Investigation of raw variance and variability spectra from non gravimetric geoidal signals

Recent investigations on non-gravimetric geoid undulations at 35 GPS points, within the southem part of the Greek territory, showed the existence of lateral inhomogeneity of the local gravity field, that can be classified into 3 tectonic “provinces”. The possible harmonic degrees, in spherical expansion within which the main causal sources for these inhomogeneities, were found between the range of n=20 and n=70, thus implying a lithospheric origin. In this paper we examine the information content of variance, variability, relative variability spectra of sample point undulations within these 3 tectonic “provinces”. The examination is made in respect to the variation per degree of OSU91A and EGM96 earth models in order to define the depth variation among the main causal sources.