A huge hole in Earth’s magnetic field continues to expand, according to the latest information obtained by three satellites monitoring the planet. This is called The South Atlantic Anomaly (SAA) and stretches along the area between Africa and South America. The data shows that since 2014, the anomaly has extended by about half the area of continental Europe, and the strength of the magnetic field in the area continues to decrease.
The measurements suggest that Earth’s molten iron liquid outer core, which generates the magnetic field, is neither stable nor calm. It is turbulent and complex, and its behavior can change the external magnetic field in just a few years.
In this article, you’ll learn how Earth’s magnetic field works, why it’s essential to life and technology, how it affects satellites and humans at high altitude, and what important discoveries the Swarm mission made about the complexity The South Atlantic Anomaly and the mysteries of the depths of the planet.
Earth’s Magnetic Field: Protection and Impact on Life and Technology
The Earth’s magnetic field is a vast network of invisible lines, generated by the dynamic movement of the planet’s core. The outer core consists of a hot, conductive, constantly moving fluid that converts the energy of motion into magnetic energy. This field extends into space, protecting the planet’s atmosphere like an invisible shield.
The atmosphere contains important gases such as oxygen, nitrogen and hydrogen, which are vital for life and for maintaining the climate. Without this magnetic field, some of these light gases, such as hydrogen and helium, could gradually escape into space. The magnetic field also protects the atmosphere from solar and cosmic radiation that could erode or alter it.
The South Atlantic Anomaly–the deep mystery that weakens Earth’s magnetic shield/NASA
In short, due to the magnetic field:
- Oxygen and nitrogen remain sufficient for humans, animals and plants to live;
- The climate remains stable;
- The atmosphere is protected from dangerous radiation.
Without this “shield”life and conditions on Earth would be much more exposed and fragile.
Over billions of years, the magnetic field has varied in strength and sometimes reversed completely. These changes are not directly dangerous to life on the surface, but they can affect technology and increase the risk of people and equipment being exposed to radiation.
Effects of weakening magnetic field on satellites and humans
Some navigation systems depend on the Earth’s magnetic field, and satellites or electronic equipment in space can be affected by charged particles moving around the planet. When the magnetic field is weaker, this equipment becomes more vulnerable to the accumulation of dangerous electrical charges.
The magnetic field also protects people traveling at high altitudes or in space. It deflects solar and cosmic radiation, reducing the amount of radiation reaching the human body. In areas where the magnetic field is weaker, radiation exposure increases, which can affect astronauts or passengers on high-altitude aircraft.
By studying how the magnetic field changes, scientists can better understand what’s happening deep within the Earth and build models to help protect technology and human health.
Swarm reveals the complexity of the South Atlantic Anomaly
The South Atlantic Anomalyor SAAhas been observed since the 1960s. However, detailed and constant studies of this region only began in 2013, with the launch of the European Space Agency’s (ESA) Swarm mission. The latest research on this topic was published in Physics of the Earth and Planetary Interiors.
This mission uses three satellites working together to map the Earth’s magnetic field.
The results obtained by Swarm represent the longest continuous monitoring of the magnetic field to date and have shown that the SAA is more complex than previously thought.
“The South Atlantic Anomaly is not a uniform block. It behaves differently in the area of Africa compared to the region near South America. Something special happens in this area that makes the weakening of the magnetic field stronger”explains geophysicist Chris Finlay from the Technical University of Denmark.
Magnetic field reversal beneath the South Atlantic Anomaly
Scientists don’t know exactly what causes it The South Atlantic Anomalybut they noticed that below this region, the Earth’s magnetic field behaves differently than expected. In general, the planet’s magnetic field is roughly dipolar: field lines emerge from the south pole and collapse into the north pole. This is a simplified explanation, but it helps to understand how the magnetic field is expected to work.
At SAA, however, some of the magnetic flux inside the Earth is reversed. “Typically, we would expect to see field lines moving out of the core in the Southern Hemisphere. Instead, beneath the South Atlantic Anomaly we see unexpected areas where the magnetic field returns to the core. The Swarm data shows that one of these areas is moving westward over Africa, contributing to the weakening of the magnetic field in this region.” explains Chris Finlay.
The deep-Earth hot spot and the effect on the magnetic field and the Swarm satellites
This reversal of magnetic flux could be linked to a large and mysterious region of extremely hot material located outside the Earth’s core, known as The Great Low Shear Rate African Province (LLSVP), located in the SAA area.
The hot spot could disrupt the movement of the fluid in the Earth’s core, which influences the behavior of the magnetic field above it. Scientists consider this phenomenon to be normal for the planet, but only recently could it be studied in detail thanks to modern instruments.
Other changes observed by the Swarm mission satellites include a slight weakening of the magnetic field over Canada and a slight strengthening over Siberia, phenomena linked to continuously evolving magnetic structures beneath North America.
“It’s fascinating to be able to see the full picture of our dynamic Earth. The satellites are operational and provide excellent data, so we hope to continue this monitoring beyond 2030, when solar minimum will allow us to study the planet with unprecedented precision.”says Anja Stromme, Swarm mission manager at ESA.
What changes in the magnetic field mean for the future of the planet and technology
Continuous monitoring a The South Atlantic Anomaly and the Earth’s magnetic field provide scientists with essential information about the dynamics of the planet’s depths and how these changes may influence life and technology. Weakening magnetic fields or magnetic flux reversals do not pose an immediate danger to people, experts say, but they can affect satellites, navigation systems and sensitive electronic equipment.
At the same time, the magnetic field remains the main one “shield” of the Earth against solar and cosmic radiation, protecting the atmosphere and helping to maintain a stable climate. Studies by the Swarm mission and other similar programs enable the building of more accurate predictive models, helping to anticipate risks and develop strategies to protect technology and human health.
As research progresses, scientists will better understand the magnetic field’s complexity, evolution The South Atlantic Anomaly and their impact on the planet. In this way, we can be better prepared for the future and continue to benefit from the Earth’s natural protection against radiation and disturbance, ensuring life, technology and safety for future generations.
