Earth’s Magnetic Field Made Quick Flip- Flop
2012-10-24 0:00

Byh Charles Q. Choi | LiveScience.com





Earth’s magnetic field reversed extremely rapidly soon after modern humans first arrived in Europe, completely flip-flopping in less than a thousand years, new research suggests.

These findings, detailed Oct. 15 in the journal Earth and Planetary Science Letters,could shed light on how and why magnetic field reversals happen, and how they leave Earth vulnerable to solar and space radiation, the study scientists said.

Earth’s metal core acts like a giant magnet that emanates a magnetic field with two poles, north and south. These two magnetic poles very roughly match where the planet’s geographic north and south poles lie, which mark the axis on which Earth spins.


The Earth’s magnetic field, magnetic poles and geographic poles.

"The Earth’s magnetic field is a highly dynamic feature," said researcher Norbert Nowaczyk, a paleomagnetist at the GFZ German Research Centre for Geosciences. "Its intensity pulsates between values 50 percent higher than today, or 90 to 95 percent lower than today."

In addition, every several hundred thousand years, Earth’s magnetic field reverses — a compass that would have pointed north would instead aim south. These flips are captured by magnetically sensitive minerals in cooling lava that are literally set in stone pointing to where the poles were at that particular moment in Earth’s history.

Failed reversals

Full reversals of the magnetic field usually take millennia to finish, based on those frozen rock records. However, scientists now find that 41,000 years ago, shortly after modern humans first entered Europe, the magnetic poles flipped and flipped again in less than a millennium.

Scientists analyzed data in sediment from the floor of the Black Sea and compared it with other data from the North Atlantic, the Southeast Pacific and around Hawaii. Surprisingly, they found the Earth’s magnetic field took about 200 years to flip, during which time it was just one-twentieth as strong as it is today.

"Former ideas about a field reversal deal with durations of 2,000 to 5,000 years," Nowaczyk told OurAmazingPlanet.

Earth’s magnetic field stayed reversed for only 440 years, during which time it was just one-quarter as strong as it is today. The magnetic poles then flipped back to approximately where they were before over the course of about 270 years. The flip-flop overall is known as the Laschamp event, after the area in France where evidence of it was first discoveredin the 1960s. These new findings reveal how quick this reversal was.




The brevity of this flip overall suggests "it might represent a so-called aborted reversal," Nowaczyk said. "This means the geomagnetic field tried to reverse, but fell back." Such aborted reversals, also known as excursions, may have happened at least a dozen times during the last 780,000 years since the last full reversal, he explained.

Magnetic field shield

Earth’s magnetic field helps protect the planet from energetic particles streaking out from deep space and the sun. During the Laschamp reversal, Earth was significantly more vulnerable to radiation from space, judging by higher levels of radioactive beryllium seen in ice samples from Greenland, Nowaczyk said.

Such radiation poses a particular threat in our modern world, so understanding these reversals is helpful to better understand the threats from space.

"Communication and GPS satellites might be damaged when the cosmic rays are less shielded by the geomagnetic field," Nowaczyk said. "Therefore, it is important to know how dynamic the geomagnetic field is in time and space. We need to know how fast changes in intensity, and thus shielding ability, can happen."

Earth’s magnetic field is generated by the roiling of its outer liquid core. Research suggests that at times this outer core can behave as many magnets instead of one. These magnets can, in principle, cancel each other out, causing the magnetic field overall to weaken or flip.

"We need more data from more sites of the same reversal to get a better understanding of these processes," Nowacyzk said.


Article from: livescience.com





Tune into Red Ice Radio:

Robert Felix - Magnetic Reversal and Evolutionary Leaps

Robert Felix - The Coming Ice Age

Paul A. LaViolette - Earth Under Fire, Galactic Superwaves & Subquantum Kinetics

Susan Joy Rennison - A New Cosmic Age, Space Weather & Cosmic Radiation

Wallace Thornhill - The Electric Universe



Donald E. Scott - The Electric Sky

Randall Carlson - Hour 1 - Cycles of Catastrophe & Cosmic Patterns







Related Articles
Scientist Finds Hidden Portals in Earth’s Magnetic Field
Electrical Engineer Can Feel Magnetic Fields Through Magnets Implanted in His Fingertips
Magnetic polar shift on the sun underway
Moon Oddly Magnetic—Giant Asteroid Crash to Blame?
What If Earth’s Magnetic Poles Flip?
Humans May Have ’Magnetic’ Sixth Sense
Flamingos Drop From Siberian Sky: Locals Mystified (Magnetic Fields Reversing?)
Foxes see Earth’s magnetic field and use it to target prey
Birds use quantum theory to literally ’see’ Earth’s magnetic field as they fly


Latest News from our Front Page

White House Pushes Race War, Then Blames Guns For Flanagan's "Race War"
2015-08-27 5:04
"You want a race war (expletive)?" Asked shooter The Obama administration is blaming guns for the WBDJ-TV shooting, even though the shooter, Vester Flanagan, was influenced by the White House’s race baiting. The White House has been falsely insinuating that racism is the dominant factor behind numerous events over the past several years, even those that didn’t involve race at all, and ...
How Google Destroyed the Internet
2015-08-27 5:12
The internet was created to resolve a simple problem: in communications networks, any central node through which all messages passed was vulnerable to attack or takeover. To counter this, engineers designed a network where any node would pass messages to other nodes, routing around any damage. Then came commerce and the democratization of the internet. Under this model, frightened sheep flock to ...
German government opens borders to all Syrians
2015-08-27 4:00
The German government has flung open Germany’s borders to any and all Syrians, regardless of whether they claim to be asylum seekers. A statement from the German Federal Office for Migration and Refugees said that “Germany will become the member state responsible for processing their claims.” This new diktat means Syrians will no longer have their asylum cases reviewed to see if ...
Left Pushes End of Church Tax Exemptions
2015-08-27 2:51
Emboldened by their latest win in the Supreme Court over same-sex "marriage," the left has been trumpeting the cause tax exemptions for religious institutions at a much faster rate, setting the stage for it to become a national agenda.   Immediately following the Supreme Court decision that declared same-sex marriage legal, Time's Mark Oppenheimer openly declared that churches should be stripped of their ...
Meet America’s First School District to Serve 100% Organic Meals
2015-08-27 2:05
When schools in California’s Sausalito Marin City District return to session this August, they will be the first in the nation to serve their students 100 percent organic meals, sustainably sourced and free of genetically modified organisms (GMOs). More than 500 students at Bayside MLK Jr. Academy in Marin City and Willow Creek Academy in Sausalito will eat fresh, local food ...
More News »