 km (1.2 miles) N of Langezwaag, Friesland, Netherlands
[19-Oct-08]
46°N 1°W preview image 46°N 1°W
3.2 km (2.0 miles) NE of Saint-Laurent-de-la-Prée, Charente-Maritime, Poitou-Charentes, France
[19-Oct-08]
55°N 83°E preview image 55°N 83°E
3.7 km (2.3 miles) WSW of Razdol’noye, Novosibirskaya oblast’, Russia
[secondary] [19-Oct-08]
43°N 80°W preview image 43°N 80°W
6.9 km (4.3 miles) NE of Hagersville, ON, Canada
[18-Oct-08]
34°N 106°W preview image 34°N 106°W
9.8 miles (15.8 km) S of Claunch, Socorro, NM, USA
[15-Oct-08]
45°N 123°W preview image 45°N 123°W
3.8 miles (6.1 km) NNE of Salem, OR, USA
[incomplete] [15-Oct-08]
35°N 117°W preview image 35°N 117°W
7.3 miles (11.8 km) N of Barstow, San Bernardino, CA, USA
[15-Oct-08]
53°N 88°E preview image 53°N 88°E
6.0 km (3.7 miles) NNW of Sheregesh, Kemerovskaya oblast’, Russia
[13-Oct-08]
54°N 61°E preview image 54°N 61°E
3.8 km (2.4 miles) ESE of Belyy Klyuch, Chelyabinskaya oblast’, Russia
[12-Oct-08]
57°N 35°E preview image 57°N 35°E
0.9 km (0.6 miles) ENE of Dubrovka, Tverskaya oblast’, Russia
[secondary] [12-Oct-08]
54°N 109°E preview image 54°N 109°E
18.8 km (11.7 miles) N of Angakan, Respublika Buryatiya, Russia
[12-Oct-08]
53°N 108°E preview image 53°N 108°E
15.5 km (9.6 miles) WNW of Turka, Respublika Buryatiya, Russia
[12-Oct-08]
21°N 86°E preview image 21°N 86°E
9.4 km (5.8 miles) ENE of Sukinda, Orissa, India
[11-Oct-08]

Information about a Confluence
Initially, the information in our database about confluences was entered both manually, and by extracting data from various sources. Since then, there have been various updates, both manual and automated, and when someone finds an error and lets us know, we make the correction. Some confluences have been added or changed, where they were in the oceans but a mathematical model shows that they should have a view of land. The altitude listed for a confluence usually comes from a digital elevation model, and may not be accurate. The data used to make the distinction between ‘Water’ and ‘Ice Cap’ may not be accurate, and polar ice caps change over time. If you know of some confluence data that needs correcting, please advise the regional coordinator for the area.

We have two sets of confluence information in our database. For all of the 64,442 possible degree confluences, we have some basic information. For the 24,623 degree confluences that we have “indexed”, we have additional information, such as the nearest town, and we have assigned the confluence to a ‘geographic area’, such as a Country.

Land, Water, Ice
All of the 64,442 possible confluences have been assigned to one of three categories – Land(21,543), Water(38,409), or Ice Cap(4,490). Confluences that are on ‘Land’ are those that our data shows as being located on a continent or an island. The presence of ice doesn’t change that. A confluence on a lake doesn’t change it’s status if the lake freezes over in the winter. A confluence located on a glacier is considered to be on land. Confluences not on ‘Land’ are on ‘Water’, except for areas with permanent ice, which are categorized as ‘Ice Cap’, such as confluences near the North Pole.

Primary vs Secondary
A confluence is primary if:

  1. It meets the criteria outlined in the Poles Problem section.
  2. It is on land, or if on a body of water or on an ice cap, within sight of land, so that on a clear day discernable land features can be recognized.

All other confluences are defined as secondary. They will be accepted if visited but are not part of the primary goals of the project. Note that ANY visited confluence, regardless of whether it is primary or secondary, will be added to the site, even if it is not currently indexed in our database.

Changes in the Confluence type
There are 39,819 confluences that are not “indexed” in our database, because they lie in the oceans, are presumed to not have a view of land (are more than 5 kilometers from land), and are unlikely to be visited. An unindexed confluence is presumed to be Secondary, and will be added to our database if visited.

A Primary confluence would be changed to Secondary if a visit shows that there is no view of land on a clear day. This would include a visit to a confluence on a large lake. A confluence that is Secondary because it is “on the water” and is presumed to have no view of land would be changed to Primary if a visit shows a view of land, but only if it qualifies based on the Poles Problem logic.

Confluences on borders
Confluences exactly on the Northern and Eastern borders of a state, province or country will be included in that state, province or country. Confluences on the Southern and Western borders will be included in the bordering state, province or country.

Historically, borders were defined by a variety of methods, and most that refer to specific coordinates were done long before the WGS84 system was defined. As a result, sometimes the above rule isn’t needed for “border confluences”. For example, the Canada/United States border, from 123°W on the the west coast to 96°W between Manitoba and Minnesota, when viewed using WGS84 coordinates, is actually a line that zig-zags back and forth across the 49th parallel. None of the confluences along the border are actually on the border, so they belong to the province/state in which they are located. If this part of the Canada/United States border was defined as the WGS84 49th parallel, then the above rule would apply, and all these confluences would belong to the United States. See the Canada page for more information.

Poles Problem

If the Earth were a perfect sphere, the north-south distance between adjacent pairs of degrees of latitude (parallels; lines that run east-west) would be the same from the equator to the poles. However, the east-west distance between adjacent pairs of degrees of longitude (meridians; lines that run north-south) varies depending on the latitude, with the maximum distance being at the equator, and the minimum distance being at the poles, where the lines of longitude meet.

Because of the closeness of the degrees of longitude lines towards the poles, we designed a scheme that deals with this skewing of the collection of degree confluences towards the poles. The scheme designates every degree confluence as either Primary or Secondary. While Secondary confluences will be accepted if visited, they are not part of the primary goals of the Degree Confluence Project.