All articles tagged with #true polar wander
New analysis of ancient sea-level data indicates that Earth's geographic poles shifted rapidly during the Jurassic and Cretaceous periods, moving up to 0.6 degrees per million years. This 'true polar wander' occurred as the planet's crust and mantle reoriented relative to its spin axis to balance mass distribution, potentially altering global climate patterns and habitats for dinosaurs and early primates.
A new study in Science identifies four intervals of rapid true polar wander in the last 320 million years, challenging the view that Earth's solid exterior has only shifted slowly. Led by Mathew Domeier at the University of Oslo, the research uses ancient sea-level changes rather than magnetic data to detect these events. The strongest signals occurred during the Jurassic and Cretaceous periods, suggesting the planet’s crust and mantle reoriented rapidly relative to its spin axis, potentially altering global climate and habitats.
Researchers reconstructed the Antarctic geoid low over ~70 million years, showing a persistent gravity valley shaped by deep mantle flow and evolving upper-mantle buoyancy. A major change in amplitude and position occurred between 50 and 30 million years ago, linked to long‑term subduction and upwelling, with a possible connection to true polar wander and Antarctica’s ice-sheet history. The study cautions that while deep-Earth dynamics can reshape the gravity field, translating this into climate or ice-sheet impacts requires further work.