Height of Everest

Rope on the way to top

Despite the challenging environment the ambition to measure the height of Mount Everest is strong. According to the chinese historic records the montain was mapped in 1717, by the clerks of Quing dynasty (1644-1912), Between 1847 and 2005 there were 10 attempts to measure the height of the mountain. In 1852 an Indian mathematic and surveyor Radhanath Sikdaroli was the first who stated that Mount Everest id the highest mountain in the world. His measurement methor was trigonometric theodolit calculations in India, 240km from the mountain itself.

The peak was named due to this measurement since Sir George Everest was the head of the survey and mapping project in India. In Indian survey in 1950 the theodolites were used again together with accurate gravity measurements. The resulted height of Everest was 8848m, often used since then. After that the Chinese government survey and cartography department and the head of the department's personnel committee measured the mountain and got a result of 8848.13m.

In 1999 GPS equipment were used when American Everest expedition installed GPS equipment to the top of the mountain and got the height of 8850m. In 2005 China decided to measure the mountain again. After three moths of preparation a group of Chinese climbers reached the top and installed GPS equipment and additional prism equipment. the measurements and calculations were made using theodolites, laser and gravity. To measure the outer sphere there were nine observation points in nearby mountains. According to the leader of the group, the head of Chinese survey department Jiangqi Zhang, this was the biggest, most accurate and assurable measurement ever done in Everest.

The results of the measurement were published 9.10.2005. The rock of the Everest is at the height of 8843m +-0.21m. When the snow and ice layer on top of the rock are added the official height of the Everest is 8848m.