Daji Landis, Deutsches GeoForschungsZentrum GFZ, Potsdam, Germany, Irina S Zhelavskaya, Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany, Yuri Shprits, GFZ German Research Centre for Geosciences, Potsdam, Germany and Nikita Aseev, University of California Los Angeles, Los Angeles, CA, United States