- 13 Jan 2005
- 145
- 5
Was the earthquake that hit Japan a few days ago the 'big one' that geologists have been expecting? I know the last 'big one' happened back in 1923. 1923 Great Kantō earthquake - Wikipedia
Was that quake the 'big one'?
- Thread starter Mahoujin Tsukai
- Start date
- 21 May 2003
- 14,310
- 4,404
We have to wait............
for the DNA , toxicology , and fingerprint results to come back from the lab to be sure. I bet the people who suffered through it felt it was the "BIG" one.
Uncle Frank
Sorry I could not resist. It will probably take scientists a while to meet and agree on the results of this quake and compare it to others.
for the DNA , toxicology , and fingerprint results to come back from the lab to be sure. I bet the people who suffered through it felt it was the "BIG" one.
Uncle Frank
Sorry I could not resist. It will probably take scientists a while to meet and agree on the results of this quake and compare it to others.
Jericho Desu
七転八起
- 23 Feb 2008
- 1,105
- 28
Don't know what counts as "the big one", but it was the largest earthquake in Japanese history and the 5th largest in world history, I'd say that was plenty big
- 15 Mar 2002
- 16,758
- 2,298
The largest measured earthquake in the history of Japanese earthquakes. Japanese earthquake measuring history goes back 140 years. Japanese history goes back some little bit beyond that.
Jericho Desu
七転八起
- 23 Feb 2008
- 1,105
- 28
Chidoriashi
In imagination land
- 2 Feb 2007
- 824
- 63
The "big one" they have been talking about for the past 60 years is the Tokai Earthquake, and I am pretty sure it is unrelated to the quake on Friday. The Tokai Earthquake is expected to have the greatest impact on Tokyo and Shizuoka and potentially kill 30,000 people, and I really hope it holds off for many more years. Tōkai earthquakes - Wikipedia
EmperorHirohito
Who is Number One?
- 30 Apr 2007
- 1,548
- 40
The fact that there are still powerfull aftershocks being felt, I do wonder if another quake will happen soon. Japan is bordered by 3 plates joining, the Pacific, Eurasian and Phillipines. Both myself and my wife just hope there is not movement at the point of where all three plates meet, it is southeast of Tokyo.
Nuala
Hell's Finest Daughter
- 15 Jul 2004
- 1,725
- 39
Let's pray that does not occur. No, I'm not thinking about that. The likelihood isn't that out there, but can any of us imagine? It's too much already.
- 5 Feb 2005
- 7,694
- 627
"As Japan scrambles to pick up the pieces from Friday's magnitude-9 earthquake and tsunami, the Kyodo news agency is reporting that there is a 70% chance of a magnitude-7 or greater quake taking place in the next three days.
Kyodo also reports that there is a 50% chance of one hitting in the three days after that...
Read the whole article here:
http://newsonjapan.com/html/newsdesk/article/87974.php "
EmperorHirohito
Who is Number One?
- 30 Apr 2007
- 1,548
- 40
I hope it doesnt happen, and pray it doesnt. But I was out in California many years ago when San Francisco got hit again, and that was scary. Please Mother Nature calm down for a bit please.
Nuala
Hell's Finest Daughter
- 15 Jul 2004
- 1,725
- 39
I think everyone is hoping and praying with you, EmperorHirohito. Try to stay strong.
Chidoriashi
In imagination land
- 2 Feb 2007
- 824
- 63
What they forget to mention though is there is also a 70% they have no idea what they are talking about.
They had been talking about the tokai quake for 60 years, but zero prediction was given about the one on Friday..
- 11 Mar 2011
- 33
- 0
ﾂ坂?壺?堋｢ﾅｽRﾂ、ﾂ深窶堋｢窶價.ﾂ債｡窶扼窶堙坂?堙??堙俄?堋ｩ窶堋ｭ窶ｹﾃ俄?兌窶堙遺?ｰﾃ芝ｽRﾅ?ﾋ??慊ｮ窶堙娯?扼窶堙??堋ｷ
Colin Howell
先輩
- 18 Oct 2009
- 30
- 6
Sorry, you're off-base here. In part that's due to the media distorting the prediction that was originally made.
