There are many ways that the height of a mountain can be determined. Altimeters are the easiest approach but theodolites, global positioning systems (GPS) and satellite imagery can also be used.
Determining the exact top or peak of a mountain may be another matter. Mt. Everest has been determined to 8,844.43m [± 0.21m] in height, according to the Chinese State Bureau of Surveying and Mapping. That height is based upon the peak where no snow or ice occurs. Thus it is important to provide an indication about these types of facts. In 1852 the height of the mountain was determined by an Indian mathematician using trigonometry calculations
Today the measurement of moutain heights can more readily be determined through the use of satellite imagery and GPS. Company's such as GeoEye repeatedly capture imagery from different mountains around the world. Improved resolution has enabled measurement of heights in distant, and often inaccessible locations. That information is providing researchers and hydrologic scientists with valuable information about the earth's physical changes and water processes in previously unattainable ways.
Only a few years ago, French surveyors reported in AFP Press that Mont Blanc, the highest peak in the Alps had risen 2.15m in height - that in over only 2 years time. It is widely believed now that mountains are growing quicker at a number of different places around the world. A University of Rochester researcher working on measuring erosion sediments says, "These results really change the paradigm of understanding of how mountain belts grow," says Carmala Garzione. Reported in NASA Earth News, her work uses an entirely different approach to undertsanding mountain history.
One thing is certain, mountain heights are constantly changing. Tectonic movements, climate processes, environmental factors and measurement technologies are all elements involved in these changes and the improved measurement processes.
In addition to these changes are those associated with smaller mountains and hills. While we often assume they are static and do not change rapidly, how do we know unless we measurement them repeatedly?
Source: ASM Magazine
