Yes we can measure the height of Everest

Yes we can measure the height of Everest

Buddhi Forehead Tika

Buddhi Narayan Shrestha


Government of Nepal Survey Department is going to measure Mount Everest (Sagarmatha) afresh to settle a controversy over height of the world’s tallest peak, especially after some estimates suggested it became a little shorter in the wake of an earthquake two years ago. Before the earthquake, Chinese team had measured the mountain and calculated a height of 8844 meters in 2005, whereas they had measured as 8848 m in 1975. United States calculated Everest’s height as 8850 m in 1999. Italy calculated it as 8846 m in 1993 instead of their prior measurement as 8872 m in 1987.  Originally, height of Everest was first calculated to be 8840 m meters above mean sea level in 1852 by the British India Surveyors team. It was adjusted as 8883 m by Survey of India in 1907. And later India had calculated and established the final height as 8848 m in 1954. Nepal is firm, as it says the traditional height as 8848 m. To overcome all these different measurements, Survey Department has initiated to measure the Everest scientifically and precisely in the years to come.

Everest Measurement Sketch

Methods of measurement

The Survey Department recently organized an international workshop on the ‘Measurement of the Height of Mt. Everest and Global Navigational Satellite System (GNSS) Application.’ Main objective of the workshop was to discuss and finalize on the measurement methodology to be adopted to determine the height of Everest. The workshop was participated and presented papers by surveyors, map makers, photogrammetrists, geodesists, geologists, geophysists, geographers, GIS/GPS experts, equipment manufacturer and Everest summiteer Surveyor from the United States (University of Colorado, National Geographic Society, Trimble Navigation Incorporated), Switzerland (Federal Institute of Technology), Italy (University of Trieste), New Zealand (University of Otago), Japan (University of Tokyo, Shibaura Institute of Technology, Global Positioning Augmentation Service Corporation), Survey of India, China (National Administration of Surveying, Mapping and Geo-information), and various organizations of Nepal.

Height measurement project consists of various activities such as literature review, workshop, height verification, levelling and gravity survey, GPS survey, summit observation, computation, conference and height announcement. During the deliberation, number of issues were raised and discussed whether both the traditional and satellite system should be adopted and rock or snow height to be measured.

It was agreed that precise levelling alignment will be connected to the new adjusted Indian levelling network. It will be extended to four observation stations. The accuracy will be 2 mm/km. The absolute gravity station will be established in the vicinity of the start of new leveling alignment; and observations will be carried out every 2 km along the precise leveling route.

Surface gravity observation in the Everest region, in supplement to airborne gravity, will redefine geoid model with densification of surface gravity observations, to obtain decimeter or better accuracy. Four stations will be continously occupied by the GPS. Trigonometrical survey will be operated and Lines of Sight will be observed from the triangulation stations. Vertical and zenithal angles will be observed from twelve stations. At the same time, the geometry of observation points will be revisited. Reciprocal leveling among summit-observation stations will be done. Deflection of Vertical will be conducted as well.

Meteorological data will be collected from Ev-K2-CNR Lobuche meteorological observations and Department of Hydrology and Meteorology. The department has started the construction of Radiosonde Baloon Station in Kirtipur. The baloon flies every day 18 to 20 kilometres above the ground level within half an hour. During the radiosonde’s ascent, it transmits data on temperature, atmospheric pressure and humidity to the land based receiving station.

Instrumental observations

GPS observation will be carried out in Permanent Bench Marks (every 2km) on the leveling routes. It will be carried out on several stations in the Everest region during observation period. Finally, GPS observation will be made on the summit by the expedition team. GPS, will play a crucial role for the precise and accurate measurement. A signal receiver will be placed at every station, and the team will monitor signals sent between the receiver and satellites. They will then convert the time it takes the signals to arrive into a height measurement. Simultaneously, snow height will be measured through Ground Penetrating Radar (GPR) for snow depth determination. In this way, the height will be calculated using a combination of geodetic data received from three mechanisms: levelling instrument, gravity meter and global positioning system (GPS) to obtain the rock height.

There will have measures of necessary corrections for refraction, deflection-of-vertical, geoid height, atmospheric anomalies and exact thickness of ice on summit. Sufficient attention will be given to minimize the instrumental and human error while measuring, computing and calculating the final height precisely according to the international norms and standards. Errors will be minimized up to the standard precision within permissible error adopted by the concerned scientific work of the world.

Measuring expedition

A mountaineering expedition will be mounted during the summer or autumn climbing season next year of 2018 in a favourable weather condition to measure the height with the set methodology. A team of Sherpas will climb to the top of Everest with measuring equipment. They will obtain sufficient training to handle, operate and record the GPS receivers before the expedition starts. Measurement work meets global standards and that will be internationally accepted to settle the debated height.

There was also a lively discussion that the height of the European Alps mountains and Americas Rocky Mountains and Andes Mountains, Pakistan’s Mount Godwin Austin K-2 (second tallest in the world) and rest of the Himalayan mountains of Nepal have been measured snow height. Then why to bother to find out the snow depth of the Everest summit ? However, it is firmly decided to calculate the rock height.

Taking responsibility

The world is looking to Nepal, as measuring the Everest is a challenging task and it is also an opportunity. They have curiosities like: is Nepal capable to measure and do they have sufficient budget ? The answer may be: Nepal is capable in this field, as it has internationally sound technical manpower with academic education and practical training for many years.

Nepal needs scientific equipments and tools like standard GPS receivers, precise levelling equipment as well as absolute gravimeters, although it has a few instruments and tools of its own. However, to fulfil the extra need, necessary instruments will be managed and procured/hired from international agencies and organizations like International Association of Geodesy and instrument manufacturing factories. Nepal government has spared some budget this year. Adequate amount of budget will be allocated next year, as it has taken as a national priority project.

Associate India and China

In course of measurement, it will be good to involve India and China in the project. It is in a sense that Survey of India found it as the highest peak in the world in 1852 and named Peak-XV. Later, it was named as Mount Everest in 1865. The reason for involving China is that Everest is located between Nepal-China border. However, the peak falls on Nepal side. Everest could be climbed from both Nepal and China side. So it would be appropriate if the Nepali team is joined by Chinese and Indian teams. It would be more relevant and recognizable to associate them during the measurement of the peak and announcement by Nepal.

The Surveyor General of India has sent best wishes to Nepal Survey Department for the success of measurement of the Everest. He has said that measuring the Everest by Nepal is a welcome step. Chinese participants have suggested measuring the peak collaboratively with joint surveys, observations and measurements. They have pledged to extend cooperation.

Nepal’s pride

Everest is Nepal’s treasure and heritage. So it has to measure the mountain and determine the accurate height. Nepal, home to Mount Everest, has never measured the peak on its own. But this is our responsibility as well. It’s a matter of pride and prestige for Nepal to measure the Everest by itself. So Nepal must perform the measurement scientifically; and determine and announce the authentic and latest height that will be acceptable to the scientists and researchers of the world.

Shrestha is the former Director General

of Survey Department and Border Researcher


%d bloggers like this: