The summit of Chimborazo, a volcano in Ecuador, is two kilometres farther from the Earth’s centre than Mount Everest.
Earlier this week, writing about the highest mountain in the solar system, I was thinking about Mount Everest. It is one of the world’s most famous records, the highest peak on the planet. But it holds this title solely because of how we define height – as it relates to mountains, anyway.
Everest is the highest point in the world above sea level. If you ignore sea level and instead measure height from the base of a mountain to its top, Mauna Kea is taller than Everest. That Hawai’ian volcano is more than 10 kilometres tall, more than a kilometre more than our highest mountain. Mauna Kea doesn’t get the credit because most of that 10 kilometres is underwater. But that’s still not the highest mountain.
Chimborazo is a beautiful volcano in Ecuador, part of the Andes mountain range. Measure its height from sea level and you get a respectable but unremarkable 6263 metres. There are more than a hundred higher mountains, including thirty-eight in the Andes alone. But Chimborazo has one unique property: it is exceptionally close to the equator.
Why does this matter? Well, it matters because the Earth is not round. Like a certain 2020 presidential candidate, it is flattened at the poles. The Earth bulges out at the equator because of the planet’s rotation and gravity. Sea level bulges out at the equator too, so if you use that as the basis of your measurement the equatorial bulge doesn’t make a difference. However, if you instead define height as the distance from the centre of the Earth, a mountain on or near the equator is going to be higher than one further north or south.
Everest is 6382 kilometres from the centre of the Earth. Chimborazo is 6384 kilometres from the centre of the Earth – more than two kilometres more. Depending on your definition, Chimborazo is the highest mountain on the planet.