1. Institute of Geodesy and Geophysics; Vienna University of Technology; Vienna; Austria
2. Department of Geodynamics and Sedimentology; University of Vienna; Vienna; Austria
3. Institute for Geophysics; University of Warsaw; Warsaw; Poland
4. Institute of Geophysics; Polish Academy of Sciences; Warsaw; Poland
5. School of Geology and Geophysics; University of Oklahoma; Norman; Oklahoma; USA
6. Department of Geography and Geology; University of Copenhagen; Copenhagen; Denmark