The Earth’s magnetic field – our protection from space radiation – is weakening at an alarming rate!
But what is more concerning is that we don’t understand why! Are Earth’s poles about to flip?
[quote_box_center] Earth’s magnetic field, which protects the planet from huge blasts of deadly solar radiation, has been weakening over the past six months.
The biggest weak spots in the magnetic field — which extends 370,000 miles (600,000 kilometers) above the planet’s surface — have sprung up over the Western Hemisphere, while the field has strengthened over areas like the southern Indian Ocean. [/quote_box_center]
Evidence of weakening of the magnetic field, and it’s geographically inconsistent nature, has been tracked for decades, but the November 2013 launch of the European Space Agency’s three satellite Swarm constellation has allowed unprecedented precision in measuring these changes. These new results were presented at the Third Swarm Science Meeting and demonstrate the excellent performance of Swarm satellites.
Effects of a weaker magnetic field
A weaker magnetic field would expose the planet to increased radiation, both from distant supernovae and from the solar events, although there is no evidence that the doomsday scenario of a planet temporarily without any magnetic field at all has ever occurred.
A polarity flip, or drastic weakening would not be lethal, as demonstrated by the fact that past changes have not been associated with mass extinctions, but could expose powerlines and communication systems to much greater danger.
On the positive side, auroras should become more spectacular and widespread.
What drives these changes?
These magnetic changes are driven by a complex set of sources, from the core, mantle and crust of the Earth and influences in space.
The largest influence is thought to be the convection currents in the molten iron of the core causing expansion at some points and contraction at others. Thee convection currents may sometimes lead to domains where the magnetic field runs in the opposite direction to the main field, canceling part of it out.