Scientists recalculated the change in magnetic field of Earth with the help of lab simulations and satellites. And they found that the speed of the change is ten times faster than they presumed earlier.
A new study published in ‘Nature Communications’ calculates the changes in the magnetic field from the past hundred thousands of 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” stated by study researcher Chris Davies, University of Leeds, UK.
HOW IS IT GENERATED?
The magnetic field is generated by the convective flow of the molten metal that forms the outer core. The magnetic field is also maintained by that molten outer core.
The electric currents generated by the swirling flow of liquid iron inside the inner core of our planet. The iron resides 2,800 km beneath the planet’s surface. And this molten iron is the reason behind the movements of the magnetic field.
HOW THEY MEASURED THE FIELD?
The constant change of magnetic field was determined with the help of satellites. They act as a means of measuring the current shifts. But the thing is, the magnetic field existed long before the evolution of humans. So how did they find out?
The magnetic fields recorded by lava flow, sediments and man made artifacts were analysed by the scientists. These records led scientists to capture the evolution of the magnetic field.
It is extremely difficult to measure and track the signals from the earth’s core. It concludes that the results are still contradictory.
WHAT THE CURRENT FINDING SAYS?
A research team generated some computer simulations. They combined that data with the reconstruction of time variations in Earth’s magnetic field from the last 1,00,000 years. They concluded that the changes in the direction of the magnetic field are 10 times more larger than the previous reports.
The last report on the change were the fastest scientists ever noted. That was one degree per year. And this recent calculations has defied every last records.
The rock solid example of their findings is the change of geomagnetic field direction 39,000 years ago of 2.5 degrees per year. The shift occurred due to the weak field strength in a confined region near west coast of Central America. And it followed the global Laschamp event- a short reversal of the magnetic field 41,000 years ago.