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Mount Everest May Have Suddenly Changed Height

author

Robin Andrews

Science & Policy Writer

clockJan 26 2017, 10:41 UTC

You sneaky mountain, you. Daniel Prudek/Shutterstock

We’re not sure yet, but Mount Everest may have shrunk a little – or grown a little – and both Nepalese and Indian authorities are investigating.

According to Surveyor-General Swarna Subba Rao, India’s central mapping agency will send an expedition to the highest peak on Earth to double-check whether or not it lost or gained a little bit of elevation as a consequence of recent tectonic activity in the region.

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“We don't know what happened, there's been no confirmed report,” Rao told BBC News. “Some scientists do believe it has shrunk. But there's a school of thought it may have grown.”

In order to check, GPS measurements and detailed cartography will be carried out in a couple of months at the most before the final result is declared.

Currently, Everest is thought to be 8,848 meters (29,028 feet) above sea level. The change in height, whichever way it goes, will likely only be a few centimeters, if that.

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But wait – how on Earth do mountains suddenly change height? Well, apart from being slowly eroded from the top down over time, all it takes is a powerful enough earthquake.

The devastating April 2015 earthquake in Nepal, registering as a 7.8M event, may have just been powerful enough. Within just 45 seconds, a 30-kilometer (18.6-mile) stretch of the Main Himalayan Thrust – the slipping fault line in question – moved eastwards at speeds of up to 3 kilometers (1.9 miles) per second.

As expected, this caused quite a significant amount of land relief change. Some parts of the region sank into the ground, whereas others moved skywards. Some sections moved vertically by around 9 meters (roughly 30 feet).

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There was plenty of lateral movement too. Kathmandu, the capital city, moved from its original spot by about 3 meters (nearly 10 feet).

At the time, satellite measurements seemed to show that there had been no change in the height of Everest, but for some unexplained reason, experts are now beginning to suspect this was wrong.

Still, we don’t know whether or not there has been a change, or what precisely the change has been. So the story at present is that – to be honest with you – we have no idea what’s going on. Sorry.


natureNature
  • tag
  • earthquake,

  • mountain,

  • Himalayas,

  • India,

  • height,

  • nepal,

  • mount everest,

  • April 2015