Deep inside the Earth, liquid iron is flowing and generating the Earth’s magnetic field, which protects our atmosphere and satellites against harmful radiation from the Sun. This field changes over time, and also behaves differently in different parts of the world. The field can even change polarity completely, with the magnetic north and south poles switching places. This is called a reversal and last happened 780,000 years ago.
Now our new study, published in the Proceedings of the National Academy of Sciences, has uncovered how long the field in the South Atlantic has been acting up – and sheds light on whether it is something to worry about.