Is Unusual Low Magnetic Field in South Africa Linked to Future Magnetic Reversal? — Audio Interview

“We don’t know that the changes we’re seeing today are the start of a magnetic reversal, but what we do know is that the changes are unusual.”
– John Tarduno, Ph.D., Prof. and Chair, Earth and Environmental Sciences Dept., University of Rochester, Rochester, New York

March 31, 2018 Rochester, New York – Over the past 400 years, the Earth’s magnetic field has steadily weakened by 15%. In only the past 160 years, the magnetic field weakened by 10%. The magnetic fields give us our North and South poles, make it possible for humans to travel with compasses and birds and lots of marine life to navigate. Earth’s strong magnetic fields also protect all surface life from the bombardment of harmful radiation from our Sun and outer space.

On the left, the Earth’s magnetic field we’re used to. On the right, a model of what the magnetic field might be like during a reversal. Illustrations by Gary Glazmaier/NASA.
On the left, the Earth’s magnetic field we’re used to. On the right, a model of what the magnetic field might be like during a reversal. Illustrations by Gary Glazmaier/NASA.
Earth’s geomagnetic field surrounds and protects our planet from harmful space radiation. Illustration by NASA Goddard Space Flight Center.
Earth’s geomagnetic field surrounds and protects our planet from harmful space radiation. Illustration by NASA Goddard Space Flight Center.

Oddly, the weakening magnetic field has been concentrating in one big Southern Hemisphere region that stretches from Chile to South Africa and is called the “South Atlantic Anomaly.”  It’s truly odd because it’s the Southern Hemisphere, but it’s called a “Reverse Flux Patch” because it has the magnetic orientation of the North magnetic pole, but is in the Southern Hemisphere. The magnetic field strength is so weak there that it’s a hazard for satellites that orbit above the region where the magnetic field no longer protects them from radiation which interferes with satellite electronics. Scientists even joke that the anomaly now is equivalent to a “Bermuda triangle for satellites.”

South Atlantic Anomaly is called a “reverse flux patch” because it has the magnetic orientation of the North magnetic pole, but it is in the Southern Hemisphere. Scientists joke that the anomaly now is equivalent to a “Bermuda triangle for satellites.”
South Atlantic Anomaly is called a “reverse flux patch” because it has the magnetic orientation of the North magnetic pole, but it is in the Southern Hemisphere. Scientists joke that the anomaly now is equivalent to a “Bermuda triangle for satellites.”

The South Atlantic Anomaly (SAA) is an area where the Earth’s inner Van Allen radiation belt comes closest to the Earth’s surface, dipping down to an altitude of 200 kilometers (120 mi). This leads to an increased flux of energetic particles in this region and exposes orbiting satellites to higher-than-usual levels of radiation.

This has caused computers to crash on the International Space Station during fly overs of the South Atlantic Anomaly. In 2016, Japan’s Hitomi X-ray observation satellite was supposed to study black holes and supernovas. But when it passed through the weak magnetic anomaly, the satellite went spinning out of control.


See Websites below.

Now comes a new study published in the science journal Geophysical Research Letters. The lead investigator was Professor John Tarduno, Ph.D., Professor and Chair of the Earth and Environmental Sciences Department at the University of Rochester in Rochester, New York. He and his team worked with archaeologists in the Limpopo River Valley between Zimbabwe, South Africa and Botswana. There some of the world’s most ancient farmers had a ritual of fire where the Bantu people now live. The ancient farmers would burn their village completely down if there was a drought or big problem. The idea was that burning down their village would enable everyone to start anew – a kind of ritualistic cleansing in the fire.

Prof. John Tarduno, Ph.D., lead an archaeological investigation of thousand-year-old Iron age village sites on the Limpopo River Valley that today borders Zimbabwe, Botswana and South Africa. Ancient burned clay pottery and huts contain tiny magnetic minerals that show what the magnetic field orientation in South Africa was back then. Prof. Tarduno concludes the SAA anomaly is a pattern that has persisted for over 1,000 years. That's why scientists wonder if it's a precursor to a magnetic reversal, otherwise known as a pole flip, that has not happened for 780,000 years. Image © 2018 by John Tarduno, Ph.D., Univ. of Rochester, N.Y.
Prof. John Tarduno, Ph.D., lead an archaeological investigation of thousand-year-old Iron age village sites on the Limpopo River Valley that today borders Zimbabwe, Botswana and South Africa. Ancient burned clay pottery and huts contain tiny magnetic minerals that show what the magnetic field orientation in South Africa was back then. Prof. Tarduno concludes the SAA anomaly is a pattern that has persisted for over 1,000 years. That’s why scientists wonder if it’s a precursor to a magnetic reversal, otherwise known as a pole flip, that has not happened for 780,000 years. Image © 2018 by John Tarduno, Ph.D., Univ. of Rochester, N.Y.

