We have used a comprehensive data compilation and recently refined modelling strategies to produce CALS10k.1b, the first time-varying spherical harmonic geomagnetic field model spanning 10 ky. The model is an average obtained from bootstrap sampling to take account of uncertainties in magnetic components and ages in the data (and hence has version number 1b instead of 1). This model shows less spatial and temporal resolution than earlier versions for 0 - 3 ka, and particularly aims to provide a robust representation of the large-scale field at the core-mantle boundary (CMB).


  • Korte, M., C. Constable, F. Donadini and R. Holme (2011): Reconstructing the Holocene Geomagnetic Field. Earth Planet Sci. Lett., 312, 497-505

Radial field component (Br) at the core-mantle boundary


CALS10k_1b.zipZIP750kBDec. 2011Model file CALS10k.1b with Fortran source code to obtain time series of field predictions at the Earth's surface with uncertainty estimates (CALS10kfield.f) and to obtain the GAUSS coefficients for one point in time (CALS10kcoefs.f). ZIP33MBDec. 2011Animations of radial field component (Br) at the core-mantle boundary and of field intensity at the Earth's surface. ZIP80kBDec. 2011Plain text file with dipole moment estimate from CALS10k.1b.


Profile photo of  Dr. Monika Korte

Dr. Monika Korte

Behlertstra├če 3a
Building K 3, room 116
14467 Potsdam
tel. +49 331 288-1268