APWP-online.org: a Global Reference Database and Open-Source Tools for Calculating Apparent Polar Wander Paths and Relative Paleomagnetic Displacements

Paleomagnetism provides a quantitative tool for estimating the paleoposition of rock units relative to the Earth’s spin axis and is widely used to determine relative tectonic motions (vertical-axis rotations and paleolatitudinal motions). These motions are commonly quantified as relative paleomagnetic displacements by comparing a study-mean paleomagnetic pole with a reference pole provided by an apparent polar wander path (APWP), even though these poles are calculated by averaging paleomagnetic data from different hierarchical levels. However, this conventional approach was shown to strongly overestimate the resolution at which such displacements can be determined. This problem was recently overcome by comparing paleomagnetic poles computed at the same hierarchical level, whereby the uncertainty of the reference pole is weighted against the number of sites underlying the study-mean pole. To enable the application of this approach, a new global APWP was calculated for the last 320 Ma from (simulated) site-level paleomagnetic data. Applying this comparison method requires a computationally more intensive procedure, however. Here, we therefore present the online, open-source environment (https://apwp-online.org) that provides user-friendly tools to determine relative paleomagnetic displacements and to compute APWPs from site-level paleomagnetic data. In addition, the website hosts the curated paleomagnetic database used to compute the most recent global APWP and includes an interface for adding high-quality paleomagnetic data that may be used for future iterations of the global APWP. We illustrate how the tools can be used through two case studies: the vertical-axis rotation history of the Japanese Islands and the paleolatitudinal motion of the intra-oceanic Olyutorsky arc