Now Professor Tarduno has discovered that when the ancient clay pots and huts were burned, the intense heat caused magnetic minerals in the burned clay residue — sort of like tiny compass needles — to align with the Earth’s magnetic field leaving a detailed record of what the magnetic field was in South Africa as far back as 1550 B. C.  The investigation shows there is something unusual about the core-mantel boundary under South Africa that could have an important impact on the whole Earth global magnetic field. And Prof. Tarduno thinks that impact now is an unusually low magnetic field that keeps weakening. Does it mean Earth is finally headed for a magnetic pole reversal, also known as a pole flip, when the south pole will be in the Arctic region and the north pole will be in Antarctica? 


Interview:

John A. Tarduno, Ph.D., Prof. and Chair, Earth and Environmental Sciences Dept., Univ. of Rochester, New York
John A. Tarduno, Ph.D., Prof. and Chair, Earth and Environmental Sciences Dept., Univ. of Rochester, New York

John A. Tarduno, Ph.D., Prof. and Chair of the Earth and Environmental Sciences Department, University of Rochester, Rochester, New York: “We can excavate some of the sites, and it’s just like getting a snapshot of the magnetic field at that time during the cooling from these villages that were burnt. We get both the record of the strength of the magnetic field and the intensity of the magnetic field.

WHEN IT’S DESCRIBED AS BEING ANOMALOUS, LIKE AN ANOMALOUS BLOB IN SOUTH AFRICA THAT IS POSSIBLY RELATED TO THE POTENTIAL THAT THE NORTH AND SOUTH MAGNETIC POLES COULD CHANGE, WHY DOES THIS ANOMALY SEEM TO ANTICIPATE THAT POSSIBILITY?

Well, what we think is happening is that, again, think about the Earth’s magnetic field being generated in liquid iron that is moving in the core of the Earth. So we can think about this as a stream. Now, just imagine that in that stream an eddy has formed. And we think that there is this type of eddy in the flow underneath Africa, and that’s responsible for that reverse flux patch. Now, we think that that eddy has formed because the mantle underneath southern Africa is unusual. It’s unusually dense and probably unusually hot, and that’s actually creating this eddy. So that’s important because the creation of this eddy has now kind of disturbed the magnetic field in this region and created this reverse flux patch and weakened the magnetic field. The magnetic anomaly, that kind of is in the southern part of Africa. The mantle anomaly is larger. It goes well beyond the southern part of Africa into parts of the Indian Ocean and then farther to the north under a large part of Africa.

 

Earth Has Had Many Magnetic Pole Reversals — The Last Was 780,000 Years Ago

The rate of reversals in the Earth’s magnetic field has varied widely over time. 72 million years ago (Ma), the field reversed 5 times in a million years. No fewer than 51 reversals occurred in a 12-million-year period, centering on 15 million years ago. Two reversals occurred during a span of 50,000 years. These eras of frequent reversals have been counterbalanced by a few “superchrons” — long periods when no Earth magnetic reversals took place, such as the Cretaceous Normal superchron in the timeline below.

Geomagnetic polarity since the middle Jurassic. Dark areas denote periods where the polarity matches today's polarity, while light areas denote periods where that polarity is reversed. The Cretaceous Normal superchron is visible as the broad, uninterrupted black band near the middle of the image. The last pole flip was 780,000 years ago.
Geomagnetic polarity since the middle Jurassic. Dark areas denote periods where the polarity matches today’s polarity, while light areas denote periods where that polarity is reversed. The Cretaceous Normal superchron is visible as the broad, uninterrupted black band near the middle of the image. The last pole flip was 780,000 years ago.

SINCE THE LAST TIME THAT THE MAGNETIC POLES CHANGED WAS 780,000 YEARS AGO, COULD YOU EXPLAIN WHY IT IS THAT IN THIS 21ST CENTURY WE ARE SEEING SCIENTIFIC PAPERS OR GENERAL PRESS ABOUT WILL THE MAGNETIC POLES CHANGE THIS CENTURY? IS THERE SOMETHING IN SCIENCE IN ADDITION TO YOUR ELECTROMAGNETIC BLOB UNDER SOUTH AFRICA THAT SEEMS TO BE DRIVING THIS INTEREST IN THE POSSIBILITY THAT WE’RE GOING TO HAVE A MAGNETIC POLE CHANGE YET THIS 21ST CENTURY?

Yeah. First of all, there’s very little chance, I would say almost no chance, that the Earth’s magnetic field is going to reverse polarity in the next 100 years. So why have you seen articles discussing this? You know, we don’t know if the Earth’s magnetic field is going to reverse polarity, and we don’t know that the changes that we’re seeing today are the start of a magnetic reversal. What we do know, however, is that the changes are unusual. The magnetic field is actually changing, dropping in intensity quite rapidly, and that rapid change is very unusual.

