(ORDO NEWS) — The appearance of a mysterious region in the South Atlantic, where the geomagnetic field is rapidly decreasing, has led to speculation that the Earth is moving towards a reversal of magnetic polarity.
However, a new study, which brings together evidence from 9,000 years ago, suggests that the current changes are not unique, and that the polarity reversal may not have happened yet.
The Earth’s magnetic field acts as an invisible shield against the life-threatening environment in space and the solar winds that would otherwise sweep away the atmosphere.
However, the magnetic field is not stable, and at irregular intervals, on average every 200,000 years, a polarity reversal occurs. This means that the north and south magnetic poles are reversed.
Over the past 180 years, the strength of the Earth’s magnetic field has decreased by about 10 percent. At the same time, an area with an unusually weak magnetic field has grown in the South Atlantic off the coast of South America.
This region, where satellites have been knocked out several times by highly charged particles from the Sun, is called the South Atlantic Anomaly. These events have led to speculation that we may be heading towards a reversal of polarity.
“We have mapped the changes in the Earth’s magnetic field over the past 9,000 years, and anomalies like the South Atlantic are likely to be recurring phenomena associated with corresponding changes in the strength of the Earth’s magnetic field,” says Andreas Nilsson, a geologist at Lund University.
The results are based on the analysis of burnt archaeological artifacts, volcanic samples, and sedimentary drill cores, all of which carry information about the Earth’s magnetic field.
Among them are clay pots heated to over 580 degrees Celsius, solidified volcanic lava and sedimentary rocks deposited in lakes or in the sea.
These objects act as time capsules and carry information about the magnetic field in the past. Using sensitive instruments, the researchers were able to measure these magnetizations and recreate the direction and strength of the magnetic field at certain places and times.
By studying how the magnetic field has changed, researchers can learn more about the deep processes in the Earth’s core that generate the field. The new model can also be used to date archaeological and geological records.
“Based on the similarity to the reconstructed anomalies, we predict that the South Atlantic Anomaly is likely to disappear within the next 300 years and that the Earth is not moving towards a polarity reversal,” concludes Andreas Nilsson.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.