Mount Everest is growing a bit faster than usual. And a 'river capture' may have to do with it

Mount Everest has been growing taller slowly over the years and that's not news, as the mountain was created when two tectonic plates crashed into each other over millennia. But a new study has suggested that there's a relatively sudden growth spurt in the world's tallest peak, and this time it's being attributed to "river piracy".

The study published in Nature Journal examined GPS measurements over the years to reach a conclusion. It found that Everest, also known as Chomolungma or Sagarmatha, was growing at 0.08 inches or 2 millimetres per year, as opposed to the regular 0.04 inches or 1mm per year.

The study by University College London researchers said it "uncovers a previously unrecognised, additional mechanism of rock uplift active since river capture."

Add WION as a Preferred Source

While Everest is 8,849 metres tall, the nearby peak K2 is 8,611 m. The other three highest mountains in the Himalayas stand at 8,586 m, 8,516 m and 8,485 m, an elevation difference of not more than 100 m.

The researchers suggest that it could be because rocks below the mountain base are being eroded over the years by the rivers flowing in the area.

In science-speak, it is a phenomenon of'river drainage piracy' and 'river capture'.

The erosion of the rocks appears to affect the nearby peaks more than Mount Everest.

It is being caused by the merging of two rivers down below that happened tens of thousands of years ago.

Watch: Everest faces the challenge of overcrowding, commercialisation hits Mount Everest hard

The river capture that may be helping Everest grow

The 'river capture event' happened in the Kosi River drainage basin some 89,000 years ago. Kosi merged with its tributary Arun River and changed course.

The researcherschasing the question, 'Is there an underlying mechanism raising Everest ever higher?' looked for answers insurrounding rivers.

The Arun Riverdrains a large area to the north of the Everest region before turning south.

To reach their conclusion, the scientists reconstructed the capture process using computer models.

"Our best-fit model suggests the capture event occurred approximately 89,000 years ago and caused acceleration of downstream incision rates," wrote the researchers in the study.

"We suggest that part of Chomolungma [Everest]’s anomalous elevation (~15–50 m) can be explained as the isostatic response to capture-triggered river incision, highlighting the complex interplay between geological dynamics and the formation of topographic features," said the study.