Earth Tipped on Its Side During the Age of Dinosaurs–and Not Just Once
2 days ago
- Earth is not perfectly spherical but an oblate spheroid, causing true polar wander where geographic poles drift relative to the spin axis.
- A new study using ancient sea-level records found that rapid true polar wander episodes caused significant sea level changes during the Jurassic and Cretaceous periods.
- Four intervals of rapid true polar wander were identified: mid-Cretaceous, Late Jurassic to Early Cretaceous, Early Jurassic, and Oligocene to Miocene.
- The findings challenge the previous view that true polar wander was negligible or slow, and highlight its underappreciated impact on global environment and biological dynamics.