Astronomer Predicts Major Earthquake for Japan

[Ivan Seeking]

Originally posted by zoobyshoe
If you go to the little map in the story I linked to you can see that Hokkaido is a separate Island from Japan, and it is very far away from Tokyo, where he predicted the >7 quake. The epicenter is about as far from Tokyo as Vladivostok, Russia, and also as far away from Tokyo as parts of Korea. It is a totally different fault.
Think of it this way: if someone predicted a >7 quake for San Fransisco within a week, but it only got hit with a 5.5, and then a week later Portland got three, one of which was an 8, could we properly say the prediction was a hit? In my mind he was somewhere in a grey area between hit and miss which means, hopefully, that there is something to his methods that could be sharpened up to give more accurate results. He was quite certain Tokyo was in for it.
Knowing for certain that a specific city will be hit by a specific magnitude is the whole goal of trying to predict quakes.

It was about 600 miles from Tokyo. Vladivostok, Russia, is about 900 miles. However, we are using data from the entire Japanese area. Some of the quakes listed were centered 300 or 400 miles out at sea. One was near the location of the present quake. Also, the fact that Japan proper is so active, to me further supports the use of this data for comparison.

Finally, considering the magnitude, this may have been a subduction zone quake. In this situation, local faults may be of little significance. I don't know if a subduction zone quake is possible in this location. I will look.

Edit. It seems that one internet map used was not very accurate. The distances indicated are adjusted.

 

[zoobyshoe]

Originally posted by hypnagogue Hm... He predicted >= 7 for Tokyo, which only turned out to be a 5.5, but was followed up by an 8 in Hokkaido. Could it be that his model predicted the amount of energy churning about in the Earth's crust around Tokyo more accurately than the data bears out, but for some reason not all of that energy was dissipated in the Tokyo earthquake, and went on to contribute to the large magnitude of the event at Hokkaido?

I don't see any reason why this couldn't have been the case. If it were shown to be the case then it just points out the need for a lot of refinements in his methods, because it doesn't do much good for him to be off by a thousand miles for the people who get hit. If he is unable to get the location right then the fact he can predict within a thousand mile radius is a mere curiosity.

 

[Ivan Seeking]

Originally posted by hypnagogue
Hm... He predicted >= 7 for Tokyo, which only turned out to be a 5.5, but was followed up by an 8 in Hokkaido. Could it be that his model predicted the amount of energy churning about in the Earth's crust around Tokyo more accurately than the data bears out, but for some reason not all of that energy was dissipated in the Tokyo earthquake, and went on to contribute to the large magnitude of the event at Hokkaido?

This is similar to what I'm thinking. Also, we have no idea what his method is. Geographical range, timing, and magnitude are all variables that surely would result in different degrees of precision and accuracy in any foreseeable predictive model. To me, the crude but simple chance of success indicated is striking. I am at least 100% more interested than before. This means my left eyebrow is raised at least 0.250 inches now.

 

[hypnagogue]

zooby, I agree that his method, if it's really valid, could use some refining (if applicable-- maybe his method is just an inherently crude measure). But assuming it wasn't a fluke, even a crude estimate of a high magnitude earthquake like this would be valuable, certainly better than nothing. So in the future, to be more accurate he might have to warn not just Tokyo but all of Japan-- there's obvious practical problems with this, eg Japan residents wouldn't know of a safe place within Japan to hide out for a while, and most areas would suffer from anxiety and the cost of preparations for nothing. But preparations made in those areas that actually are struck could still ultimately save lives-- there could still be actual practical benefits.

 

[Ivan Seeking]

Some related info showing the location of the Japanese subduction zones:
http://atlas.geo.cornell.edu/education/instructor/topography/japan.html

http://geology.about.com/library/bl/maps/bljapanseismap.htm

It seems that this could be a major subduction zone event; we will have to wait and see. If so, it would seem possible that certain predictive indicators might have to be viewed in a broader geographical context than was indicated.

 

[kleinma]

perhaps the first quake he predicted was accurate, and the following quake was a result of the initial one...

regardless, they should look into his methods and see about possibly improving on them, because his ways for detecting quakes obviously shows he is doing something right.

