Switching Poles...

[Jay-qu]

I just started leaning about magnets at school and came across and interesting fact, Earths magnetic field changes! It has been proved that the magnectic field has frequently switched so that our north pole was south and vise versa, the next interesting part is that we are due for another change in the next 1000-2000 years

this is bad news because earths magnetic field protects us from a lot of the suns harmful radiation... but im sure we can come up with an alternate solution when push comes to shuv

[UncleAl]

but im sure we can come up with an alternate solution

http://www.es.ucsc.edu/~glatz/geodynamo.html

http://www.psc.edu/science/Glatzmaier/glatzmaier.html

http://www-geol.unine.ch/cours/geol/coredynamo.pdf

http://www.agu.org/revgeophys/roberp01/node5.html

http://www.jhu.edu/~eps/geoplab/geophys/dynamovie.html

 

No.

[Boerseun]

I just started leaning about magnets at school and came across and interesting fact, Earths magnetic field changes! It has been proved that the magnectic field has frequently switched so that our north pole was south and vise versa, the next interesting part is that we are due for another change in the next 1000-2000 years

this is bad news because earths magnetic field protects us from a lot of the suns harmful radiation... but im sure we can come up with an alternate solution when push comes to shuv

If you look at any proper map, it'll show you the magnetic variance to proper North, and the annual shift. Magnetic North is quite a distance from True North, and keeps on moving, as the Earth's guts keep on churning. This shift is well-documented, although, with the advent of GPS this addendum to maps might dissapear - its only usefull for Boy Scouts using magnetic compasses.

[Aki]

Think the birds would have a hard time adjusting?

[Jay-qu]

but its not just the boy scouts, what about the electrically charged particals and radiation from the sun? would we be in danger?

[Boerseun]

but its not just the boy scouts, what about the electrically charged particals and radiation from the sun? would we be in danger?

Definitely.

The magnetic field forces the solar wind away from Earth, leaving the auroras in the polar regions the only evidence that we are being hammered with high-speed particles from the sun.

If the poles shift, and the magnetic field loses its uniform shape, it'll last a couple of years before it becomes stable again, opening holes whereby the solar wind can penetrate the atmosphere in much lower latitudes - you'll get amazing auroras in the Bahamas, for instance. This might lead to higher incidences of skin cancer, etc.

Birds have been shown to navigate by sight, the stars, etc. - if you release birds in a planetarium, and you move the constellations, the birds follow suit and fly in the wrong direction. However, these studies haven't been made on all species, and there might be birds that navigate using the Earth's magnetic field. But, according to studies on ferrous deposits, the particles show a regular North/South orientation and an abrupt South/North orientation, indicating that the polar flip is a regular occurence. This being the case, any birds dependent on magnetic navigation should have had problems long ago, leaving only those navigating by sight or other means to continue the line.

I think we'll encounter issues with satellites which are also protected by the magnetic field, suddenly being exposed to a much higher radiation flux.

[msisk]

hah, isn't earth cool? that it does such crazy things like that

[jasonchild]

Think the birds would have a hard time adjusting?

 

Perhaps the ones who survive the crispy-critters solar bath will.

[Fishteacher73]

Perhaps these shifts that have windows that allow lots of harmful radiation may be one of the keys in explaining genetic mutations for evolution? This would greatly increase the mutation rate above the "normal" and could perhaps be yet another mechanism for change.

[Harzburgite]

Perhaps these shifts that have windows that allow lots of harmful radiation may be one of the keys in explaining genetic mutations for evolution? .

This has been considered, however there is no correlation between periods of accelerated evolution and polar reversals. Unfortunately I do not recall the reference for this work: it may have been in Science in the late 90s.

[Turtle]

It seems the geomagnetic flip may have a predictable periodicity according to this new article.

http://physicsweb.org/articles/news/10/3/15/1

Beyond explaining using a different distribution, the article lists a number of real concerns for humans during a magnetic reversal. Good stuff Maynard.:friday:

[Eclogite]

Beyond explaining using a different distribution, the article lists a number of real concerns for humans during a magnetic reversal. Good stuff Maynard.:)

The research paper itself(http://lanl.arxiv.org/PS_cache/physics/pdf/0603/0603086.pdf) does not address anything about the effects. The comments on the possible effects of such a reversal have been added by the review writer. The only two effects mentioned are: As well as affecting the migration trajectories of birds and other animals, the disruption to the Earth's magnetic field could expose the Earth to hazardous cosmic rays.

 

(The emphasis is mine.) Has anyone seen any research that actually demonstrates a probable effect on the biosphere, other than on migration? To date all I have been able to find are throw away comments, such as the ones in this article, with no evidence offered to justify the claim, no research cited.

[Zythryn]

Has anyone seen any research that actually demonstrates a probable effect on the biosphere, other than on migration? To date all I have been able to find are throw away comments, such as the ones in this article, with no evidence offered to justify the claim, no research cited.

 

The April 2005 issue of Scientific American has an article on the reversals. I will see if I can find more info on it, I suspect they cite a number of research programs.

 

edit* link added: http://www.scientificamerican.com

[Eclogite]

I read it. I have it somewhere around. My recollection is that it focused entirely on the mechanism of the generation of the field and the cause of the reversals. The researchers were running a complex FE analysis to simulate the behaviour of the convection currents in the outer core. They were able to accurately simulate the pattern and characteristic of past reversals.

 

There was no discussion of the effects of a reversal on the biosphere.

[Turtle]

There was no discussion of the effects of a reversal on the biosphere.

 

Keep looking. Earth's magnetic field is part of our protection from solar radiation. Deadly solar radiation. The pole shift models indicate the field weakens during the shifting; weakened fields mean more radiation.

Last year (during solar minimum no less) the Sun threw off an X class event that was simply off the chart; X60 or some such last I heard. Now that we have reached solar minimum, it only goes up from here. A smaller event caused the power blackout in Canada in 1989, so these events do affect humanity negatively.

Couple weakend magnetic fields with solar maximum & you get serious radiation problems for all biota.

[Eclogite]

Keep looking. Earth's magnetic field is part of our protection from solar radiation. Deadly solar radiation.

It doesn't protect us at the poles, and there the radiation level from cosmic rays is only marginally higher than elsewhere on the planet. Aplha particles, protons and electrons would be an issue, but most of them get stopped by the atmosphere. UV gets cut out by the ozone layer. So, I ask again, which solar radiation is the magnetic field protecting us from?

[InfiniteNow]

So, I ask again, which solar radiation is the magnetic field protecting us from?

 

 

http://csep10.phys.utk.edu/astr161/lect/earth/magnetic.html

The solar wind mentioned above is a stream of ionized gases that blows outward from the Sun at about 400 km/second and that varies in intensity with the amount of surface activity on the Sun. The Earth's magnetic field shields it from much of the solar wind. When the solar wind encounters Earth's magnetic field it is deflected like water around the bow of a ship, as illustrated in the adjacent image