Embracing Uncertainty to Resolve Polar Wander: a Case Study of Cenozoic
North America
Abstract
Our understanding of Earth’s paleogeography relies heavily on
paleomagnetic apparent polar wander paths (APWPs), which represent the
time-dependent position of Earth’s spin axis relative to a given block
of lithosphere. However, conventional approaches to APWP construction
have significant limitations. First, the paleomagnetic record contains
substantial noise that is not integrated into APWPs. Second, parametric
assumptions are adopted to represent spatial and temporal uncertainties
even where the underlying data do not conform to the assumed
distributions. The consequences of these limitations remain largely
unknown. Here, we overcome these challenges with a bottom-up Monte Carlo
uncertainty propagation scheme that operates on site-level paleomagnetic
data. To demonstrate our methodology, we present an extensive
compilation of site-level Cenozoic paleomagnetic data from North
America, which we use to generate a high-resolution APWP. Our results
demonstrate that even in the presence of substantial noise, polar
wandering can be assessed with unprecedented temporal and spatial
resolution.