The Height of Mount Everest

Elevation: 8,848 m (29,029 ft) Height of Mt. Everest

Longitude: 86 55 31 E 
 

Height of Mount Everest

There are two definitions of the height of Mount Everest.

The first type is snow cap height, which is 8,848.13 meters (29,029 ft) in total. This height is used by climbers and is in favor of studying the changes in ice thickness and global atmospheric.

The second type is the height of the rock (i.e., the geological height), which is 8844.43 meters in total. This height was measured by the China national survey and mapping bureau in 2005. This height is beneficial for the study of the rise and fall of the Himalayas (Mount Everest used to be more than 12, 000 meters 13 million years ago).

The two types of metrical data have both been recognized since 2010.

State Bureau of Surveying and Mapping and Chinese Academy Everest of Sciences announced the altitude of the Mt. Everest as 29,017.16 ft (8, 844.43 m) with accuracy of ±0.69 ft (0.21 m) on Oct. 9, 2005, after several months’ calculation and measurement. They claimed that the data was the most precise and accurate one to date, basing on the highest point of rock not the snow and ice cap on the Mountain. The depth of the snow cap is 3.5 m (11 ft) which measured by Chinese team, and this depth added to the height of the mountain, which finally is in agreement with the net height of 8,848 m (29,029 ft).
 

How to Measure Mount Everest

The height of mount Everest is often referred to as altitude, which is the height difference between the summit and sea level.

Then how to measure the height of Mount Everest?

The measurement of the peak position can use the global positioning system (GPS), its error can be within a centimeter. But due to factors such as the earth is not perfectly spherical, the gap between sea levels around the world can be up to one hundred meters, so the accurate measurement of sea level becomes the main challenge is to measure the height of Mount Everest. Modern geodesy usually solves the problem of sea level change by using geoidal surface.
 

History of Measurement of the Mt. Everest

In 1856, after several years’ calculation, Andrew Waugh announced the height of Mt Everest as 29,002 ft (8,840 m) which later was also known as “Peak XV”. This height was based on Great Trigonometric Survey’s observations. 

In 1955, an Indian survey first announced the elevation of Everest as 8,848 m (29,029 ft). This height was later reaffirmed by a Chinese measurement 8,848.13 m (29,029.30 ft) in 1975. Height of Mt. Everest But the heights announced by the two counties all contained the depth of snow cape.

In 1999, an American Everest Expedition which was directed by Bradford Washburn anchored a GPS unit into the highest rock of the Mt. Everest and calculated out the height as 8,850 m (29,035 ft) with a depth of the snow cape of 1 m (3 ft). The height was not officially recognized by Nepal but is still widely quoted today. In both 1999 and 2005, the height was doubted on its accuracy because of the uncertainty of the geoid.
 

The Changing Height of the Mt. Everest 

According to the plate tectonics theory, the height of the Mt. Everest is adding and the tectonic of the mountain is moving northeastwards. It is suggested that the Mt. Everest is 4 mm (0.16 in) per year (upwards) and about 3-6 mm (0.12--.24 in) northeastwards per year. There are also other ideas that think the northeastwards movement is faster as 27mm (1.1in) and the Mt. Everest is not growing higher but shrinking.
 

Is Mt. Everest the Highest Point on Earth?

Actually, if measured from the sea level, Mt. Everest is the highest point on earth. But several other mountains are sometimes claimed to be the "tallest mountains on earth". 

E.g., Mauna Kea in Hawaii is tallest when measured from its base with height over 10,200 m (33,464.6 ft), but only attains 4,205 m (13,796 ft) above sea level.

By the same measure of base to summit, Denali, in Alaska, also known as Mount McKinley, is taller than Everest as well. But its height above sea level is only 6,190 m (20,308 ft). Denali sits atop a sloping plain with elevations from 300 to 900 m (980 to 2,950 ft), yielding a height above base in the range of 5,300 to 5,900 m (17,400 to 19,400 ft). 

In addition, the summit of Chimborazo in Ecuador is 2,168 m (7,113 ft) farther from earth's centre (6,384.4 km (3,967.1 mi)) than that of Everest (6,382.3 km (3,965.8 mi)), because the earth bulges at the equator. But its height above sea level is only 6,268 m (20,564.3 ft) while Mount Everest's if 8,848 m (29,028.9 ft).