Mount Everest grows 34 inches as China and Nepal remeasure top of the world

Mt Everest as seen from the way to Kalapatthar in Nepal

The world’s tallest mountain has become a little bit taller after China and Nepal remeasured Mount Everest.

New calculations put the top of the world 86cm (34in) higher than previously recognised, measuring in at 8,848.86m (29,032 feet).

The joint declaration by two national survey teams also settled a long disagreement between neighbouring China and Nepal on Everest’s height. Until this week, Nepal had judged the mountain to be 8,848m, while China considered it four metres lower.

Both sides decided to check the mountain’s height after speculation that a 2015 earthquake in the region had shifted tectonic plates under Everest and global warming may have thinned snow caps.

Nepal had at first planned to conduct the measurement alone, but a joint project was convened under the banner of “eternal friendship” after Chinese President Xi Jinping visited the Himalayan 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 the summit this year after the Covid-19 pandemic closed the mountain to climbers.

The teams used a mixture of GPS data and trigonometric calculations from lower mountains to make their 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, associate researcher at the Chinese academy of surveying and mapping, told the state-run China Daily.

Nepal had previously relied on a 1954 measurement by the Survey of India, but this time conducted its own measuring for the first time. Its surveyors spent two years training for the ascent.

"Before this, we had never done the measurement ourselves," Damodar Dhakal, 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," Mr Dhakal said.

Nepal’s lead surveyor, Khimlal Gautam, 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 is formed by the collision of the Indian and Eurasian tectonic plates and is thought to grow by around half a metre every century. But geologists had suggested that the 2015 Nepalese earthquake could have shifted plates more dramatically under the mountain and affected its height. More than 9,000 people died in the 7.8 magnitude quake, including at least 18 climbers killed when avalanches tore through Everest base camp.

The closure of Everest this year followed concerns the mountain was becoming dangerously overcrowded in 2019. Photographs showed climbers queuing for hours for their chance to stand on the summit and the high altitude congestion was blamed for the deaths of at least two people.