A few hundred miles off the west coast of Africa, in the Gulf of Guinea, a lonely weather buoy bobs up and down the ocean waves. Code named Station 13010-Soul, this moored observation buoy is one of numerous that make up the “Prediction and Research Moored Array in the Tropical Atlantic”, in short PIRATA—a system developed jointly by the US, Brazil and France to study ocean-atmosphere interactions in the tropical Atlantic. Data collected by the PIRATA array helps scientists better understand the climate of tropical Atlantic which in turn helps them improve weather forecasting and climate research worldwide. Alongside the RAMA array in the Indian Ocean and the TAO/TRITON network in the Pacific Ocean, PIRATA forms part of the worldwide system of tropical ocean observing buoys.

National Data Buoy Centre weather buoy Station 13010-Soul.

So what’s special about Station 13010-Soul?

Station 13010-Soul is moored exactly where the Equator intersects the Prime Meridian. Its coordinates are therefore 0,0—zero longitude and zero latitude. This place has actually little geographic significance because there is nothing out there except water, but as far as digital geospatial data is concerned, coordinates 0,0 may be one of the most geo-tagged places on Earth.

When addresses are added to a map, a program called a geocoder translates the physical address into its geographic coordinates, which allows the location to be easily mapped. But sometimes due to human typos, bad data or even bugs in the geocoder itself, the geocoding program fails to run correctly and the output of the program becomes “0,0”—or no information. You might have come across this bug more often than you realize, for example, while taking a photo with your smartphone camera. If the camera software has the geo-tagging feature disabled, it will tag the photo with null values for both latitude and longitude.

Trouble begins when another program tries to read this data. A properly designed software will identify the values as invalid and ignore them, but badly written ones will map them to this lonely spot hundreds of miles from the shores of Africa. Because there are scores of badly written software using map data, an unbelievably large number of addresses get mapped to this fictional place called “Null Island” out in the Atlantic. The term was coined in 2011 by authors of Natural Earth, a public domain map dataset, describing it as “a one meter square island”. Since then, Null Island has become a geographer’s inside joke. Later, someone put up a website—www.nullisland.com (it’s unavailable now) for the “Republic of Null Island” and gave it a fictional history, a flag and a map.

Null Island isn’t the only product of geocoding errors. Nathaniel Vaughn Kelso and Tom Patterson, the original discoverers of Null Island, noted that Null Island-like anomalies exist for all local coordinate reference systems besides WGS 84. Kenneth Field, a British cartographer, hunted down all Null Islands, Null Lakes and even Null Black Holes (coordinate pairs that fall outside of the coordinate domain) for more than 5,700 different coordinate systems and plotted them on a single map to explore. He collectively refers to them as Nill Points.

Interests in Null Island, however, is more than academic. A cautionary tale about creating custom Null Islands once made the news when developers of the Los Angeles Police Department’s crime mapping software created a default address around the corner from the City Hall. This caused all undecipherable addresses to be mapped to that particular location, thus artificially boosting crime rates in the area. The issue went on for years until it was fixed in 2011.