Apparent and true polar wander and the geometry of the geomagnetic field over the last 200 Myr

We have constructed new apparent polar wander paths (APWPs) for major plates over the last 200 Myr. Updated kinematic models and selected paleomagnetic data allowed us to construct a master APWP. A persistent quadrupole moment on the order of 3% of the dipole over the last 200 Myr is suggested. Paleomagnetic and hot spot APW are compared, and a new determination of “true polar wander” (TPW) is derived. Under the hypothesis of fixed Atlantic and Indian hot spots, we confirm that TPW is episodic, with periods of (quasi) standstill alternating with periods of faster TPW (in the Cretaceous). The typical duration of these periods is on the order of a few tens of millions of years with wander rates during fast…

• CN
  Centre National de la Recherche Scientifique
• ID
  Institut de Physique du Globe de Paris
• IN
  Institut national des sciences de l'Univers