The Earth’s magnetic field is a crucial shield that protects against dangerous radiation and geomagnetic activity, guarding satellite communication and power grids. Over time, the movement of magnetic poles points to a potential field reversal. However, these events unfold gradually, stretching across millennia.
Magnetic fields, such as the one surrounding Earth, result from the movement of electric charges through conductors like metal. Underneath Earth’s surface, there is a liquid iron core responsible for generating its magnetic field. As a result, Earth’s magnetosphere protects against high-energy, cosmic-ray radiation, while also interacting with solar wind to create space weather. Notably, the Sun can cause geomagnetic storms during large emissions called coronal mass ejections.
Scientists have tracked the Earth’s magnetic field’s changes and found that the north magnetic pole has moved roughly 600 miles since measurements began in 1831, indicating a potential field reversal. The reversal typically occurs every 100,000 to 1,000 years. During these events, the orientation of Earth’s magnetosphere may shift, increasing exposure to cosmic radiation. According to studies of volcanic rocks in the ocean, field reversals typically happen over a few thousand years.
While it’s unclear when the next field reversal will happen, tracking the Earth’s magnetic north helps maintain a clear picture of the field’s movement. Ofer Cohen of UMass Lowell shared these insights, demonstrating the complex nature of Earth’s magnetic field and its lasting impacts.
