The Himalayan mountain range is getting taller all the time, as the Indian tectonic plate continues to crash into the Eurasian plate. That's been going on for millions of years. Mount Everest, at 29,032 feet, is the tallest of the Himalayas, and indeed it is the highest point on earth. But Everest is growing faster in relation to the mountains around it, by about two millimeters a year. Why is that?
Scientists have determined that it is because of isostatic rebound caused by a river 47 miles away from the mountain. The Arun River carries away a lot of material that erodes from Everest. You'd think that erosion would make the mountain smaller, but the effect is just the opposite. The authors of a new study explain isostatic rebound by comparing the earth's crust to a cargo ship being unloaded, or a couch cushion when you stop sitting on it. There are also glaciers involved, and the same effect explains why sea levels are rising faster in New York City than in other places in the world. Read about the forces that are making Mount Everest grow taller faster than the other Himalayan mountains at Smithsonian. Personally, I'm still wondering who gets the job of climbing Mount Everest with a tape measure every year.
(Image credit: Nir B. Gurung)