New study reveals Mount Everest 15‑50 metres higher than previously thought
According to new research, Mount Everest is 15-50 metres taller. This is most likely due to a Himalayan river, which causes erosion of rocks and soil at its base, helping to push it up. Does this mean we will soon revise its height of 8,848 metres in atlases?
The loss of land mass in the Arun river basin, 76 kilometres away, causes the world's highest peak to rise even up to 2 millimetres annually, claim scientists from University College London (UCL). "It's a bit like dropping cargo from a ship," explains Adam Smith, co-author of the study, as quoted by the BBC. "The ship becomes lighter and floats a little higher. The same happens to the crust when it becomes lighter... it can float a little higher," he added.
The pressure caused by the collision of the Indian and Eurasian plates 40-50 million years ago formed the Himalayas, and plate tectonics remains the main reason for their continued growth. The latest research results indicate that the Arun river network is another factor contributing to the growth of the mountains.
This is an effect called isostatic rebound. The study, published in Nature Geoscience, adds that this upward force causes Everest and other neighbouring peaks, including the fourth and fifth highest peaks in the world, Lhotse and Makalu, to rise.
Mount Everest and neighbouring peaks grow because isostatic rebound lifts them faster than erosion wears them down, said study co-author Dr Matthew Fox to the BBC. "We see them growing by about 2 millimetres annually through GPS instruments, and now we understand better what drives this growth," he added.
Mount Everest is getting taller
Everest stands on the border of China and Nepal, with its northern part on the Chinese side. The Arun river flows from Tibet to Nepal and then joins two other rivers, forming the Kosi river, which is a left tributary of the Ganges. According to UCL scientists, the river likely gained its true "lifting" power when it "captured" another river or water body in Tibet 89,000 years ago, which is quite recent in geological time.
The changing height of Mount Everest truly highlights the dynamic nature of the Earth's surface, he said.
UCL's study showed that the Arun river most likely gained the ability to carve out an extraordinary amount of rock and other materials after it captured another river or water system in Tibet. Many geologists, both those involved and not involved in the research, stated that the theory is credible but requires even more precise studies.
