The Earth’s magnetic field, generated 3,000km below our feet in the liquid iron core, is crucially important to life on our planet. It extends out into space, wrapping us in an electromagnetic blanket that shields the atmosphere and satellites from solar radiation.
A long-standing question has been how fast the field can change. Our new study, published in Nature Communications, has uncovered some answers.
Rapid changes of the magnetic field are of great interest because they represent the most extreme behavior of the ocean of molten iron in the liquid core. By tying the observed changes to core processes, we can learn important information about an otherwise inaccessible region of our planet.
Historically, the fastest changes in Earth’s magnetic field have been associated with reversals, which occur at irregular intervals a few times every million years. But we discovered field changes that are much faster and more recent than any of the data associated with actual reversals.
Nowadays satellites help monitor changes in the field in both space and time,…