A set of free-air gravity anomalies for Austria and neighbour countries represents the gravitational field data for the current investigation. The depths of the Mohorovičič discontinuity (Moho depths) derived by seismic observations are also available. The computation of the terrain reduction is carried out using the pre-estimated seismic Moho depths. The TC-program (originally written by Forsberg, 1984) has been modified to compute the effect of the compensating masses on the disturbing potential (and hence to other gravitational quantities) using the Digital Moho Models. Both fine (11.25″ x 18.75″) and coarse (90″ x 150″) Digital Height Models are available for this investigation. The gravimetric geoid for Austria has been computed using the seismic Moho depths, representing the compensating masses, by applying Stokes’ integral in the frequency domain using 1D-FFT technique. For the sake of comparison, another gravimetric geoid for Austria has been computed using the Airy-Heiskanen isostatic model, for generating the compensating masses. Both geoids are scaled (fitted) to the geoid derived from GPS and levelling. A broad comparison between both geoids is carried out. Both geoids have nearly the same accuracy. Using seismic Moho depths in the geoid computation gives fitted geoid with less difference range (compared to the GPS-derived geoid) than the geoid computed using Airy-Heiskanen isostatic hypothesis.
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- Gravimetric Geoid Computation for Austria Using Seismic Moho Data
Hussein A. Abd-Elmotaal
- Springer Berlin Heidelberg
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