Earth Magnetic Field Reversal 2

[Laplacian]

A while back, I was watching a program on one of the "Learning Channels" that mentioned evidence of Earth's magnetic field reversals (several) oberved in lava deposits on ocean floors.

If these reversals really did happen, it couldn't have been instantaneously for each event. Did it take days, months, or years? What were the effects of cosmic radiation during the field collapse? What happened to animals dependant on the field for navigation? I haven't Googled yet, a different topic on the motor forum reminded me of the question.

 

[Comcokid]

There have been several science programs on this subject. The field switches directions every few thousand years or more. It weakens for about 100 years before it 'flops', and in the transision, multiple magnetic poles may occur. Currently, we are in a phase of weakening, and the current N/S pole location has been long one in geographic history.

One PBS Nova program brought up the fact that lava deposites in Oregon(?) investigated by one researcher indicated that during a past transision phase the field may have reversed almost several times a week before settling down.

There has been a past Eng-tips tread on this issue.

 

[0707]

What happens in the exact moment of earth reverse polarity?

Maybe we will suffer a radiation peak. Maybe boats, planes and birds will get lost. Maybe it will cause disturbance of Coriolis force and because of that we will have an increase or change of hurricanes occurrence.

If earth reverse polarity coincides with a solar flare all the above occurrences will be potentated

“NASA predicts that, rather than declining to zero gauss, the magnetic field would become disordered. Thus we might for short time have more than one north and South Pole on the planet. This official scientific stance says that the magnetosphere, which shields us from cosmic radiation, would not entirely disappear either. Thus, while communications would be erratic and perhaps at times completely inactivated, humans would find ways to survive. However, there are dissenters in the ranks, pointing to the vast South Atlantic magnetic anomaly and radiation damage to satellites over that region attributed to weakening of the protective magnetosphere.”

luis marques

 

[SomptingGuy]

What happens in the exact moment of earth reverse polarity?

Global warming will be blamed.

 

[michfan]

Oh, I think they'll blame it all on Al Gore.
Once he invented the internet, it was all over for him.

 

[BJC]

The program I saw said that during the shift of poles there would be a period of a 1000 years of so where the earth might have 8 or more poles ( 4 north and 4 south ) and that they would shift around. The shielding effect that the poles give the earth would be deminished in that period. If a new pole developed under your town you could expect more radiation, more cancer etc.
A lot of migratory birds would also be confused.

 

[Comcokid]

In a way, you might say we already have another pole. For years, there has been a "South Atlantic anomaly" which low-earth orbiting satellites have had to deal with. This is a weak spot in the magnetic field which allows charged particles to get closer to the earth than they might otherwise (affecting low earth-orbit satellites). This anomaly has been growing. It might eventually become the new "magnetic north" pole.

 

[Laplacian]

The discussion I would like to get started is to what degree does Earth's magnetic field limit solar radiation absorption on Earth'surface? Would a weaker field on Earth allow more solar radiation through causing increased temperatures, skin cancer, etc.?

 

[0707]

During earth reverse polarity maybe we will suffer a radiation peak by interaction with radiation that travels through vacuous space at the speed of light and propagates by the interplay of oscillating electric and magnetic fields (electromagnetic radiation "photoionization"). This ionisation is of course dangerous for humans and can led to skin cancer.

 

[hydromech]

This polar inversion was sponsored by L'Oreal Sun Protection Products...because you're all worth it.

 

[CajunCenturion]

And if you thought global warming is a polarizing topic ...

Good Luck
--------------
As a circle of light increases so does the circumference of darkness around it. - Albert Einstein

 

[kenvlach]

On the bright side, the shift in magnestism will bring the aurora borealis (the Northern Lights) and the aurora australis (the Southern Lights) away from the Arctic & Antarctic toward population centers, allowing a major reduction in electricity usage for lighting. Maybe save 1 x 10¹² watts, since "the auroras "dance," moving along with the atmospheric currents that can reach 20,000,000 amperes at 50,000 volts." --

http://science.howstuffworks.com/question471.htm

The consequent reduction in electrical generation will stop or slow global warming!!!

Aurora over Lake Superior, phtographed by Michael T. Dolan

http://www.geo.mtu.edu/weather/aurora/images/aurora/

 

[0707]

hydromech

in some situations vaselin would also works.

 

[ScottyUK]

So all we need is some long cables into the upper atmosphere and the world's energy crisis is solved.

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Sometimes I only open my mouth to swap feet...

 

[davefitz]

Back in the 1960's, it was found that there is a layer of mocrotecktites in the soil at a depth exactly coresponding to the same time as the poles reversed. In the 1960's , it was thought that the microteckties were caused by the impact of meteors, but current thinking is that the glassy particles are spewed from volcnoes that become active during the pole reversal. I'm not sure which is the least habit forming event.

I have also heard that the 20,000 yr schedule for these events corresponds to this solar system's oscillating orbit thru a layer of the milky way.