I think the fact that his predictions were not 100% accurate is minor compared to the fact that he obviously has something going on for himself

 

[Ivan Seeking]

Originally posted by hypnagogue

By the way hypnagogue, thanks much for your kind words and your vote.

 

[hypnagogue]

No problem my man, you earned it. A board like this absolutely needs a solid and composed voice for open-mindedness, otherwise it just stagnates into arguments of dogma.

 

[hypnagogue]

Plus, the articles you post are thought provoking and sometimes provide a member with a pretty new avatar.

 

[Ivan Seeking]

The man who predicted last week's quake has gained sudden credibility, writes Shane Green in Tokyo.

http://www.theage.com.au/articles/2003/09/26/1064083188094.html

Well, maybe...

 

[Ivan Seeking]

Magnitude 8.3 HOKKAIDO, JAPAN REGION
2003 September 25 19:50:06 UTC
Preliminary Earthquake Report
U.S. Geological Survey, National Earthquake Information Center
World Data Center for Seismology, Denver



Magnitude 8.3
Date-Time Thursday, September 25, 2003 at 19:50:06 (UTC) - Coordinated Universal Time
Friday, September 26, 2003 at 04:50:06 AM local time at epicenter
Time of Earthquake in other Time Zones
Location 41.83N 143.83E
Depth 33.0 kilometers
Region HOKKAIDO, JAPAN REGION
Reference 135 km (85 miles) SSW of Kushiro, Hokkaido, Japan
245 km (150 miles) NE of Hachinohe, Honshu, Japan
245 km (155 miles) SSE of Asahikawa, Hokkaido, Japan
770 km (480 miles) NNE of TOKYO, Japan

Location Quality Error estimate: horizontal +/- 5.7 km; depth fixed by location program
Location Quality
Parameters Nst=199, Nph=199, Dmin=575.6 km, Rmss=0.84 sec, Erho=5.7 km, Erzz=0 km, Gp=34.2 degrees
Source USGS NEIC (WDCS-D)
Remarks At least 400 people injured, extensive damage, landslides and power outages occurred and many roads damaged in southeastern Hokkaido. A tsunami generated with an estimated wave height of 1.0 meter along the southeastern coast of Hokkaido. Felt strongly in much of Hokkaido. Also felt in northern and much of central Honshu as far south as Tokyo. Recorded (6L JMA) in southern Hokkaido; (5U JMA) in parts of eastern Hokkaido; (5L JMA) in central Hokkaido; (4JMA) in parts of Hokkaido and northern Honshu; (3 JMA) in southern Iwate, Akita, Miyagi, Yamagata and northern Fukushima; (2 JMA) in southern Fukushima, northern Niigata, eastern Tochigi, Ibaraki, Saitama, Tokyo, Chiba, Kanagawa, eastern Shizuoka and eastern Yamanashi; (1 JMA) in eastern Gumma and parts of Nagano Prefectures. Also recorded (1 JMA) on Miyake-jima and Hachijo-jima.


Tectonic Summary
The preliminary location and focal-mechanism of this earthquake imply that it occurred as the result of thrust-faulting on the plate interface between the overriding North American plate (which extends into the northeast corner of the Eurasian landmass) and the subducting Pacific plate. The Pacific plate is moving west-northwest at a rate of about 8.2 cm per year relative to the North American plate. In addition to experiencing great thrust earthquakes that originate on the interface between the plates, eastern Hokkaido experiences great earthquakes that originate from the interior of subducted Pacific plate. The earthquakes of March 4, 1952, and May 16, 1968 (cited below) were interface-thrust earthquakes, whereas the earthquake of January 15, 1993 (cited below) occurred within the interior of the subducted Pacific plate. The recent earthquake appears to have involved rupture of the same section of the plate interface that ruptured in 1952.

Magnitude 8 and greater earthquakes are capable of devastating large areas. The shallow September 25 Hokkaido earthquake occurred about 60 km offshore. If the earthquake had occurred directly beneath a populated region, damage would have been more severe.

