On pole position: causes of dispersion of the paleomagnetic poles behind apparent polar wander paths

Abstract

Apparent polar wander paths (APWPs) are computed to constrain the past position and motion of tectonic plates and continents relative to the Earth's rotation axis. They provide the reference frame for paleogeography, paleoclimate, and paleoenvironment studies, and serve as the reference against which we compare paleomagnetic data collections obtained from deformed terranes to assess relative latitudinal motions or vertical-axis rotations (e.g.,

On Pole Position: Causes of Dispersion of the Paleomagnetic Poles Behind Apparent Polar Wander Paths

“…We performed these calculations using a set of inhouse‐developed Python codes, for which we made extensive use of the functions and programs from the freely available paleomagnetic software package PmagPy (Tauxe et al., 2016). The Python codes used for this study are publicly available through the online repository on Zenodo (Vaes, 2022; see Data Availability Statement).…”

“…(2018), and can be found both in the original publications as well as in the tables of the Supporting Information S1. The Python codes used for our analyses are publicly available on Zenodo (Vaes, 2022): https://doi.org/10.5281/zenodo.6366399.…”

Influence of Data Filters on the Position and Precision of Paleomagnetic Poles: What Is the Optimal Sampling Strategy?

“…To average between‐site scatter, it is common to collect multiple sites at a locality. The minimum number of sites recommended for determining a paleopole varies between authors (e.g., Meert et al., 2020; van der Voo, 1990), but as shown by (Vaes et al., 2022), paleopoles with larger N tend to plot closer to a best estimate of the time‐averaged paleopole. We perform experiments varying the number of samples per site and the number of sites, with combinations chosen such that the total amount of paleomagnetic samples remains approximately 100.…”

“…Because the accuracy of paleopoles generally decreases with decreasing N, as illustrated by Vaes et al. (2022) for the paleopoles behind the global APWP of Torsvik et al. (2012), applying within‐site scatter filters may systematically decrease paleopole accuracy as well as precision (see also Figure 9).…”

“…Instead of providing such a minimum number, Deenen et al (2011) provided a measure to identify whether the between-site scatter of a data set is straightforwardly explained by PSV alone, using a range of reconstructed values from detailed PSV studies. If datasets indeed represent PSV, the accuracy of the position of a paleopole is expected to increase with increasing number of underlying VGPs, which was recently shown to be true for the paleopoles behind the most recent global APWP (Vaes et al, 2022). Meert et al (2020) suggested eight sites are sufficient to determine a paleopole, provided that each site is constrained by at least three samples.…”