Pathways: Lat & Long

The world is littered with imaginary lines: the Equator, the Prime Meridian, the International Date Line, the tropics, the polar circles, the Paris Meridian, the American Meridian – all are based on the basic grid of latitude and longitude that we are so used looking at on maps. There are, however, two imaginary lines that are incredibly fascinating but little acknowledged.

The two lines you see crossing each other at the Equator and touching again at the poles in a figure-eight are the lines of equal latitude and longitude (really, it’s just one line that loops, but it’s easier to deal with by referring to it as two).Each point in the line represents a spot where the degree value of the line of latitude is the same as that of the corresponding line of longitude (e.g. 33.313°N, 33.313°W). Because of the nature of geographic coordinates (there are distinct locations for 90°N and 90°s, but 180°W and 180°E are one and the same), the lines of equal latitude and longitude only occur on one side of the Earth, necessarily centred around the Prime Meridian (0°).

The lines cross 19 different countries: 13 in Africa, 5 in Eurasia, and Canada. They also, of course, traverse Antarctica across the South Pole. Surprisingly few cities lie directly on the lines; Batumi, Georgia on the Black Sea and Hibberdene, KwaZulu-Natal on the Indian Ocean in South Africa being the most notable. There are a few significant near-misses including Maseru, Lesotho; Abidjan, Cote d’Ivoire; Abuja, Nigeria; Cairo, Egypt; and Orenburg, Russia.

The most interesting fact about the lines of equal latitude and longitude may be the utter lack of awareness of it: a Google search only brings up the Wikipedia article and links to said article. At least when it comes to the intersections of primary degree confluences of equal value (e.g. 6°N, 6°E, 7°N, 7°E, etc.), we can turn to the always informative Degree Confluence Project for information).