What would a magnetosphere polarity shift do to Earth's Van Allen Belt?

Question

As I understand it the Van Allen Belt is a belt of radioactive particles trapped by Earth's magnetosphere. As I understand a magnetosphere polarity shift Earth will lose its magnetic sphere for a short period. Without a magnetic field to hold them their the radiation would dissipate right?

Answer 1

The van Allen belt contains the souls of all departed mankind. When the polarity shifts, the ones who had been bound for Heaven will, instead, be bound for h**l. And vice versa.

Answer 2

  Well, using my knowledge on astronimcal stuff. I have come to the finl conclusion which that i have not a single idea what you are talking about. because i am not very smart.... =(

Answer 3

Well, essentially, the particles that the van Allen belts now trap & divert will plow straight in to our atmosphere. Solar wind, cosmic rays, stray charged particles,now diverted around the Earth, will all come into direct, high-speed contact with the atmosphere, and life on the surface.

It's been predicted that cancer rates will go up, and smog will increase for a time, until it can re-establish itself again.  

Answer 4

The magnetic poles move all the time.

There is a geologic record that shows it has happened many times in our past but not at regular intervals. Time between reversals can be 10000 yrs or a million years.

However - we know that the magnetic field does not collapse in the process - if it did, there would be major extinctions that correlate with the geologic record for pole reversals - there is no correlation.

The latest hypothesis is that the Earth's magnetic field gets chaotic, with lots of north and south poles - so we still have a magnetic field, but compasses will be useless. And then it straightens itself back out, but with north and south reverse.

This is actually similar to what the sun does - but the sun does it on a regular 11 year cycle.

By the way - the you need to be careful how you describe the particles in the Van Allen belts - radioactive implies something like Uranium that decays by spewing out nuclear particles (alphas, betas)

But the particles in the van Allen belts are largely protons (hydrogen nuclear, electrons - which are beta particles and helium nuclei - which are alpha particles). Sorry to be so pedantic, but we have to be careful in the terms we use.

Answer 5

The solar wind itself is not strong enough to blow away Earth's gaseous atmosphere.

The magnetic field of Earth indeed holds particles trapped, and if that field should suddently disappear then there would be nothing to hold those particles in place.  Good thing the chances of that happening are about the same as a fish in your ear translating Vogon into English.

EDIT 1:

I'm voting up Stardust for her care in explaining the difference between radiation and the Van Allen belts.  The Van Allen belts are composed of charged particles.  The electrical charge is what makes them susceptible to Earth's magnetic field, but is not the reason they are considered hazardous.

Particles have a potential for radiological effect when they move rapidly.  High-velocity particles (charged or not) create a sort of radiation.  When those particles hit things, they ionize them and have many of the same biological effects as gamma rays and x-rays: more familiar forms of radiation.  The particles in the Van Allen belt, and elsewhere in space, can have high "energies" (velocities) and that's what poses the hazard.

Radioactivity from things like plutonium or uranium is a very different thing.  It's the product of radioisotopic decay, which has nothing to do with the Van Allen belts or cosmic radiation.

Answer 6

i assume it would meet the same fate as our atmosphere.... that of being blown away by solar winds.

we've never been around for one... atmosphere could be blown away when the shift reaches mid-point and the field is at it's weakest... if the field disappeared entirely, the atmosphere would indeed be blown away by solar winds, why is it so hard to imagine that some of the atmosphere will be lost when the field is really weak? (and it does get very very weak....)