A new study examines the periodicity of geomagnetic field reversals on Earth back to 375 million years ago. The work provides new insight into the patterns of field reversal, and links those patterns to core-mantle processes.

The reversal record of Earth’s geomagnetic field has been integral to theories that describe plate tectonics on Earth. Understanding how planetary magnetic fields are created, and how they develop over time, is also important in understanding the habitable zone around distant stars. Magnetic fields help shield the surface of a planet from charged particles that can cause high levels of radiation and have a detrimental affect on planetary habitability.

The paper, “Does the planetary dynamo go cycling on? Re-examining the evidence for cycles in magnetic reversal rate,” was published in the International Journal of Astrobiology. The work was supported by NASA Astrobiology through the Exobiology & Evolutionary Biology Program.