How high is Mount Everest actually? Nepal and China did not agree on this question for a long time - because they each used their own reference system for measuring altitude. An agreement was reached at the end of 2020. The reason: the two countries now used an international height reference system as the basis for their measurements. The reference value is no longer a specific sea level ("above sea level"), but a so-called global equipotential surface. This refers to the Earth's gravitational field: all points on the equipotential surface have the same gravitational potential. In order to measure the height of locations on the earth, one simply determines the respective deviation from this gravitational potential. The current Geowerkstatt project shows that optical atomic clocks are particularly suitable for these measurements.
Read the Geowerkstatt project of the month here:
GeoWerkstatt project July 2025
Info GeoWerkstatt - Insights into research
GeoWerkstatt is published monthly here on this website. Scientists take it in turns to report on their current research projects in the field of geodesy and geoinformatics. The Geodetic Institute (GIH), the Institute of Geodesy (IfE), the Institute of Cartography and Geoinformatics (IKG) and the Institute of Photogrammetry and GeoInformation (IPI) are involved.
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