Earth’s magnetic field has a 4,300,000 square mile hole – and it’s growing

A vast region in Earth's magnetic field, known as the South Atlantic Anomaly, has grown significantly and is weakening. This anomaly, a magnetic weak spot roughly 4.3 million square miles in size, has expanded by about two million square miles since 2014, nearly half the size of Europe. It is located over South America and the South Atlantic Ocean, extending toward southwestern Africa. The Earth's magnetic field is generated by swirling iron currents in its liquid outer core, acting as a protective shield against cosmic radiation. However, this field has been weakening globally by about 10% over the last 200 years. The South Atlantic Anomaly is a particular area where this field is much weaker, allowing energetic particles from the Van Allen radiation belts to dip closer to Earth's surface, at altitudes as low as 125 miles. Scientists believe the anomaly's growth and changing shape are due to complex processes within Earth's liquid core and the core-mantle boundary. Specifically, regions where magnetic field lines are reversed, pointing into the core instead of out, have moved and separated, contributing to the anomaly's expansion. Recent data shows this anomaly has a lobe extending toward Africa, while other areas of weakening have also shifted. This growing anomaly poses risks to satellites and spacecraft. Increased exposure to cosmic rays can cause malfunctions, fry electronics, and even lead to blackouts on Earth if severe enough. Satellites passing over the anomaly are often switched off or face a higher chance of damage. While some... download the app to read more