[b][url=http://www.universetoday.com/2008/10/03/2012-no-geomagnetic-reversal/]2012: No Geomagnetic Reversal[/url][/b]
Written by [url=http://www.universetoday.com/author/ian/]Ian O'Neill[/url]
[url=http://www.universetoday.com/wp-content/uploads/2008/10/doomsday_magnetic1.jpg][img(234px,250px)]
http://www.universetoday.com/wp-content/uploads/2008/10/doomsday_magnetic1-234x250.jpg[/img][/url][i]Apparently,on December 21st 2012, our planet will experience a powerful event.
This time we’re not talking about Planet X, Nibiru or a “killer” [url=http://www.universetoday.com/guide-to-space/the-sun/solar-flares/]solar flare[/url],
this event will originate deep within the core of our planet, forcing a
catastrophic change in our protective magnetic field. Not only will we
notice a rapid reduction in magnetic field strength, we’ll also see the
magnetic poles rapidly reverse polarity (i.e. the north magnetic pole
will be located over the South Pole and [i]vice versa[/i]). So what
does this mean to us? If we are to believe the doomsayers, we’ll be
exposed to the vast quantities of radiation blasting from [url=http://www.universetoday.com/guide-to-space/the-sun/]the Sun[/url];
with a reversing magnetic field comes a weakening in the Earth’s
ability to deflect cosmic rays. Our armada of communication and
military satellites will drop from orbit, adding to the chaos on the
ground. There will be social unrest, warfare, famine and economic
collapse. Without GPS, our airliners will also plough into the ground[/i]…
[list]
[*][url=http://www.universetoday.com/2008/05/19/no-doomsday-in-2012/] 2008)[/url]
[/list]
Using the Mayan Prophecy as an excuse to create new and explosive
ways in which our planet may be destroyed, 2012 doomsayers use the
geomagnetic shift theory as if it is set in stone. Simply because
scientists have said that it [i]might[/i] happen within the next millennium appears to be proof enough that it [i]will[/i]
happen in four years time. Alas, although this theory has some
scientific backing, there is no way that anyone can predict when
geomagnetic reversal might happen to the nearest day or to the [i]nearest million years[/i]…
Firstly, let’s differentiate between [i]geomagnetic reversal[/i] and [i]polar shift[/i]. [b]Geomagnetic reversal[/b]
is the change in the magnetic field of the Earth, where the magnetic
north pole shifts to the South Polar Region and the south magnetic pole
shifts to the North Polar Region. Once this process is complete, our
compasses would point toward Antarctica, rather than northern Canada. [b]Polar shift[/b] is considered to be a less likely event that occurs a few times in the evolutionary timescale of [url=http://www.universetoday.com/guide-to-space/the-solar-system/]the Solar System[/url]. There are a couple of examples of planets that have suffered a catastrophic polar shift, including [url=http://www.universetoday.com/guide-to-space/venus/]Venus[/url]
(which rotates in an opposite direction to all the other planets,
therefore it was flipped upside down by some huge event, such as a
planetary collision) and [url=http://www.universetoday.com/guide-to-space/uranus/]Uranus[/url] (which rotates on its side, having been [url=http://www.universetoday.com/2008/08/18/ten-mysteries-of-the-solar-system/]knocked off-axis by an impact, or some gravitational effect[/url] caused by [url=http://www.universetoday.com/guide-to-space/jupiter/]Jupiter[/url] and [url=http://www.universetoday.com/guide-to-space/saturn/]Saturn[/url]).
Many authors (including the doomsayers themselves) often cite both
geomagnetic reversal and polar shift as being one of the same thing.
This isn’t the case.
[i]So, on with geomagnetic reversal[/i]…
[b]How often does it happen?[/b]
[url=http://www.universetoday.com/wp-content/uploads/2008/10/earth_interior.jpg][img(250px,187px)]
http://www.universetoday.com/wp-content/uploads/2008/10/earth_interior-250x187.jpg[/img][/url]The Earths interior (University of Chicago)
The
reasons behind the reversal of the magnetic poles is poorly understood,
but it is all down to the internal dynamics of Planet Earth. As our
planet spins, the molten iron in the core flows freely, forcing free
electrons to flow with it. This convective motion of charged particles
sets up a magnetic field which bases its poles in the North and South
Polar Regions (a dipole). This is known as the [i][url=http://en.wikipedia.org/wiki/Dynamo_theory]dynamo effect[/url][/i]. The resulting magnetic field approximates a bar magnet, allowing the field to envelop our planet.
This magnetic field passes through the core to the [url=http://www.universetoday.com/guide-to-space/earth/earths-crust/]crust[/url] and pushes into space as the Earth’s magnetosphere, a protective bubble constantly being buffeted by the [url=http://www.universetoday.com/guide-to-space/the-sun/solar-wind/]solar wind[/url].
