A Himalayan river may be making Everest taller
Mount Everest is 15-50m taller than it would otherwise be because a river is eroding rock and soil at its base, helping push it upwards, according to a new study.
Loss of landmass in the Arun river basin 75km (47 miles) away is causing the world’s highest peak to rise by up to 2mm a year, University College London (UCL) researchers said.
“It’s a bit like throwing a load of cargo off a ship,” study co-author Adam Smith told the BBC. “The ship becomes lighter and so floats a little higher. Similarly, when the crust becomes lighter… it can float a little higher.”
Pressure from the collision of the Indian and the Eurasian plates 40-50 million years ago formed the Himalayas and plate tectonics remains the major reason for their continued rise.
As the Arun flows through the Himalayas it carves away material – the river bed in this case - from the Earth's crust. This reduces the force on the mantle (the next layer under the crust), causing the thinned crust to flex and float upward.
