Inversion of airborne gravity data to infer bathymetry in the Mediterranean around Italy
21/09/2016 | 09:00 | Session 4: On the ground and airborne gravimetry
Author(s): Theresa Schaller, Franz Barthelmes and Mirko Scheinert
Theresa Schaller, Franz Barthelmes and Mirko Scheinert
The inversion of gravity data is a widely used tool in geodesy and geophysics to infer the depth to an unknown interface. It can be used to obtain bathymetry, subglacial topography or the depth to the Mohorovičić discontinuity in areas, where these interfaces can not be observed directly. We analysed gravity data obtained from the GEOHALO mission carried out in June 2012 using the German research aircraft HALO. This mission was flown in the area of Italy and adjacent Aegean, Ionian and Tyrrhenian seas. These gravity data were used to infer bathymetry in the study area utilizing a Parker- Oldenburg inversion scheme. To validate our resulting bathymetry we could make use of available bathymetry datasets inferred from in situ measurements. Thus, this comparison helps to improve the method and to establish a feasible inversion procedure. In the Adriatic Sea the correlation between gravity and bathymetry is weak, due to thick sedimentary cover, which hinders the inversion. The observed gravity in the Tyrrhenian Sea is influenced mainly by the gravity effect of the African plate subducting underneath Eurasia. However, the results show that the procedure is able to derive bathymetric depths with sufficient accuracy. For this, it is important to find feasible parameters such as filter wavelength, density contrast and approximate depth to the interface. Furthermore, an outlook will be given to the application of this method to obtain subglacial topography in Antarctica.