Mount Everest no longer world’s highest mountain

Monday, 8th February 2010 by

Which is closer to the surface of the moon, the summit of Mount Everest or Ecuador?

Contrary to popular belief, the answer is Ecuador, as the Earth isn't a perfect sphere. As the Earth is constantly spinning, centrifugal force causes it to bulge out at the equator much like a water balloon would if you placed it on a table and pressed on the top.

The Earth's shape: An Oblate Spheroid

Let's look at Mount Chimborazo in Ecuador. The summit of Chimborazo is 6,267 m (20,561 ft) above sea level, which is quite large but not quite the highest mountain in the Andes. If you take into account the Earth's equatorial bulge, a straight line from the summit down to the estimated centre of our planet would be 6,384.4 km (3,967.1 mi).

Mount Chimborazo Mount Chimborazo

Now look at Mount Everest, widely known as the tallest mountain in the world. The summit of Everest is 8,848 m (29,029 ft) above sea level, but a straight line from the summit to the centre of the Earth would only be 6,382.3 km (3,965.8 mi).

Mount Everest Mount Everest

So even though the summit of Chimborazo is about 2,400 m closer to sea level than Everest, it's still 2,100 m further away from the centre of the Earth! By this logic, three more mountains (Huascaran, Cotopaxi and Kilimanjaro) around the world are actually "higher" than Everest as well.

Mount Huascaran Mount Kilimanjaro

Sadly our newly defined rules aren't taken into account when deciding on the world's highest mountain, so although Chimborazo is ranked the highest in distance from the centre of the Earth, Mount Everest still wins since we always measure to sea level.

If you're a climber and neither one these appeals, you could always try Gangkhar Puensum in Bhutan. It's considered the highest unclimbed mountain in the world1.

Gangkhar Puensum Gangkhar Puensum

  1. Which is probably something to do with the fact that climbing mountains higher than 6000 m in Bhutan has been prohibited since 1994, out of respect for local spiritual beliefs. ↩︎