New surprises in the history of the geodynamo - Roger Fu

New surprises in the history of the geodynamo Roger Fu Harvard University The geodynamo is one of the few means by which the Earth's deep interior processes become observable at the surface. The strength and stability of Earth's magnetic field reflect the vigor of convective flows in the core, which in turn depends on how heat is transferred throughout the Earth. I will present paleomagnetic observations of the geodynamo that paint a picture of both surprising stability and punctuated upheaval throughout Earth history. Our work on 3.4 billion-year-old rocks from Australia suggest a remarkably modern-like dynamo with comparable geometry, stability, and intensity. On the other hand, several episodes of weak intensities and directional fluctuations appear to have occurred in the past 600 million years, potentially confounding efforts to reconstruct plate motion during Ediacaran, Devonian, and Jurassic times.