What does the term "mean sea level" denote in geodesy?

The term "mean sea level" in geodesy specifically refers to the average height of the ocean's surface, which is commonly used as a reference level for various measurements and calculations. This average is determined over a period of time, typically taking into account variations due to tides, atmospheric conditions, and other factors that can influence sea level.

This reference point is essential in geodesy for establishing elevation benchmarks, mapping, and navigation. By using mean sea level as a uniform reference, surveyors and geodesists can ensure more consistent and accurate data when measuring the elevation of landforms, designing infrastructure, and conducting other geodetic work.

The other options do not accurately describe mean sea level. For instance, the highest recorded tide is a specific event rather than an average measure. The calculated depth of oceans pertains to bathymetry and does not relate to a reference elevation above sea level. Lastly, the average level of all freshwater bodies does not reflect mean sea level, as it focuses only on freshwater rather than encompassing the entire ocean surface. Thus, the correct understanding of mean sea level is critical for various applications in geodetic engineering.