|and the conspiracy theorists are having a heyday... on Mar 09, 2010 @ 01:50 pm|
I have a personal theory on all of this, but I also suspect this is just "one of those things". Is it really that much more than usual, or are we simply more aware?
Based on my limited knowledge of the global warming debate (and I do have a degree in environmental science), I think we can rule that one out. What's my personal theory? I don't think I'll say just yet...
|bring out the geek on Mar 09, 2010 @ 02:03 pm|
There is a theory out there, while not proven, is fairly accepted. The theory is not the end all be all predictor of earthquake activity, but I would definitely say its a trigger mechanism.
If you can think back to your basic physics class, all bodies have mass. So think of Earth, the moon, and the sun. All 3 bodies have considerable mass that each exert gravitation force on one another. We know this, for example, in how the moon controls our tides. As Earth rotates around the sun and the moon rotates around Earth, the rotational paths are not circular, but rather oblate, like an oval. This means that at some point along a rotation path the bodies are closer to each other, reaching their closest proximity, a term called perigee. When the bodies are at perigee that's when they'll exert the most force on each other. So Earth-Sun perigee is in winter. Earth-Moon perigee happens every month, roughly (the lunar cycle).
On top of the perigee phenomenon, there is also the full moon and new moon trigger. When we see a new moon (no moon), Earth is lined up b/t the Sun and moon (our shadow from the sun is cast over the moon, so we can't see it. So that would mean the sun is pulling on Earth in one direction and the moon is pulling on Earth in a different direction (albeit entirely different forces since the Sun's pull is much stronger than that of the moon). When we see a full moon, the moon is lined up b/t the sun and Earth. That means both the sun and the moon are pulling on the Earth from the same direction.
Either way, if you look back in earithquake history you'll see that A LOT of the major quakes have been coincident w/ either a full moon, new moon, moon perigee, or sun perigee. It certainly is not a necessary ingredient to trigger an earthquake, but it certainly is too common to be a coincidence.
If you made it through my geek-dom, you rock!!
|Perigee on Mar 10, 2010 @ 07:25 am|
Spotty -- I read your response twice. My brain cells thank you.
|Spotty - i learned something today! on Mar 10, 2010 @ 08:51 am|
Wow. I was so intrigued by your response i read it twice too! Very informative and easy to understand.
|not global climate change, imo on Mar 10, 2010 @ 09:03 am|
As a professional meteorologist, I do not think global climate change has any bearing on the recent earthquake activity.
However, there is a little bit of evidence out there to support the phrase "earthquake weather". While not always the case, many major earthquakes have happened on incredibly beautiful days: bright blue skies, no clouds, calm winds, etc... That type of weather is coincident w/ high pressure and subsidence (sinking air). So some might argue that the higher pressure that the air is exerting onto the surface of the earth is another trigger mechanism to help start an earthquake.
Take it for what its worth. Just like the perigee and full/new moon examples above, these are not direct causes, just one of many possible triggers.