Top of the world just got higher
The world’s tallest mountain is now officially taller after China and Nepal remeasured Mt Everest.
New calculations put the top of the world 86cm (34in) higher than previously recognised, measuring in at 8848.86 m (29,032 ft).
The joint declaration by the two national survey teams also settled a long-standing disagreement between neighbouring China and Nepal on the height of Everest.
Until this week, Nepal had judged the mountain to be 8848m, while China thought it was four metres shorter.
Both sides decided to check its height after speculation that a 2015 earthquake had shifted tectonic plates under Everest and that global warming may have thinned snow caps.
Nepal planned to conduct the survey alone, but a joint project was convened under the banner of ‘‘eternal friendship’’ after Xi Jinping, the Chinese president, visited the nation in 2019.
Nepalese surveyors climbed the mountain more than a year ago to take new measurements, in the first such expedition by the nation.
Chinese surveyors made their ascent in May 2020, becoming the only team to reach Everest’s summit this year after the coronavirus pandemic closed the mountain.
The teams used a mixture of GPS data and trigonometric calculations from lower mountains for the new estimate.
‘‘Once the surveyor’s beacon had been placed on the summit, surveyors at stations around the summit measured the distance from the six points to the beacon, which meant at least six triangles could be calculated to determine the mountain’s height,’’ Jiang Tao, an associate researcher at the Chinese academy of surveying and mapping, told the staterun China Daily.
Nepal had previously relied on a 1954 measurement by the Survey of India, but this time conducted its own measuring. Its surveyors had to spend two years training for the dangerous ascent.
‘‘Before this, we had never done the measurement ourselves,’’ Damodar Dhakal, a spokesman at Nepal’s department of survey, told the BBC. ‘‘Now that we have a young, technical team [who could also go to the Everest summit], we could do it on our own.’’
Khimlal Gautam, Nepal’s lead surveyor, lost a toe to frostbite while on the summit to install equipment. ‘‘For summiteers, scaling the highest peak means a great accomplishment. For us, it was just the beginning,’’ he said at the time.
The mountain was formed by the collision of the Indian and Eurasian tectonic plates and is thought to grow by around half a metre every century.
However, geologists had suggested that the 2015 Nepalese earthquake could have shifted plates more dramatically, affecting the mountain’s height.
More than 9000 people died in the 7.8 magnitude quake. –