Is there an Earths Magnetic Field Flip imminent.

[Mike Smith Cosmos]

This reference has just been brought to the attention of the Exeter U3A Geology group. By Marion.:- via Colin Farlow .

 

Marion

Earth's magnetic field, which protects the planet from huge blasts of deadly solar radiation, has been weakening over the past six months, according to data collected by a European Space Agency (ESA) satellite array called Swarm.

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, according to the magnetometers onboard the Swarm satellites -- three separate satellites floating in tandem.

 

The scientists who conducted the study are still unsure why the magnetic field is weakening, but one likely reason is that Earth's magnetic poles are getting ready to flip, said Rune Floberghagen, the ESA's Swarm mission manager. In fact, the data suggest magnetic north is moving toward Siberia.

"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."[50 Amazing Facts About Planet Earth]

Scientists already know that magnetic north shifts. Once every few hundred thousand years the magnetic poles flip so that a compass would point south instead of north. While changes in magnetic field strength are part of this normal flipping cycle, data from Swarm have shown the field is starting to weaken faster than in the past. Previously, researchers estimated the field was weakening about 5 percent per century, but the new data revealed the field is actually weakening at 5 percent per decade, or 10 times faster than thought. As such, rather than the full flip occurring in about 2,000 years, as was predicted, the new data suggest it could happen sooner.

Floberghagen hopes that more data from Swarm will shed light on why the field is weakening faster now.

Still, there is no evidence that a weakened magnetic field would result in a doomsday for Earth. During past polarity flips there were no mass extinctions or evidence of radiation damage. Researchers think power grids and communication systems would be most at risk.

Earth's magnetic field acts like a giant invisible bubble that shields the planet from the dangerous cosmic radiation spewing from the sun in the form of solar winds. The field exists because Earth has a giant ball of iron at its core surrounded by an outer layer of molten metal. Changes in the core's temperature and Earth's rotation boil and swirl the liquid metal around in the outer core, creating magnetic field lines.

The movement of the molten metal is why some areas of the magnetic field strengthen while others weaken, Florberghagen said. When the boiling in one area of the outer core slows down, fewer currents of charged particles are released, and the magnetic field over the surface weakens.

"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 pick up signals coming from the Earth's magnetic field, but also from its core, mantle, crust and oceans. Scientists at the ESA hope to use the data to make navigation systems that rely on the magnetic field, such as aircraft instruments, more accurate, improve earthquake predictions and pinpoint areas below the planet's surface that are rich in natural resources. Scientists think fluctuations in the magnetic field could help identify where continental plates are shifting and help predict earthquakes.

These first results from Swarm were presented at the Third Swarm Science Meeting in Denmark on June 19.

Follow Kelly Dickerson on Twitter. Follow us @livescience, Facebook & Google+. Original article onLive Science.

 

Link :- http://www.livescience.com/46694-magnetic-field-weakens.html

 

 

( As also can be seen on ACME quoted reference ( namely http://www.scienceforums.net/topic/82817-magnetic-field-decrease-of-the-earth/in thread mentioned post # 32 )

 

Mike

Edited July 16, 2014 by Mike Smith Cosmos

[Acme]

Please don't use that large font; it's distracting.

We have a current thread on the topic so there's no need to start another. >> Magnetic field decrease of the Earth!

[Mike Smith Cosmos]

O.K. Thanks ACME

 

 

Hope we are going to survive the flip , when it comes.

 

Mike

Edited July 15, 2014 by Mike Smith Cosmos

[Acme]

O.K. Thanks ACME

snip irrelevant illustration...

Hope we are going to survive the flip , when it comes.

 

Mike

You're welcome. If you will bother to read the other threads I referred you to, you will see that the danger is minimal and over-hyped by no end of publications and individuals.

[swansont]

!

Moderator Note

 

Also, you've been around long enough to know by now that

 

1. You are supposed to provide a link — please do so

 

and

 

2. You are not supposed to quote articles in their entirety.

 

(and also, should one be tempted, that one does not respond to modnotes in the thread)

 

[Ophiolite]

We have very little data on what constitutes normal variation in the magnetic field. We have gross data related full reversals. We have some intriguing data showing large fluctuations during the cooling of a lava flow. (Reference will be dug out if required.) But with handful of centuries of limited data and a couple decades of detailed material I consider it precipitate to predict an imminent flip. It is, however, a great way to scare up more grant money.

 

I know of no prediction that a flip was due in 2,000 years. Someone may have made such a prediction - it is not, to my knowledge, widely accepted.As Acme says the whole thing is overhyped, which is a pity as the whole thing is quite fascinating, without introducing the drama.

[Acme]

We have very little data on what constitutes normal variation in the magnetic field. We have gross data related full reversals. We have some intriguing data showing large fluctuations during the cooling of a lava flow. (Reference will be dug out if required.) But with handful of centuries of limited data and a couple decades of detailed material I consider it precipitate to predict an imminent flip. It is, however, a great way to scare up more grant money.

 

I know of no prediction that a flip was due in 2,000 years. Someone may have made such a prediction - it is not, to my knowledge, widely accepted.As Acme says the whole thing is overhyped, which is a pity as the whole thing is quite fascinating, without introducing the drama.

Something new on the scene Ophi.

 

Earths Geomagnetic Field Intensity is Double the Historical Average

...The intensity of Earths geomagnetic field has been dropping for the past 200 years, at a rate that some scientists suspect may cause the field to bottom out in 2,000 years, temporarily leaving the planet unprotected against damaging charged particles from the sun. This drop in intensity is associated with periodic geomagnetic field reversals, in which the Earths North and South magnetic poles flip polarity, and it could last for several thousand years before returning to a stable, shielding intensity.

...

But according to a new MIT study in the Proceedings of the National Academy of Sciences, the geomagnetic field is not in danger of flipping anytime soon: The researchers calculated Earths average, stable field intensity over the last 5 million years, and found that todays intensity is about twice that of the historical average.

...

Wang and his colleagues, from Rutgers University and France, sought to measure Earths paleomagnetic field using ancient rocks erupted from volcanoes on the Galapagos Islands an ideal site, since the island chain is on the equator. As Earths magnetic field, in its stable configuration, is a dipole, the intensity of the field should be the same at both poles, and half that intensity at the equator.

 

Wang reasoned that knowing the paleomagnetic field intensity at the equator and the poles would therefore give an accurate estimate of the planets average historical intensity.

...