New study finds Earth’s magnetic field that protects life from energetic particles from the sun and cosmic rays, could flip within a human lifetime. It can take just 100 years to flip. Image © ESA
Earth’s magnetic field has flipped – though not overnight – many times throughout the planet’s history. Now according to scientists intensity of Earth’s magnetic field decreasing 10 times faster than normal.
Its dipole magnetic field, like that of a bar magnet, remains about the same intensity for thousands to millions of years.
For incompletely known reasons it occasionally weakens and, presumably over a few thousand years, reverses direction.
Though a magnetic reversal is a major planet-wide event driven by convection in Earth’s iron core, there are no documented catastrophes associated with past reversals, despite much searching in the geologic and biologic record. Today, however, such a reversal could potentially wreak havoc with our electrical grid, generating currents that might take it down.
UC Berkeley graduate student Courtney Sprain, said:
“It’s amazing how rapidly we see that reversal. The paleomagnetic data are very well done. This is one of the best records we have so far of what happens during a reversal and how quickly these reversals can happen.”
Biaggio Giaccio, Gianluca Sotilli, Courtney Sprain and Sebastien Nomade sitting next to an outcrop in the Sulmona basin of the Apennine Mountains that contains the Matuyama-Brunhes magnetic reversal. A layer of volcanic ash interbedded with the lake sediments can be seen above their heads. Sotilli and Sprain are pointing to the sediment layer in which the magnetic reversal occurred. Credit Paul Renne
source UC Berkeley
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