# Astronomer Predicts Major Earthquake for Japan

1. Sep 18, 2003

### Ivan Seeking

Staff Emeritus
This will either debunk itself in a week, or we move this prediction to another forum.

http://www.space.com/scienceastronomy/quake_prediction_030915.html

Edit: A summary of this thread:

A quake with a magnitude >= 7.0 was predicted for Tokyo for Tuesday or Wednesday. In fact, Tokyo experienced a magnitude 5.5 quake on Saturday.

The energy was about 99.5% less than expected.

The Richter value was in error by 21%

I would think that the odds of a 5.5 quake on any day is no worse than 1:3500. So, if we were off by three days, we might allow for odds like 1:1000 of getting this close by chance. Of course this is just for perspective and not meant as hard numbers. The real number may well be more like 1:100.

I didn’t find a good number for the frequency of Japanese quakes, but I did find a couple of interesting, related sites.

http://neic.usgs.gov/neis/current/japan.html

http://www.owlnet.rice.edu/~geol108/eq4/site_directory.htm#Earthquakes

It is not clear, but the key measure apparently [according to this news report] is measured in reference to the Richter Scale value and not in terms of energy. It seems that an arugment might be made that with no better than 1:100 chance of random success, this quake was predicted within 21% of the actual magnitude. It is also possible that the result [if we use energy as the indicator] was in fact only 0.5% of the expected value.

Edit #2: Then, a week later...
TOKYO, Sept. 26 — Three powerful earthquakes, one of them of potentially historic magnitude [estimated as being an 8.0], struck Hokkaido in northern Japan early Friday morning, causing major structural damage, NBC News reported. The quakes injured more than 240 people and generated a 7-foot-high tsunami off the coast of Hokkaido. Tsunami advisories were issued for much of the Pacific region, including Japan, Russia and the Philippines.
http://www.msnbc.com/news/971921.asp?pne=msntv

This event appears to yield odds of random success - of predicting any quake >=7.0, anywhere in Japan within one week - of around 1:600.

Last edited: Sep 26, 2003
2. Sep 18, 2003

### zoobyshoe

Predicting a major earthquake for
Japan is about as risky as
flipping a coin: "Well, I wasn't
`major' part but the was
an earthquake!"

3. Sep 20, 2003

### Ivan Seeking

Staff Emeritus
I agree. Still, if this guy had hit the day and magnitude with a high degree of accuracy - say within 12 hours and within 30% magnitude - then he might as least bare watching, but otherwise it really wouldn't mean much. I heard a report of a 5.5 in Tokyo today. I have not seen this reported elsewhere yet.

Here is another recent event to help put this into perspective:
http://news.bbc.co.uk/2/hi/asia-pacific/2938248.stm

It would take more than even one very accurate hit to really get peoples attention.

4. Sep 20, 2003

### zoobyshoe

Tsunami,

5. Sep 20, 2003

### Tsu

Yes, I know. I can never get this @#%^&!@#$#%^%$$^^&&^$$%$ thing to work right. I've done it twice and deleted my post twice. It's making me BANANAS!!!!!!!!!!

6. Sep 20, 2003

### Tsu

Last edited: Sep 20, 2003
7. Sep 20, 2003

### Tsu

So, would a 5.5 magnitude earthquake AND a typhoon hitting at the same time be fairly equivalent of a 7 magnitude earthquake?

8. Sep 20, 2003

### zoobyshoe

He predicted 7 or greater. The
quake was 5.5. I guess he can quote me, if he wants.

9. Sep 20, 2003

### Tsu

We posted at exactly the same time. You missed my "quetion"!

10. Sep 20, 2003

### Ivan Seeking

Staff Emeritus
Since we did in fact see a quake withing 2 days and 25% of the prediction, my left eyebrow gets raised exactly 0.125". I'm going to take a little closer look.

11. Sep 20, 2003

### Tsu

Mine raised APPROXIMATELY 0.25" (I'm well practiced in eyebrow raising) - I didn't take an EXACT measurement like Ivan obviously did. Ivan - you're a little STRANGE! But then, I do like strange...

Personally, I'm going to give it a 7 since it was REALLY a double-whammy. Let's give that scientist a round of applause and add a Flying Fickle Finger of Fate award (anyone remember those?)!

12. Sep 20, 2003

### zoobyshoe

Would this be millimeters or
thousandths?

13. Sep 20, 2003

### Ivan Seeking

Staff Emeritus
Keep it up and I'll turn your fish into a guppy.

14. Sep 20, 2003

### Ivan Seeking

Staff Emeritus
that was 0.125" as in inches. Obviously I'm feeling more generous than you.

Also, a close look reveals that I don't have eyebrows.

Primitives...hah!

Last edited: Sep 20, 2003
15. Sep 20, 2003

### Tsu

Yeah. I'm shakin' in my fins.

16. Sep 20, 2003

### Ivan Seeking

Staff Emeritus

Not bad Tsunami! I rate that as a seven head funny. No wonder you're up for chief comedian.

17. Sep 20, 2003

### zoobyshoe

I am actually impressed that he
got the time and location right.
I was expecting there would be the
usual 4.0 somewhere in
Japan and that he'd try to take
credit for having forseen it. It
could be his system works accur-
ately, except when there's
a typhoon on the way.

18. Sep 20, 2003

### Tsu

I am nowhere NEAR being a physicist (didn't even LIKE it in school - sorry guys, but there are LOTS of us in the world! ) but, would it be possible that the presence of the typhoon kept the magnitude down to a 5.5 instead of the predicted 7?

19. Sep 20, 2003

### Ivan Seeking

Staff Emeritus
Whoops. I made a giant mistake in the error. I treated the magnitude of the quake as a simple linear scale. As I recall from my geophysics class, in reality, the difference in the actual energy of a 5.5 and a 7.0 is about 6 or 7 times the energy. So really our margin of error is probably about 600-700%.

20. Sep 20, 2003

### zoobyshoe

alot of water around. There is
some remote chance this shift in
weight would affect the shifting
of the tectonic plates.

Likewise the typhoon would change
the barometric pressure consid-
erably which, because it would
be affecting such a huge area,
might also have some effect on
the plates.

Thats as far as I can stretch to
come up with possible ways it
could have modified the earth-
quake.