The prediction of "70% chance of a mag-7 or greater quake in the next 3 days, and 50% chance of one in the 3 days after that" came from the Japan Meteorological Agency in its first English report on the Sendai quake, issued on 13 March, and was only a statement about aftershocks of that quake: "Estimating from the occurrence of aftershock so far, the possibility of aftershocks with magnitude of 7 or higher is 70% until 10 a.m., 16 March, followed by 50% until 10 a.m., 19 March."
This seems to be a perfectly reasonable prediction; after a huge event like that, you would expect large aftershocks for a while as the affected portions of the crustal plates settled down. However, according to the USGS the last mag-7+ aftershock was on 11 March just after the initial quake, and JMA has refrained from making such specific predicitions of aftershock magnitude in their later reports, only discussing local shaking intensity. So maybe they decided they overstated things.
It's no surprise that they failed to predict Friday's quake, since it looks like it was the sort of event which only occurs every thousand years or so, with the last similar event occuring in A.D. 869. The approximate size of that previous quake was only realized in the last decade, due to studies of tsunami sediment deposits. Those studies also showed two previous similar events in the last 3000 years, but with only very rough dating. As it happened, there was a paper published in 2007 in which geologists from the Geological Survey of Japan predicted a 99% chance for another similar quake in the region within the next 30 years. But with such a long interval and rough dating, precise prediction becomes very difficult, and it would be understandable if the JMA held back from making any specific predictions there.
And as for the predicted Tokai quake (the so-called "big one" everyone talks about, though it would likely have a lot less seismic energy than the Sendai quake), it occupied everyone's attention for obvious reasons: the affected region has a much greater population, the records are better, and the period is much shorter, giving a much better basis for a prediction. It still remains a hazard. The Sendai quake simply beat the predicted Tokai quake to the punch; saying the JMA doesn't know what they're talking about based on that seems quite unfair to them.
Completely wrong. big Miyagi quakes are known to happen every 20 or 30 years. The last one happened 33 years ago, I think. This time, I was there, spent 4 nights at an evacuation camp until last night. The first thing people were talking about, about 2 hours after the quake, was "hey do you think this is the big Miyagi earthquake we've been expecting?"
- 13 Jan 2005
- 145
- 5
- Thread starter
- #16
Thanks for the replies!
Chidoriashi
In imagination land
- 2 Feb 2007
- 824
- 63
More or less I was just trying to point out that there is a lot of futility in trying to predict earthquakes with our current knowledge and technology. In any case it has been a week.. and.. surprise.. they were wrong. .. i guess I should say.. they were 70% wrong.
Chidoriashi
In imagination land
- 2 Feb 2007
- 824
- 63
Big quakes every 20 or 30 years? I hope you are not implying quakes like the one last Friday? Anyhow I would like you to show me some data about these big ones every 20-30 years from what I can find there was one in 1978.. and nothing fits the pattern you are talking about after that.
Do these quakes have a formal name btw?
Colin Howell
先輩
- 18 Oct 2009
- 30
- 6
True enough. About the best you can do in most cases is to give a general statements about the chances of a particular fault generating a large quake--assuming you have enough data on the fault's history to make a useful prediction. It's not like predicting hurricanes. :?
