New Delhi | Jagran News Desk: Scientists in the United Kingdom have revealed that the changes in the Earth’s magnetic field may take place 10 times faster than it was thought previously. The revelation was made after the scientists at the University of Leeds in the UK used simulations for the process.
Giving new insight into the swirling flow of iron 2,800 km below the Earth’s surface, a study published in the journal Nature Communications also highlighted how the flow of iron influenced the magnetic field movement during the past hundred thousand years.
"We have very incomplete knowledge of our magnetic field prior to 400 years ago. Since these rapid changes represent some of the more extreme behaviour of the liquid core, they could give important information about the behaviour of Earth's deep interior," said study researcher Chris Davies from the University of Leeds in the UK.
According to the researchers, our magnetic field is generated and maintained by a convective flow of molten metal that forms the Earth's outer core. Thus, the magnetic field is constantly changing. Satellites now provide new means to measure and track its current shifts but the field existed long before the invention of human-made recording devices.
Scientists have now analysed the magnetic fields recorded by sediments, lava flow, and human-made artefacts to capture the evolution of magnetic fields. Accurately tracking the signal from Earth's core field is extremely challenging and so the rates of field change estimated by these types of analysis are still debated.
During the current research, the UK scientists combined computer simulations of the process of magnetic field generation, with reconstruction of time variations in Earth's magnetic field spanning the last 100,000 years.
The findings revealed that the changes in the direction of Earth's magnetic field occurred 10 times larger than the fastest currently reported variations of up to one degree per year. They demonstrate that these rapid changes are associated with local weakening of the magnetic field.
This means these changes have generally occurred around times when the field has reversed polarity or during geomagnetic excursions when the dipole axis moves far from the locations of the North and South geographic poles.
This shift was associated with locally weak field strength, in a confined spatial region just off the west coast of Central America, and followed the global Laschamp excursion - a short reversal of the Earth's magnetic field roughly 41,000 years ago.
(With IANS Inputs)
Posted By: Talib Khan
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