51猎奇入口

Synopsis

In the Earth's most recent 100 million years of history, the magnetic field generated by the current in its metallic outer core has undergone nearly 200 spontaneous polarity reversals. These dynamics have been modeled with limited success, restricted significantly by the computational power needed to generate accurate and large-scale magneto-hydrodynamic (MHD) simulations. However, static snapshots of the earth's field have been made possible in Paleomagnetism- a science which assigns a timescale to these reversals by analyzing the spin orientation frozen in minerals formed during different magnetic periods. Characterizing the Earth's field through time has not only extended our understanding of planetary interiors within and beyond our solar system, but has also served as confirmation of continental drift and plate tectonics on Earth. Additionally, magnetic signatures have recently been dated back billions of years, which scientists believe may have played a role for making Earth habitable. In this talk, we will discuss how the Earth's magnetic field has evolved through time, the techniques that have been developed to perform this analysis, and the fascinating implications this has had for studying life on Earth.