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Tim_the_geek t1_ja9ghvr wrote

Reply to comment by vwb2022 in Magnetic pole reversal by Gopokes91

I respectfully disagree with one of your points. You say there will be no effect on the Earth's rotation if the magnetic pole shifts. I feel that there is quite a bit of "new magnetic" material on earth that was created during the current pole locations. These magnetic rocks in the crust have a polarity, when the core's magnetic field changes, I feel that the portions of the crust that have magnetic material in them will seek to realign with the NEW N-S orientation causing the earth's crust (or sections) to move.

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AnarchistAccipiter t1_ja9h6qw wrote

No.

The magnetic poles wander all the time, no parts of the earth's crust are affected.

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capt_yellowbeard t1_ja9jwg1 wrote

Succinct and well stated.

I’ll add that there is clear alignment “striping” of magnetic particles on the ocean floor. So by drilling different parts of the sea floor one can see which direction north and south were when the magma that makes up the sea floor was deposited. Once it solidifies, however, no further change occurs.

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supersonicpotat0 t1_ja9ksfm wrote

There is a easy way to test for this. Set a magnet on your desk. Now, rotate it 180 degrees, and set it down again.

Does the magnet suddenly snap back to its original position, or otherwise slide over your desk in search of magnetic north? You are probably (correctly) thinking this is a ridiculous experiment. It's obvious that earth's magnetic field is not strong enough to do stuff like that.

So, if the earth's magnetic field is too weak to even move a unsecured magnet that probably only weighs a few grams, you're expecting it to affect a billion tons of rock in the form of continental plates?

You can even see a complete absence of effect ib the exact same rocks you are referencing. These rocks provide evidence of past pole reversals, because different layers have different alignments.

If the polarized rock moved into alignment when the fields shifted, new layers would always be deposited with the same alignment as the old ones. The only reason these rocks are even referenced in the same breath as pole realignments is because this doesn't happen, and cannot happen.

Finally, to see how magnetic the average rock is, obtain a compass, a magnet, and a piece of gravel. Gravel is made exclusively from the least valuable (e.g. Most common) form of rock readily available, so it is a good stand in for the average composition of the earth's crust.

Find the furthest distance you can that leads the compass to point towards the magnet, rather than magnetic north. If the compass is pointing at the magnet, this means it's feild is dominating over the earth's field at that distance. Replace the compass with gravel. Does the gravel slide towards the magnet at this distance? If not, this shows that the magnetic minerals in the rock are insufficient to move it, despite being in the presence of a local magnetic field strong enough to dominate over the earth's natural field (as shown by the compass)

We routinely experience magnetic fields thousands of times stronger than the earth's own, and nothing tends to happen. The same is true of most rocks.

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Eidalac t1_jaakt3h wrote

There would need to be a critical mass of highly magnetic material in the crust, and it would have to be highly polarized and the flip would have to happen extremely fast to have any impact on the crust at scale.

Most highly magnetic material is in the core (iron) while the crust is mostly silicates which don't care about the field all that much.

The stuff that is magnetic wouldn't be polarized enough to prefer one pole to the other. There would be equal "north" and "south " pull.

Lastly the flip is thought to take around 2-12k years, with the magnetic field flickering and changing over that time

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Low-Restaurant3504 t1_ja9tpd8 wrote

That's not how any of that works, at all... like, I don't mean to be rude, but seriously, no. That's an idea even Roland Emmerich would pass on.

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