On May 27 a group of Chinese surveyors summited Mount Everest in order to remeasure its height. Theirs will likely be the only ascents the mountain sees this year, along with those recorded by a private Chinese expedition the day after, May 28. The two teams were the only expeditions on the mountain.
The ascent comes after both China and Nepal cancelled the spring 2020 mountaineering season due to COVID-19 concerns. On Everest, climbers live for weeks in tightly-packed camps with little access to emergency medical help, and at high altitudes where even common sickness can be dangerous, the Coronavirus could be especially deadly.
The emptiness is a big change from Everest’s recent overcrowding and lines to reach the summit.
Members of the Ministry of Natural Resources and the national mountaineering team made up the measurement team, the Xinhua News Agency reported.
The remeasuring project began on April 30, but twice bad weather delayed the mission, according to Xinhua. The end of May brought good weather windows allowing the expedition to move up the mountain.
While the surveyors rested for 10 hours at an 8,300-meter camp on May 26, six Sherpa guides climbed to the top, fixed lines, and descended, it said. The surveying group left the camp at around 2:10 am on May 27 and summited at 11:00 am, after which they conducted a series of surveys on the peak: a GNSS, snow depth measurement and gravity survey.
The measurement fieldwork consisted of erecting a survey marker and installing a Global Navigation Satellite System (GNSS) antenna on the peak.
The GNSS receiver now on Everest’s summit can monitor information such as the depth of the snow through satellite measurements. The device communicates with navigation satellite systems globally—the American GPS, European Galileo, Russian Glonass, and Chinese Beidou, but it mainly uses Beidou data.
Since 1949, Chinese surveyors have measured Mount Everest six times and announced its height twice: 8,848.13 meters (29,029.30 feet) in 1975, and 8,844.43 meters ( 29,017.16 feet) in 2005.
There has been an ongoing debate between Nepal and China about whether to include the snowcap in the measurement or not. China believes its 8,844.43-meter measurement—which does not include the snowcap— to be the most accurate, while Nepal believes its measurement of 8,848 meters—snowcap included— is more accurate. The latter height of 8,848 meters is widely cited.
The snowcap itself, however, may have shrunk after the 7.8 magnitude earthquake that struck the Khumbu region in 2015.
The Ministry of Natural Resources said it probably will take two to three months to calculate the exact height of the mountain, the Xinhua News Agency reported.
Calculating the height is a complex process. Scientists will use traditional and modern measurement techniques to perform comprehensive calculations, Xinhua’s Ministry sources said. Following the initial calculations, further theoretical studies and verifications will be undertaken. There are also calculations to eliminate error, such as that caused by temperature, air pressure, and refraction.