And the other thing that is intriguing is the pattern of how the magnetic field is changing. This reverse flux patch that we see underneath South Africa, is actually very similar to what we see in (computer model) numerical simulations of the magnetic field. It’s the type of thing you see before magnetic reversal. So there’s all these types of evidence that would suggest that, OK, this is actually something quite unusual.

Now, what our research has shown is that we think things like the creation of the South Atlantic Anomaly may be a recurrent phenomenon. That we see evidence in the archaeomagnetic record of things like the South Atlantic Anomaly in the past, these same types of magnetic changes. So what we’re seeing today may continue, and there is a small possibility it could really be the beginning of a magnetic reversal.

It could also be the fact that the field will then recover, and some eddy will form in the future that will lead to a reversal. We know enough about the magnetic field to say that these changes do take time. They take time to actually transmit through the mantle. I think the chances of the magnetic field changing in intensity to reversal in the next 100 years is not something that we think is going to happen. However, I should just point out we don’t have to get to the point of a magnetic reversal for there to be societally relevant changes in the magnetic field that we should be concerned about.

CAN YOU EXPLAIN?

 

If Magnetic Anomaly Keeps Weakening, What Happens to Earth Life?

Yeah. So let’s suppose the magnetic field continues to decrease for the next decade to hundreds of years, and that’s certainly well within the realm of possibilities. That means that the magnetic shield of the Earth is decreasing. The effectiveness of the shielding from solar particles, high energy particles that are emitted from the sun. So we can potentially have more damage to satellites we have to worry about. We could potentially have more damage to infrastructure, to power grids during large solar storms. There’s even a possibility if the magnetic field continued to decrease, let’s say was decreased to less than half of what it is today, that we could start to worry about there being atmospheric effects. Now, what happens if we weaken the magnetic field, we can then have some of these solar particles penetrating deeper into the atmosphere. And this can cause kind of a chain reaction of chemical effects that can start to break down ozone. We could then start to see the creation of ozone holes. We could see them at different latitudes. And then of course, this raises the question of increased levels of skin cancer rates.

AND IT HAS DECREASED 15 PERCENT IN THE LAST 400 YEARS?

Yes. In the last 160 years, it’s decreased 9-10 percent or so.

 

Solar Cycles 24, 25 and 26 Could Lead to Maunder Minimum PLUS Weakening Magnetic Field Increasing Cosmic Ray Radiation

IN ANOTHER 10-12 MONTHS, WE’RE GOING TO START ENTERING INTO SOLAR CYCLE 24, AND THERE ARE SOLAR PHYSICISTS WHO ARE TAKING BETS WITH EACH OTHER ABOUT WHETHER 24, 25-26 COULD BE GOING INTO SOMETHING LIKE THE MAUNDER MINIMUM BACK IN THE 1645-1715 TIME PERIOD. AND IF SO, THEY ARE ALREADY CONCERNED ABOUT WHAT IS HAPPENING WITH INCREASING COSMIC RAYS. THERE ARE MEASURMENTS FROM SATELLITES NOW THAT ARE SAYING THAT THE COSMIC RAY RATE IS INCREASING QUITE A BIT, AND THEY WONDER IF IT IS BECAUSE WE ARE HEADED INTO A VERY LOW SUNSPOT CYCLE. DO YOU THINK THAT THERE IS ANY TIE TO THE WORK THAT YOU’RE DOING IN TERMS OF INCREASING COSMIC RAYS NOW?

What I would be most concerned about, and this is not distant from the solar physicists’ predictions, is really the possibility of the very large events. We can talk about background solar activity, but we also should be concerned about the large coronal mass ejection events. I think if we continue to have a weakening magnetic field and we start seeing events like that, yes, I mean, there is reason for some concern.

BECAUSE THE TWO MIGHT COME TOGETHER, MEANING THAT IF WE ARE GOING TO MOVE INTO A MAUNDER MINIMUM TIME PERIOD AT EXACTLY THE SAME TIME THAT THERE ARE MAGNETIC ANOMALIES BECAUSE OUR PLANET MIGHT BE GETTING READY TO DO A MAGNETIC POLE SHIFT IN DECADES OR CENTURIES AHEAD, THAT THE TWO COMBINED COULD MEAN THAT WE COULD HAVE FLUCTUATING MAGNETIC FIELDS THAT ARE GOING DOWN MORE AND MORE.

Well, that’s right, yeah. Any time we have a decreasing magnetic field, we have the potential for coronal mass ejections.

