Tide gauges measure water levels. People started installing tide gauges in harbors in the 19th century. There are tide gauges all over the world, but they are not spread evenly, and this is a problem. The Permanent Service for Mean Sea Level, which compiles tide gauges from governments across the world, recognizes fewer than 20 active stations on the entire African continent. Their map looks a little like the map of long-running tide gauges: concentrated in Europe, the United States, Japan and a few of the other “developed” regions of the world.

Source: The North Africa Journal February 05, 2020 09:11 UTC