We all know that Mount Everest is the highest mountain in the world but over the years it has been measured many times using the latest available technology at the time giving slightly different results. In 1856 Andrew Waugh declared Peak XV as it was called in those days to be 29,002 feet high based on his computations and observations through the Great Trigonometric Survey.
The height of Mount Everest is 8,848 meters or 29,029 feet, which has been recognized officially in both China and Nepal. After many years of calculation and measurements, on the 9th October 2005 the State Bureau of Surveying and Chinese Academy of Sciences made an official announcement that the height of Mount Everest was actually 29,017.16 feet or 8,844.43 meters with accuracy of 0.69 feet (0.21 meters).
It was claimed to be the most precise measurement ever taken. This height is based on the top of the rock on the summit of Mount Everest and does not include the ice and snow which covers it. They also measured the ice and snow depth of 11 feet which increases the net height to 8,848 meters. The ice and snow thickness can vary over time and it is not possible to find out the precise height of snow cap.
The elevation of Mount Everest as 29,029 feet was found out in 1955, by an Indian survey with the use of theodolites. It was then reassured by a Chinese measurement during 1975 which also stated that the height was 8,848.13 meters. In both measurements, the snow cap was considered and they did not measure the rock head.
An American Expedition was conducted during the month of May in 1999, headed by Bradford Washington, who grounded a GPS unit to the top most bed rock. The elevation was found to be 29, 035 feet (8, 850 meters) and the snow cap elevation was found to be 3 feet (1 meter) higher with the help of GPS. Though it was recognized by Nepal officially, it is quoted widely. Geoid casts of uncertainty doubt upon precision of the results claimed by surveys conducted during 2005 and 1999.
It is considered that tectonic plates of the regions are incrementing the height of region as they move the summit in north east direction. There are suggestions the rate of increase is up to 4 millimeters per year in upward direction and 3 to 6 millimeters in a northeast direction. There is another theory suggesting a lateral movement of some 27 millimeters a year.
Today the height of 29,029ft (8,848m) is officially recognized as the correct elevation for the highest mountain in the world, Mount Everest by Nepal, China and many from around the world.