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Author Topic: Can a solar eclipse trigger an earthquake?  (Read 13758 times)

Offline norcalclimber

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Can a solar eclipse trigger an earthquake?
« Reply #25 on: 09/06/2010 16:26:33 »
the effective diameter of the Sun is about 0.5 degree if we exclude gravitational shielding that I think we all do there can be very little difference in the gravitational field on the Earth when it passes 0.26 degree below the centre of the Sun (no eclipse) and when it passes right across the face of the Sun (total eclipse).

Actually, I think we can all agree that there is plenty of difference between an eclipse and no eclipse...since we get our highest tides when we have a solar eclipse, there is absolutely no doubt that there is a significant difference in the force felt by Earth's crust.  Unless perhaps I received poor information on when we have our highest tides?
 

Offline graham.d

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Can a solar eclipse trigger an earthquake?
« Reply #26 on: 09/06/2010 17:39:54 »
I think you may have poor info norcalclimber. Spring tides (the highest and the lowest) occur every 2 weeks when the moon is on the same side as the sun and again when the moon is on the opposite side from the sun. An eclipse only affects a small area of the earth's surface and the difference of the force produced when the alignment is so exact from when it is not is very small indeed, though possibly not totally negligible. The biggest effect will be due to the eliptic nature of the moon's orbit and the biggest tides arise when the moon is closest.
 

Offline norcalclimber

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Can a solar eclipse trigger an earthquake?
« Reply #27 on: 09/06/2010 17:54:30 »
I think you may have poor info norcalclimber. Spring tides (the highest and the lowest) occur every 2 weeks when the moon is on the same side as the sun and again when the moon is on the opposite side from the sun. An eclipse only affects a small area of the earth's surface and the difference of the force produced when the alignment is so exact from when it is not is very small indeed, though possibly not totally negligible. The biggest effect will be due to the eliptic nature of the moon's orbit and the biggest tides arise when the moon is closest.

It is very possible my info/understanding is poor, as in this case it comes from watching some program(don't remember which) on Discovery channel/or Science channel.  I was aware that spring tides are highest, but I feel certain the program I watched also stated that tides during Total Solar eclipses are even higher than spring tides?  I completely agree with you regarding the biggest effect being when the moon is closer, and during a total solar eclipse the moon is closer than during other eclipses as well as having the added benefit of the Suns gravitational field lined up.  I still think the effect could be quite large from them being lined up, going back to the p.s.i. example; even a very small p.s.i. over a large area is significant, and in the case of an eclipse it seems to me that if it is focused over a hot spot it may be easily enough of a difference to be the proverbial straw which broke the camels back.
 

Offline LeeE

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Can a solar eclipse trigger an earthquake?
« Reply #28 on: 11/06/2010 12:52:50 »
Ah yes, science programs of TV.  Sadly, their desire to overdramatise things sometimes gets in the way of accuracy, even to the extent of becoming misleading at best, and sometimes just getting it plain wrong.

Lol - I was just going to give an example of such a mistake that I saw in one of these programs, and was going to post the Wikipedia link for the real meaning only to find that Wikipedia has currently got it wrong too - oops  ;D

The example I was going to give concerned a phenomenon known as the Iron Catastrophe.  According to this particular TV science program (and Wikipedia too) the term Iron Catastrophe refers to the migration of iron down towards the core of the Earth when the planet was still molten, which is really not much of a catastrophe, seeing as it caused no problems for anyone or anything and it didn't happen with sudden rapidity; catastrophe just isn't the right word to describe it.

In fact, the term more correctly refers to the point in a nova when all of the elements lighter than iron have been fused and the sudden and catastrophic collapse of the star occurs.  Up to the point of the Iron Catastrophe, the fusion of the elements lighter than iron still releases sufficient energy to prevent the collapse of the star against its own gravity.  Fusion of iron though, requires energy, so when the star starts fusing iron at its core it also starts sapping the energy preventing its collapse due to gravity.  As a result, the final collapse of the star is both very quick, and from the star's point of view, most certainly catastrophic.
 

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Can a solar eclipse trigger an earthquake?
« Reply #28 on: 11/06/2010 12:52:50 »

 

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