Instability of the Earth's magnetic field over the past 900-700 ka: Insights from a new spherical harmonic field model

Ahmed Nasser Mahgoub1,2, Monika Korte1 and Sanja Panovska1, (1)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Section 2.3 – Geomagnetism, Potsdam, Germany, (2)Geology Department, Assiut University, Assiut, 71516, Egypt, Assiut, Egypt