Geodesy is the study of the geometry of the earth including its gravity field. The study of geodesy deals generally with the determination of the figure and size of the earth as well as with the study of the earth’s gravity field. Geodynamics on the other hand is concerned with the study of the dynamics of the solid earth including the study and monitoring of plate tectonics, earthquakes, and volcanic eruptions. Geodetic methods are core to the study of geodynamics. Geodesy and geodynamics form the scientific foundation on which various aspects of geospatial engineering are based.