As the solar wind particles are usually charged, the Earth’s powerful
magnetosphere deflects the particles, only allowing them into the polar
cusp regions where the polar magnetic fieldlines become “open.” The
regions at which these energetic particles are allowed to [url=http://www.universetoday.com/2008/07/28/behind-the-power-and-beauty-of-northern-lights/]enter glow as aurorae[/url].
Usually this situation can last for aeons (a stable magnetic field
threaded through the North and South Polar Regions), but occasionally,
the magnetic field is known to reverse and alter in strength. Why is
this? [url=http://www.universetoday.com/wp-content/uploads/2008/10/lowrie.gif][img(156px,250px)]
http://www.universetoday.com/wp-content/uploads/2008/10/lowrie-156x250.gif[/img][/url]A
chart showing Earths polarity reversals over the last 160 million
years. Black = normal polarity, White = reversed polarity. From Lowrie
(1997)
Again, we simply do not know. We do know that this magnetic pole
flip-flop has occurred many times in the last few million years, the
last occurred 780,000 years ago according to ferromagnetic sediment. [url=http://www.howtosurvive2012.com/htm_night/pole_02.htm]A few scaremongering articles[/url] have said geomagnetic reversal occurs with “clockwork regularity” - [i]this is simply not true[/i]. As can be seen from the diagram ([i]left[/i]),
magnetic reversal has occurred fairly chaotically in the last 160
million years. Long-term data suggests that the longest stable period
between magnetic “flips” is nearly 40 million years (during the
Cretaceous period over 65 million years BC) and the shortest is a few
hundred years.
Some 2012 theories suggest that the Earth’s geomagnetic reversal is connected to the natural 11-year [url=http://www.universetoday.com/guide-to-space/the-sun/solar-cycle/]solar cycle[/url].
Again, there is absolutely no scientific evidence to support this
claim. No data has ever been produced suggesting a Sun-Earth magnetic
polarity change connection.
So, already this doomsday theory falters in that geomagnetic reversal [i]does not occur[/i]
with “clockwork regularity,” and it has no connection with solar
dynamics. We are not due a magnetic flip as we cannot predict when the
next one is going to occur, magnetic reversals occur at [i]seemingly random points in history[/i].
[b]What causes geomagnetic reversal?[/b]
[url=http://www.universetoday.com/wp-content/uploads/2008/06/model_earth.jpg][img(224px,224px)]
http://www.universetoday.com/wp-content/uploads/2008/06/model_earth.jpg[/img][/url]The model Earth, can a magnetic field be modelled in the lab? (Flora Lichtman, NPR)
Research
is afoot to try to understand the internal dynamics of our planet. As
the Earth spins, the molten iron inside churns and flows in a fairly
stable manner for millennia. For some reason during geomagnetic
reversal, some instability causes an interruption to the steady
generation of a global magnetic field, causing it to flip-flop between
the poles.
In a [url=http://www.universetoday.com/2008/06/02/how-do-you-model-the-earths-magnetic-field-build-your-own-baby-planet/]previous Universe Today article[/url],
we discussed the efforts of geophysicist Dan Lathrop’s attempts to
create his own “model Earth,” setting a 26 tonne ball (containing a
molten iron analogue, sodium) spinning to see if the internal motion of
the fluid could set up a magnetic field. This huge laboratory
experiment is testament to the efforts being put into understanding how
our Earth even generates a magnetic field, let alone why it randomly
reverses.
[url=http://en.wikipedia.org/wiki/Richard_A._Muller]A minority view[/url]
(which, again is used by doomsayers to link geomagnetic reversal with
Planet X) is that there may be some external influence that causes the
reversal. You will often see associated with the [url=http://www.universetoday.com/2008/06/19/2012-planet-x-is-not-nibiru/]Planet X/Nibiru claims[/url] that should this mystery object encounter the [url=http://www.universetoday.com/guide-to-space/the-solar-system/inner-solar-system/]inner Solar System[/url]
during its highly elliptical orbit, the magnetic field disturbance
could upset the internal dynamics of the Earth (and the Sun, possibly
generating that “killer” solar flare [url=http://www.universetoday.com/2008/06/21/2012-no-killer-solar-flare/]I discussed back in June[/url]).
This theory is a poor attempt to link several doomsday scenarios with a
common harbinger of doom (i.e. Planet X). There is no reason to think
the strong magnetic field of the Earth can be influenced by [i]any[/i] external force, let alone [url=http://www.universetoday.com/2008/05/25/2012-no-planet-x/]a non-existent planet[/url] (or was that a [url=http://www.universetoday.com/guide-to-space/stars/brown-dwarf/]brown dwarf[/url]?).
