Affiliation: | 1. National Research Institute of Astronomy and Geophysics NRIAG, Elmarsd St., 11421 Helwan, Cairo, Egypt;2. Department of Mathematics and Geosciences, University of Trieste, Via Weiss, I‐34127 Trieste, Italy;3. International Centre for Theoretical Physics – SAND group, I‐34151 Trieste, Italy;4. Institute of Geophysics, CEA, Beijing, China;5. Geology Department, Faculty of Science, Mansoura University, Mansoura, Egypt |