From Directions to Pole Position, Overestimation of Precision and Error Propagation in Palaeomagnetism

Understanding the Earth past history relies on reliable data and an assessment of their uncertainties. Sampling rock specimens from a time interval, palaeomagnetism can provide crucial information about rotational and latitudinal constraints of a crustal block. To produce a palaeomagnetic pole position, there is a hierarchy of averages. However, the common practice is blank out every error from each step as error propagation through the Fisher statistic chain, is not developed. Some geological problems may therefore be created as an artefact of overestimation of precision. This presentation will propose a method based on the Fisher distribution that can be used to propagate all sources of errors into the final pole position estimate for a proper statistical assessment of its uncertainty. The sensitivity on pole position uncertainty using full error propagation on selected cases will be presented.