Previous Deadly Earthquakes in this Region
Date UTC Magnitude Fatalities Damage
1952 March 4 8.6 31 31 killed, 72 injured; 713 houses destroyed, 5,980 damaged. 28 killed and warehouses destroyed at Kushiro. 3 killed and 309 houses destroyed at Kiratapu. 1,000 houses destroyed or damaged at Shiranuka and 400 schools collapsed at Sapporo. 10-foot tsunami.
1968 May 16 7.9 48 Damage estimate at 25 million USD.
1993 January 15 7.6 2 614 injured and substantial damage (VI JMA) at Kushiro, Hokkaido and Hachinohe, Honshu. Felt (V JMA) at Hiroo, Nemuro, Obihiro, Otaru and Urakawa; (IV JMA) at Hakodate and Tomakomai; (III JMA) at Sapporo, Hokkaido. Felt (IV JMA) at Aomori and Morioka; (III JMA) at Akita, Fukushima, Sendai, Tokyo and Yokohama, Honshu. Also felt (VII) on Shikotan and (VI) at Kurilsk, Kuril Islands. Landslides and subsidence occurred in the epicentral area.

The last great earthquake (magnitude 8 or greater) in the world was a magnitude 8.4 that occurred on June 23, 2001, near the coast of Peru. This earthquake killed at least 75, including 26 killed by the associated tsunami.

http://neic.usgs.gov/neis/bulletin/neic_zdap.html

 

[Ivan Seeking]

The preliminary location and focal-mechanism of this earthquake imply that it occurred as the result of thrust-faulting on the plate interface between the overriding North American plate (which extends into the northeast corner of the Eurasian landmass) and the subducting Pacific plate.

Since this appears to be a subduction zone event, it would seem reasonable that local faults played little to no role in this quake. I tend to think this guy might be on to something.

 

[Nereid]

Aren't we missing at least two rather important considerations?

1) Did this guy make public, ahead of time, ALL his predictions? If so, we can assess his track record, by making sure we match (or not) his predictions against actual earthquakes, and vice versa. If not, then the Nereid earthquake prediction method* is far superior.

2) How many other people have been making predictions of Japanese earthquakes? Where are their predictions? In the population of Japanese earthquake predictions, what are the chances of one of them coming as close as this?

*I have a computer program which randomly generates a magnitude-time-location. I print two copies, put one in an envelope, seal it, and write today's date on the envelope together with the other copy stuck on with stickytape. I repeat. My filing cabinet is overflowing, but every time there is an earthquake, I can assure you that I can produce an unopened envelope with a prediction that is close to what just happened!

 

[Ivan Seeking]

Originally posted by Nereid
Aren't we missing at least two rather important considerations?

1) Did this guy make public, ahead of time, ALL his predictions? If so, we can assess his track record, by making sure we match (or not) his predictions against actual earthquakes, and vice versa. If not, then the Nereid earthquake prediction method* is far superior.

2) How many other people have been making predictions of Japanese earthquakes? Where are their predictions? In the population of Japanese earthquake predictions, what are the chances of one of them coming as close as this?

*I have a computer program which randomly generates a magnitude-time-location. I print two copies, put one in an envelope, seal it, and write today's date on the envelope together with the other copy stuck on with stickytape. I repeat. My filing cabinet is overflowing, but every time there is an earthquake, I can assure you that I can produce an unopened envelope with a prediction that is close to what just happened!

Go to the first post in this thread.

 

[Ivan Seeking]

Originally posted by Nereid
2) How many other people have been making predictions of Japanese earthquakes? Where are their predictions? In the population of Japanese earthquake predictions, what are the chances of one of them coming as close as this?

~1:600. One potential difference between this claim and others is that he claims to be using methods that can be subjected to scientific scrutiny. Also, since quakes >= mag 7 are rare, we don't find many predictions of quakes this size since you will most likely be wrong. Still, If I predict a mag 7 or greater anywhere in the world within 1 week, I have about a 40% chance of being right. To predict a quake in one particular place like Japan narrows the odds quite a bit. Of course, my chances of correctly randomly predicting a quake in the central US are much worse than getting one correct, just by chance, in California for example. But, the odds for a large quake were estimated using the history of quakes in Japan.

 

[Ivan Seeking]

Please continue this discussion in the geology forum. To me, it seems that a critique of his methods is purely a scientific matter. If we should find a [scientific] credibility problem with this amateur astronomer, I will reopen this thread. This is not meant to imply that this quake was anything other than coincidental.

https://www.physicsforums.com/showthread.php?s=&postid=74904#post74904