[b]The magnetic field strength waxes and wanes…[/b]
[url=http://www.universetoday.com/wp-content/uploads/2008/10/geomagnetism_western_us.png][img(200px,250px)]
http://www.universetoday.com/wp-content/uploads/2008/10/geomagnetism_western_us-200x250.png[/img][/url]Variations
in geomagnetic field in western US since last reversal. The vertical
dashed line is the critical value of intensity below which Guyodo and
Valet (1999) consider several directional excursions to have occurred.
[url=http://www.usnews.com/articles/science/environment/2008/09/25/why-earths-magnetic-field-flip-flops.html?PageNr=1]New research into the Earth’s magnetic field[/url] was published recently in the September 26th issue of [i][url=http://www.sciencemag.org/]Science[/url][/i],
suggesting that the Earth’s magnetic field isn’t as simple as we once
believed. In addition to the North-South dipole, there is a weaker
magnetic field spread around the planet, probably generated in the
outer [url=http://www.universetoday.com/guide-to-space/earth/core-of-the-earth/]core of the Earth[/url].
The Earth’s magnetic field is measured to vary in field strength and
it is a well known fact that the magnetic field strength is currently
experiencing a downward trend. The new research paper, co-authored by
geochronologist Brad Singer of the University of Wisconsin, suggests
that the weaker magnetic field is critical to geomagnetic reversal.
Should the stronger dipole (north-south) field reduce below the
magnetic field strength of this usually weaker, distributed field, a
geomagnetic reversal is possible.
“[i]The field is not always stable, the convection and the nature
of the flow changes, and it can cause the dipole that’s generated to
wax and wane in intensity and strength[/i],” Singer said. “[i]When it
becomes very weak, it’s less capable of reaching to the surface of the
Earth, and what you start to see emerge is this non-axial dipole, the
weaker part of the field that’s left over[/i].” Singer’s research
group analysed samples of ancient lava from volcanoes in Tahiti and
Germany between 500,000 and 700,000 years ago. By looking at an
iron-rich mineral called magnetite in the lava, the researchers were
able to deduce the direction of the magnetic field.
The spin of the electrons in the mineral is governed by the dominant
magnetic field. During times of strong dipolar field, these electrons
pointed toward the magnetic North Pole. During times of weak dipolar
field, the electrons pointed to wherever the dominant field was, in
this case the distributed magnetic field. They think that when the
weakened dipolar field drops below a certain threshold, the distributed
field pulls the dipolar field off-axis, causing a geomagnetic shift.
“[i]The magnetic field is one of the most fundamental features of the Earth[/i],” Singer said. “[i]But
it’s still one of the biggest enigmas in science. Why [the flip]
happens is something people have been chasing for more than a hundred
years[/i].”
[b]So, no doomsday then?[/b]
Geomagnetic reversal is an engrossing area of geophysical research that
will continue to occupy physicists and geologists for many years to
come. Although the dynamics behind this event are not fully understood,
there is [i]absolutely no scientific evidence[/i] supporting the claim that there could be a geomagnetic reversal around the time of December 21st, 2012.
Besides, the effects of such a reversal have been totally
over-hyped. Should we experience geomagnetic reversal in our lifetimes
(which we probably won’t), it is unlikely that we’ll be cooked alive by
the Solar Wind, or be wiped out by cosmic rays. It is unlikely that
we’ll suffer any mass extinction event (after all, early man, [i]homo erectus[/i],
lived through the last geomagnetic shift, apparently with ease). We’ll
most likely experience aurorae at all latitudes whilst the dipolar
magnetic field settles down to its new, reversed state, and there might
be a small increase in energetic particles from space (remember, just
because the magnetosphere is weakened, doesn’t mean we wont have
magnetic protection), but we’ll still be (largely) protected by our
thick atmosphere.
Satellites may malfunction and migrating birds may become confused, but to predict world collapse is a hard pill to swallow.
[b]In conclusion:[/b]
[list]
[*]Geomagnetic reversal is chaotic in nature. There is no way we can predict it.
[*]Simply because the magnetic field of the Earth is weakening does
not mean it is near collapse. Geomagnetic field strength is “above
average” if we compare today’s measurements with the last few million
years.
[*]The magnetic poles are not set in geographical locations, they move
(at varying speeds) and have done ever since measurements began.
[*]There is no evidence to suggest external forcing of internal
geomagnetic dynamics of the Earth. Therefore there is no evidence of
the solar cycle-geomagnetic shift connection. Don’t get me started on
Planet X.
[/list]
So, do you think there will be a geomagnetic reversal event in 2012? [i]I thought not[/i].
Once again, we find another 2012 doomsday scenario to be flawed in
so many ways. There is no doubt that geomagnetic reversal will happen
in the future for Earth, but we’re talking about time scales anything
from an optimistic (and unlikely) 500 years to [i]millions of years[/i], certainly not in the coming [i]four years[/i]…
Home 
Calendar
