The Earth’s magnetic field that protects our planet from the Sun’s deadly solar radiation, has spent the past six months, according to data from a European Space Agency (ESA) satellite array called Swarm.
The main weaknesses in the magnetic field– which extends 370,000 miles, or 600,000 kilometers, over the planet’s surface – have sprung up in the Western Hemisphere, while the field has increased in areas such as the southern Indian Ocean. This data has been compiled using the the magnetometers aboard the swarm satellites which float in tandem.which other.
The scientists conducting the study are uncertain as to why the magnetic field is becoming weaker but one likely reason is that the earth magnetic poles are always ready to flip. Rune Floberghagen, ESA’s Swarm mission manager, agrees and says the data suggests the magnetic north is moving toward Siberia. He says: “Such a flip is not instantaneous, but would take many hundred if not a few thousand years,” Floberghagen told Live Science. “They have happened many times in the past.”
Scientists are already confident that pole shifts occur. Once every few 100,000 years, the magnetic poles flip, so that a compass would point to south, instead of north. While changes in this protective shield are part of the natural cycle, data from Swarm tells us that it’s deteriorating far faster than in the past.
Previously, researchers estimated the magnetic field diminished at a rate of five percent per century. In contrast, this new satellite data forecasts the field will actually weaken at an accelerated rate of five percent per decade. This means that it’s deteriorating five times faster than previously thought. As such, instead of the flip occurring 2,000 years from now, as predicted, the new data suggest it may happen much sooner.
Floberghagen hopes that the more data they receive from Swarm, the more light it will shed on why the field is weakening at a greater and greater pace.
There are no indications that a weakened magnetic field would lead to a doomsday scenario for our planet, in the form of mass extinctions or radiation damage, but researchers do acknowledge that power grids and communication systems would be most at risk.
Earth’s magnetic field acts like a huge invisible bubble that protects it from harmful cosmic radiation. The field exists because Earth has a giant ball of iron at its core, a core that’s then surrounded by an outer layer of molten metal.
This liquid metal, in the outer core, swirls around as the Earth rotates and creates the magnetic field lines that we’re familiar with today.
The movement of the molten metal is why some parts of the field strengthen, while others (in turn) weaken, Florberghagen says. As the temperature in some parts of the core cools, less charged particles are released and weakens the magnetic field across the surface.
“The flow of the liquid outer core almost pulls the magnetic field around with it,” Floberghagen said. “So, a field weakening over the American continent would mean that the flow in the outer core below America is slowing down.”
The Swarm satellites not only read signals from the magnetic field of the earth, but also from its core, mantle, crust and oceans. ESA scientists also hope to use the data to help with earthquake predictions and to make navigation systems (which rely on the magnetic field, such as aircraft instruments) more accurate and pinpoint mineral rich natural resources beneath the Earth’s crust.
These first results were presented at the third Swarm Science Meeting in Denmark on June 19.