Earthquake and Tsunami Prediction

If I can take off my Mars explorer hat for a moment and put on my seismologist hat, I'd like to clear up something with everyone. We can't predict earthquakes or tsunamis. It's not currently scientifically possible to say when an earthquake or tsunami will happen. Based on probabilistic analysis, we can guess where they are likely to happen, but constraining when is not (yet) possible.

Why do I bring this up? Because for the past two months there has been a rumor circulating on the internet that a tsunami will happen on July 22. The basic premise behind the claim is that the combined gravitational pull of the Sun and Moon pulling on the Earth's tectonic plates during the July 22 lunar eclipse will cause a major quake. The author of the tsunami hoax (as it's being called) took some NASA data of the eclipse path across the Pacific and compared where it crossed tectonic plate margins. Based on when the maximum eclipse would pass over the area (and factoring in an arbitrary 1 hour lag time), the person assumed an underwater earthquake would be triggered and therefore a tsunami too.

While researchers have and continue to investigate any (weak, if any) relationship earthquakes have with the tides, the scientific consensus is that great earthquakes cannot be triggered by the very weak tidal forces imposed on them, even when these forces are at their maximum during eclipses. (Tiny earthquakes may sometimes correlate with the tides, but those are never dangerous and certainly not tsunamigenic.) The July 22 prediction is simply speculation and is NOT based on science. This type of hoax preys upon people's fears and spreads unnecessary and perhaps even dangerous false alarm.



I can't tell you how many emails I've fielded from concerned people asking about this - probably about one per day on average for two months. In all cases, I've told the emailer that the rumor cannot be true, and there is no way to determine when the next quake will strike. All we can do is act quickly and appropriately once it does. This hoax has gotten so prevalent that NOAA even released a short statement today:

NOAA's Tsunami Warning Centers in Hawaii and Alaska operate 24 hours a day monitoring seismic and water level data for potential tsunamis. According to the scientists on duty, none of the predictions about July 22 should be taken seriously. There is no correlation between
 earthquakes and eclipses and there is no scientific reason for a big earthquake or a tsunami to occur preferentially in July.

However, anyone living near the coast should learn as much as tsunamis as possible and be prepared. In particular, you should know the natural warning signs and take action to go inland to a higher elevation if you are near the beach and the following occurs: (1) you feel an earthquake -- the ground starts shaking and it is hard to stand up, (2) the water recedes from the shoreline exposing the ocean floor, and (3) you hear a loud roar coming from the ocean. For additional information please visit the following websites: International Tsunami Information Center, Snopes.


The Snopes site does a pretty good job at refuting the claims made in the supposed tsunami prediction. Also, remember that tsunamis aren't weather either!

July 10 Update: Check out the Earth Observatory of Singapore for a really good debunking of this hoax.

July 20 Update: The hysteria has gotten so bad in Sri Lanka, that their Meteorology Department issued a statement earlier today denying any truth to the hoax.
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9 comments:

Anonymous said...

There is another warning for the July 22nd 2009 solar eclipse causing earthquakes in China. This one is made by a known scientist with a background in physics. What do you make of this?

http://www.rqm.ch/earthquake_warnings_with_magnitu1.htm

brian said...

Thanks for pointing out the Chinese link. I find it highly suspect. They don't cite any scientific publications supporting their claim, and I know that almost no seismologist in the western world would give much credence to this theory. This sentence in particular raises red flags:

"The new principles of space quantum physics automatically lead to a revised gravitation theory as postulated by Oliver Crane, identifying a cosmic mechanical down-pressure instead of the gravity or mass attraction taught in traditional physics."

Huh? How could "space quantum physics" have anything to do with the macro-movement of tectonic faults? They also claim that the "centrifugal force pushes the earth’s crust outward." Well, sure there is a centrifugal force due to the earth's rotation, but its effect on the crust is negligible. Besides, the earth always rotates. This isn't anything unusual. The alignment due to the eclipse will produce extra gravitational forces so minor that it won't cause major fault slippage.

They also say that a supernova and " cosmic and planetary constellations" can trigger earthquakes. This makes no sense at all. I'm forced to conclude this theory falls squarely in the same realm as astrology. It's not science.

Either this page is a hoax, or the Chinese Institute for Space Quantum Physics needs to do some serious work on explaining itself.

Anonymous said...

http://www.earthobservatory.sg/news/2009/20090415-july22-Tsunami-Hoax/index.php

What are the odds of correctly predicting an earthquake and tsunami?

Anonymous said...

http://www.earthobservatory.sg/news/2009/20090415-July22-Tsunami-Hoax/index.php

sorry... correct link above

brian said...

It's not meaningful to say there are any odds for predicting earthquakes or tsunamis since there is no scientific way at present to do so. For earthquakes, the best we can do is say that there is a certain percent probability of a earthquake of a given size on a specific fault in the next given number of years. For example, in California, the probability of a magnitude 6.7 or larger earthquake over the next 30 years striking the greater Los Angeles area is 67%, and in the San Francisco Bay Area it is 63%.

Anonymous said...

Here is a 2001 paper published in Tawain indicating a relationship between the lunar tides and earthquakes. Is this valid?

http://www.springerlink.com/content/y8r15x9n9qrn8upq/

brian said...

Thanks for sharing that paper. I haven't read it, but I will try to look at it the first chance I get. Since I'm away on an expedition now, if someone could email me the paper, I could read if while I'm here.

As someone interested in both the solid earth and orbital mechanics, I will probably find the paper very interesting. My guess is that it relies heavily upon statistics to look back in the historical record to find a correlation between the tides and seismicity. The real prize is predicting future events with some degree of reliability, and I'm pretty sure these guys can't do that because if they could we'd be successfully predicting earthquakes all of the time.

Anonymous said...

If we could do research that correlates earthquakes to tides, then you are right we should be able to predict them all the time.

But your logic seem a bit flawed... Isn't that what they are doing with this eclipse? Making a precition based on historical correlations?

brian said...

We'll find out in two days!