Nature’s growth spurt: How mountains like Everest are reaching new heights

Mount Everest is having a growth spurt, but it’s not the only mountain getting taller. The Rocky Mountain ranges we call home, along with the white-capped Everest are still growing. How can something so massive and stoic as mountains continue to grow?
Mount Everest has rightful declared its place as the tallest mountain and highest point on Earth, standing at a staggering 29,032 feet.
According to a modeling study, Mount Everest has grown 50 to 164 feet higher than expected over the past 89,000 years. The surprising cause of this growth is a “river capture event,” a rare occurrence where one river changes course and diverts with another riverbed, stealing its water. This increased flow caused the river to erode the surrounding land, reducing the weight on the Earth’s crust. As a result, a process called isostatic rebound occurred, where the land beneath Everest lifted upward to compensate for the mass lost through erosion, according to The Washington Post.
Matthew Fox, study co-author and geologist at the University College London told The Washington Post, the growth of Mount Everest will persist for millions of years.
“‘It is well established that mountain peaks rise as rivers along intervening valleys erode downward and remove mass from the system,’ said Paul Kapp, geoscience professor at the University of Arizona, who was not involved in the research. The study is ‘novel and exciting’ because it quantifies when, how, and to what extent changes in river drainages contributed to the accelerated uplift, he added,” per The Washington Post.
The “river capture event” accounts for part of the mountain’s growth spurt, but there is more to the additional height. Forty-five million years ago, the Indian and Eurasian tectonic plates collided, forming Mount Everest. This collision continues to push together, causing the entire Himalayan mountain range, including Everest, to rise, according to The New York Times.
The New York Times reported, “But its growth spurt probably won’t continue forever. The balance could tip the other way, shaving some of Everest’s great height. The Himalayas will rise and fall, as all mountain ranges do.”
Just like Everest, the Rocky Mountains and other western ranges are not immune to the geological forces that cause growth. Although the Rockies are considered to be “weird” as they did not form due to tectonic plate boundaries, where plates either collide, move apart, or slide past each other. The Rockies are located in the middle of a stable continent far from any plate boundary, according to the United States Geological Survey.
The USGS reported that an event known as the Laramide Orogeny occurred 70 million years ago, which is believed to have caused the formation of the Rocky Mountains. A small oceanic plate called the Farallon Plate began pushing beneath the North American Plate at a shallow angle. This allowed it to move further inland, causing volcanic activity and pushing up the land to form the Rockies.
“Erosion from glaciers and rivers like the Arkansas and South Platte removed thousands of feet of this less robust sediment, leaving behind the hard basement granites and gneiss that make up the core of the Rockies,” per the USGS.
Although the Laramide Orogeny ended millions of years ago, the Rockies are still slowly growing today. Tectonic forces, combined with erosion, causes the mountains rise slightly in response.
Geologist Patrick Abbot, professor emeritus at San Diego State University, explorer, guide and author of several books said, “Looking closely you can see something of a complex geologic history, the rise and fall of mountains.”