1. School of Physics, Univesiti Sains Malaysia, Pulau Pinang, Malaysia, 11800
2. Geology Department, Faculty of Science, Helwan University, Helwan, Cairo, Egypt, 11795
3. National Research Institute of Astronomy and Geophysics, Helwan, Cairo, Egypt, 11421
4. School of Earth and Space Sciences, University of Science and Technology of China, Hefei, People's Republic of China