Astronomer Predicts Major Earthquake for Japan

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A Japanese researcher predicted a major earthquake of magnitude 7.0 or greater for Tokyo, which did not occur as expected, with only a 5.5 magnitude quake happening shortly before the prediction. The energy released was significantly lower than anticipated, raising questions about the accuracy of the prediction methods. Discussions highlighted the inherent risks in predicting earthquakes, likening it to flipping a coin. A week later, however, three powerful earthquakes struck Hokkaido, including one estimated at 8.0, leading to injuries and tsunami warnings. The conversation reflects skepticism about earthquake prediction accuracy, emphasizing the need for more reliable forecasting methods.
  • #61
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
 
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  • #62
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.
 
  • #63
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!
 
  • #64
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.
 
  • #65
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.
 
  • #66
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
 

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