The Equatorial Bulge

Mount Cotopaxi in Ecuador (19,347 Feet or 5,897 Meters)

The Earth is by no means a perfect sphere. If you are standing at either the North or South Pole, you are some 21 km nearer to the center of the planet than if you were near the Equator. The reason for this is that the rotation of the planet exerts a centrifugal force that makes of the Earth more of an oblate ellipsoid. The illustration below exaggerates this phenomenon, but gives you the general idea:

Earth as an Oblate Ellipsoid

One upshot of this phenomenon is that some of the mountains nearer the Equator are actually higher than any of the Himalayas, including Mount Everest. The so-called Equatorial Bulge calls for a more accurate measure of a mountain’s altitude than distance above sea level—especially as the bulge means that sea level is correspondingly higher. A more accurate measure is distance from the center of the Earth.

Using this measure, Mount Everest just barely makes the top ten list:

The Highest Mountains on Earth Measured by Distance from the Earth’s Center

According to this chart, the highest mountain is a virtual tie between Chimborazo in Ecuador and the South Summit of Huascarán in Peru. In fact, by this measure eight of the ten highest mountains in the world are in the Andes, the only exceptions being Kilimanjaro in Tanzania and Everest in Nepal.

Tomorrow, I will repost a blog I wrote about my visit to Mount Chimborazo in 2016.