Reacción a "Geomagnetic anomalies in the Southern Hemisphere that pose a threat to satellites are a recurring phenomenon, according to research"

The Earth’s magnetic field can be understood as a protective shield that safeguards us from cosmic radiation and charged particles that bombard our planet via the solar wind. Without it, life as we know it would not exist. However, this field is neither static nor permanent; in fact, it is constantly changing over time. The direct information we have about the geomagnetic field is relatively recent and dates back to the development of the first instruments capable of measuring it accurately, namely magnetometers. To understand what the magnetic field was like before instrumental measurements existed, scientists must rely on indirect records preserved in geological and archaeological materials. The study of these records, which form the basis of palaeomagnetism and archaeomagnetism, makes it possible to reconstruct the evolution of the geomagnetic field over thousands and even millions of years. Thanks to this research, we now know that the Earth’s magnetic field not only varies in strength and position, but has also undergone numerous polarity reversals throughout Earth’s history.

The so-called South Atlantic Anomaly (SAA) is a “dent” in the Earth’s magnetic field over South America and the South Atlantic Ocean, where the decline in intensity of the Earth’s dipole field over the past 160 years is most pronounced. In order to better understand this phenomenon, Miriam Gómez-Paccard and F. Javier Pavón Carrasco, both with extensive professional experience and a strong reputation in the field, have led a palaeomagnetic study of more than 250 fragments of well-dated fired clay archaeological materials. Their results support the idea that the geomagnetic field follows large-scale recurrent patterns and depends on geodynamic processes operating at different scales. In this system, the Earth’s mantle and core interact and together influence the slow changes in the magnetic field over centuries and millennia.

The results are relevant not only for advancing our understanding of the geomagnetic field and, consequently, Earth’s history, but also due to the importance of the SAA for space safety, as satellites passing over this region are exposed to higher doses of incoming radiation because of the weaker geomagnetic intensity. This can cause failures or damage to critical hardware components and even disruptions in operation.

Improving our understanding of the geomagnetic field is therefore relevant not only for fundamental science, but also for technology, space exploration, and the protection of critical infrastructure.