Scientists are watching a growing “dent” in the Earth’s magnetic field across a swath of the Atlantic Ocean that stretches from South Africa to the west in Brazil.
In this zone, known as the South Atlantic Anomaly, the magnetic field – the invisible shield that protects the planet from radiation and charged particles from the sun – is weaker than normal. Although not thought to be dangerous to humans, experts say the weak spot could cause glitches as permanent damage to Earth-orbiting satellites that are exposed to energetic particles as they fly through the region.
“Those particles can be destroyed by satellite instrumentation, so it’s good to follow the South Atlantic Anomaly, and especially the changing form, so we can take preventative action,” said Terence Sabaka, a geophysicist at NASA’s Goddard Space Flight Center. Greenbelt, Maryland, sei.
Scientists have known about the weak spot in the Earth’s magnetic field for several decades, but new research suggests that the South Atlantic anomaly is growing, spreading further west toward the Pacific Ocean, and is further weakening.
“Satellite measurements, such as theoretical modeling, predict that the area will be larger in the next five years or more, and the strength of the magnetic field in that area will be even lower,” said Weijia Kuang, a geophysicist and mathematician at NASA Goddard’s Geodesy and Geophysics Laboratory, sei.
Kuang admitted that the weak spot also seems to split in two, although it is not yet known what specifically drives that process.
The Earth’s magnetic field is generated by the constant movement of liquid metal in the iron – rich outer core of the planet, roughly 1,800 miles below the surface. When these molts are cut off, they produce electric currents that effectively convert the earth’s magnetic field and the planet into a giant bar magnet.
But the constant clutter in the outer core means that the magnetic field tilts, and that is why the magnetic poles are not perfectly aligned with the terrestrial geographic north and south poles. This dynamic deep within the planet also creates fluctuations and instability in the magnetic field.
In general, the magnetic field is strongest at the wrist and weaker at the equator, but more research is needed to understand the exact cause of the South Atlantic Anomaly.
“It’s like a weakness on top of a weakness,” Sabaka said, adding that although other spots exist where the magnetic field is less intense, the one across the Atlantic is by far the largest and most important.
Sabaka and Kuang have mapped out the South Atlantic Anomaly, but more data will help them refine their models and build more accurate forecasts on how the weak spot could change over time.
Kuang said that these insights will not only help protect satellites and other spacecraft in orbit around the Earth, but they will also give scientists a better understanding of processes that are deep in the planet for hundreds of thousands or millions of years. have worked out.
“This provides a very, very important window for us to examine the interior properties of the Earth,” he said, “and to understand the Earth as a whole about its evolution.”