Full disclosure: in a previous career I studied geology, and one of the professors I worked for (Kerry Sieh) specialized in predictions of earthquake hazards based on studies of the geological traces of past earthquake events.
undrentide
Japa'n vagyok
- 18 Jan 2006
- 3,652
- 310
They are called 窶ｹ{ﾂ湘ｩ窶ｰﾂｫ窶冢ﾂ震. (Miyagi-oki-jishin/Miyagi Offshore Earthquake)
Date since the previous one magnitude
17th Feb. 1793 ---- M8.2
20th July 1835 42.4 years M7.3
21st Oct. 1861 26.3 years M7.4
20th Feb. 1897 35.3 years M7.4
3rd Nov. 1936 39.7 years M7.4
12th June 1978 41.6 years M7.4
(average 37.1 years)
2005 Miyagi earthquake - Wikipedia
*English version does not have the above details but direct link to Japanese page does not work in this forum. Click the above and then go to 窶愿ｺ窶怒ﾅ津ｪ.
Also I do not know why the one in 2005 is linked to 窶ｹ{ﾂ湘ｩ窶ｰﾂｫ窶冢ﾂ震ﾂ、 as 2005 Miyagi earthquake is the one NOT recognized as one of 窶ｹ{ﾂ湘ｩ窶ｰﾂｫ窶冢ﾂ震 which occurs at a certain interval of 30 years or so.
Scalemx
先輩
- 27 Oct 2009
- 64
- 0
I am very sad to inform you that this is not the three plate earthquake that everyone had been expecting. The facts on the big earthquake, which is expected to have an epicenter East of Japan, think somewhere of the coast between Yokohama and Southern Shikoku .
The expected magnitude: 8
The expected probability: 50% in the next 30 years
This information I got from a lecture from a professor specialized in Seismic activity at my Japanese university.
If you have an apartment along the Tokaido shinkansen line, think twice and if you live in the area, be better safe than sorry.
The expected magnitude: 8
The expected probability: 50% in the next 30 years
This information I got from a lecture from a professor specialized in Seismic activity at my Japanese university.
If you have an apartment along the Tokaido shinkansen line, think twice and if you live in the area, be better safe than sorry.
undrentide
Japa'n vagyok
- 18 Jan 2006
- 3,652
- 310
The Tohoku earthquake was so big, it "stimulated" other plates and faults.
The North America plate moved about 50 meters towards the Pacific Ocean and upthrust about 7 meters because of the quake, Japan islands are pulled towards the Pacific Ocean, max. 5.3m (Oshika peninsula).
*Map showing the move of the benchmarks by GEONET - GPS Earth Observation Network System.
http://www.gsi.go.jp/common/000059672.pdf
We have many earthquakes not related to the North America plate recently, some of them are a kind of reflexes, trying to modify the distortion and rectify the imbalance, according to the specialists (got this info on the TV.)
That means Japan is more active than before, in terms of earthquakes.
Possibility that we may have another big earthquake of the scale more than M7.0 in the near future is rather high, though no one can tell exactly when.
The North America plate moved about 50 meters towards the Pacific Ocean and upthrust about 7 meters because of the quake, Japan islands are pulled towards the Pacific Ocean, max. 5.3m (Oshika peninsula).
*Map showing the move of the benchmarks by GEONET - GPS Earth Observation Network System.
http://www.gsi.go.jp/common/000059672.pdf
We have many earthquakes not related to the North America plate recently, some of them are a kind of reflexes, trying to modify the distortion and rectify the imbalance, according to the specialists (got this info on the TV.)
That means Japan is more active than before, in terms of earthquakes.
Possibility that we may have another big earthquake of the scale more than M7.0 in the near future is rather high, though no one can tell exactly when.
Jericho Desu
七転八起
- 23 Feb 2008
- 1,105
- 28
Thats terrible news, does the higher rate of earthquakes apply to all parts of Japan?
undrentide
Japa'n vagyok
- 18 Jan 2006
- 3,652
- 310
Generally yes, I believe.
Yesterday we had a small one (M4.1, max. seismic intensity scale 3) whose epicenter is Kiisuidou, Wakayama where the earthquake is rare.
http://weather.asahi.com/quake/top110507215720.html
"Higher rate" is very vague, it's a comparison to the past and we can say it either for 1% increase or 100% increase.
I do not know how much higher, I'll post again on this if I find any additional information.
