Fig. 2. Power-law relationship, shown on linear and log axes, enabling estimation of first-order geomagnetic field morphology from palaeosecular variation analysis.

Red points are observation-based models (Supplementary Table 1) testing the relationship which is based entirely on dynamo simulation outputs (blue hollow points; Supplementary Data 1). Shaded area is 95% prediction bounds calculated from a linear regression performed in log-space.