IF THE MAGNETIC FIELDS GO UP AND DOWN LIKE A YO-YO, AND THAT THEY GO DOWN VERY LOW AND THEN BOUNCE BACK UP AND DOWN AND BACK OVER A HUNDRED YEAR PERIOD RIGHT BEFORE A MAGNETIC POLE CHANGE, WHAT WOULD HAPPEN TO EARTH LIFE?

Well, we have as yet found no evidence in the geological record, though we know we’ve had hundreds of reversals. We see no evidence yet of a mass extinction event associated with magnetic reversal.

 

Earth’s Unpredictable Instability

IS IT FAIR TO SAY FROM YOUR POINT OF VIEW THAT WE ARE LIVING ON A VERY UNSTABLE PLANET?

Hm. I…it’s stable, and it’s unstable. (Laughs) I think what we’re finding, if we really want to step back and look at all the marvelous discoveries that are coming out about exoplanets, if we look at what we’re discovering so far about exoplanets, we would have to conclude that we live on a remarkably stable planet.

That probably has a lot to do with why we have life on the planet. We have a large moon that has an incredibly stabilizing effect on the orbit of the planet. We would have much more wild swings in climate if we didn’t have the moon around. So if we compare ourselves to exoplanets, we live on a remarkably stable planet. However, we also live on a dynamic planet. It’s not a dead planet. It’s a planet that is active, and on kind of short time scales, yes, we have geological activity.

 

Gondwanaland to Continents: What Forces Pushed Land Masses Apart?

EARTHQUAKES ARE SUCH A PART OF THE FABRIC OF THIS PLANE. A QUESTION THAT LISTENERS HAVE ASKED ME IS WHAT WOULD HAVE BEEN THE REASON WHY GONDWANALAND, WHEN ALL OF THE LAND MASSES WERE ONE, WHAT WOULD HAVE CAUSED THIS TO START SPREADING APART INTO THE CONTINENTS WE KNOW TODAY? IT SEEMS LIKE SUCH A MASSIVE FORCE WOULD HAVE BEEN INVOLVED AND WHAT WOULD HAVE CAUSED IT?

Gondwanaland 420 million years ago with view centered on South Pole. Illustration by Fama Clamosa.
Gondwanaland 420 million years ago with view centered on South Pole. Illustration by Fama Clamosa.

Well, that’s an interesting point that then gets you back to this question of magma coming up. In that particular case, one of the leading hypotheses is that we have mantle plumes, which don’t melt until they get to the surface, but they are unusually hot mantle that rises from close to the core/mantle boundary that may have ponded beneath the Gondwanan lithosphere and then motivated a large scale rifting in the formation of the Atlantic Ocean.

THEN THERE IS THAT QUESTION OF WHY WOULD THERE HAVE BEEN A CHANGE IN THE PLUME IN THE MANTLE THAT WOULD HAVE CAUSED IT IN THE FIRST PLACE?

Well, it’s probably because the mantle doesn’t cool uniformly, and there can be cycles. Parts of the mantle may be more cooled sufficiently when there may be other parts that start to heat up. And when those regions of the mantle that haven’t cooled off over a sufficiently long amount of time, heat can build up, and we can start potentially having mantle plumes form.”

Other clay research in Italy a few years ago implied that the last pole change occurred in 100 years, with the magnetic field going up and down. Prof. Tarduno says he thinks it would take maybe a thousand years for the change to happen – but based on his newly published work, the persistent weakening of the magnetic field in the South Atlantic Anomaly could have been happening for a thousand years.  So could another big change in this revolutionary time be that the magnetic poles are finally going to start changing in the 21st to 22nd Centuries?

Also see:


More Information:


Websites:

South Atlantic Anomalyhttps://en.wikipedia.org/wiki/South_Atlantic_Anomaly

Reverse Patch Flux and Reversals: Magnetic Flip, British Geological Survey: http://www.geomag.bgs.ac.uk/education/reversals.html

Geophysical Research Letters, January 22, 2018, Prof. John Tarduno: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL076007

Earth Magnetic Reversals Timeline: https://en.wikipedia.org/wiki/Geomagnetic_reversal

“New Data Helps Explain Recent Fluctuations in Earth’s Magnetic Field,” February 27, 2018, Univ. of Rochester Newscenter:
http://www.rochester.edu/newscenter/new-data-helps-explain-recent-fluctuations-in-earths-magnetic-field-302242/

“Does An Anomaly in the Earth’s Magnetic Field Portend A Coming Pole Reversal? February 5, 2017, The Conversation:
https://theconversation.com/does-an-anomaly-in-the-earths-magnetic-field-portend-a-coming-pole-reversal-47528

 


© 1998 - 2018 by Linda Moulton Howe.
All Rights Reserved.