The Final Warning to Tokyo

reply to post by TrueAmerican


No Quake or Tremor here, until now 18.05 JST.

Originally posted by Human0815
reply to post by TrueAmerican

 

No Quake or Tremor here, until now 18.05 JST.

Well, that far out at sea you may not have felt that quake at all in Tokyo, and besides I believe it will be downgraded to a 4.9 or so after seeing the phase data and waveform. It just wasn't that strong. But according to the USGS, it happened. Could be a mistake. Time will tell.

reply to post by TrueAmerican


My EQ-Info Device (Yurekuru) have no info listed and they send normally
every Tremor!

But many Quakes on the American Quake Center get removed after a check up!

reply to post by TrueAmerican

Hi TA,

I hate to say it but I am more concerned about the situation in that region now than I was months ago. Just my feeling and with no scientific justification at all. I sincerely hope that they do not get a massive quake any time soon, because wintry conditions would make it far more difficult for homeless survivors than in warmer weather.

In the past I did quite a bit of reading online about the 1923 quake, and while there is plenty of information about the main event itself and the aftershocks, there seems to be very little about any foreshocks. In fact, I have not found any specific references to any, suggesting that if they occurred they were either a fair way out to sea or not very powerful -- a somewhat different situation to the March 11 Japan quake, where (as you know) there was a strong foreshock in the mag 7 range only 2 days prior to the mainshock.

From a scientific/historical standpoint, back in 1972 in an article in Tectonophysics, Suyehiro and Sekiya stated:

Very large earthquakes can also take place without any immediate foreshocks. The great Kanto earthquake of 1923 was not preceded by any immediate foreshocks. However, the seismic activity in the general region became abnormally high from one year prior to the earthquake.

Source: an abstract from Science Direct (dot) com

Unfortunately, due to the massive March 11 quake on a different but related subduction zone futher up Honshu's east coast and its own subsequent aftershocks, I'd suppose it is hard to define if the quakes in the region under discussion can all be considered as aftershocks of that event, or if they are possibly foreshocks of another megathrust quake. My own feeling is that while they could well be a mixture of both, the quakes on or near the boundary you've indicated (and especially near the triple junction) might well indicate the latter.

It's pretty much a given in both the Japanese scientific community and among the general population that there will be another huge quake in that region one day, but again, my hope is that it doesn't come in the colder months.

Mike

you cant and you should not hide from your destiny,
instead you need to live your life in every moment!

there will be a big quake coming soon
and as far as i can see (my horizon is very limited)
the preparations are running high (or hot?)

03/11 was in the winter and many people do not went/ run
into the tsunami evacuation centers because when
they have been there are few day before the big one
they felt cold, it is a irony of that kind which is so
typical for the human life!

reply to post by JustMike

However, the seismic activity in the general region became abnormally high from one year prior to the earthquake.

Yeah well the problem is how do you even gauge the level of seismicity at this point in the area after a quake that big? It is affecting everything. So the symptoms of increased seismicity may all add up to nothing, or they could be foreshocks to a big quake near the triple junctions (TJ). Either TJ. Both have shown response to the 9.1, and in a way that's a good sign, if that's all it's got for now.

And let's not forget the 6+ they had on the leftside TJ, not long after the 9.1. Or it's possible the same area of the 1923 could go again, but not likely, unless new stress occurred after the 9.1. But the stress was relieved in 1923, so I am thinking if another big one occurred, it would probably be near the right TJ.

But hopefully the best case scenario is happening, and it will adjust slowly in small increments. Or in as small increments as can be, considering the size of the zone. So far though it has stood up admirably to the most intense seismic barrage recorded on the planet. In that, perhaps, the Japanese people can take some comfort. The southern SZ (so far) appears to be a very stubborn mule capable of withstanding shock after shock without giving way- in a big way. But even that stubborn a mule may wear down through seismic attrition of sorts, and rupture- so I wouldn't let down the guard just yet.

Overall I would describe the current situation with the SSZ as "delicate, and on a hair trigger alert".

reply to post by TrueAmerican

Yes, it definitely makes sense that a different section from the previous major quake is more likely to let go. At least, that has tended to be what has been observed elsewhere and for good reasons of simple physics if nothing else. I'd also agree that there having been such a huge quake in the general region, it's almost impossible to determine what level of activity is normal around the TJ/s.

I've long felt that while smaller quakes do help to relieve some of the stress they probably don't have a major effect on the total energy released when a "big one" finally happens. True, they are better than nothing, but considering that the long-term energy buildup exceeds the releases by smaller quakes (otherwise big ones would never happen) as the energy input is more-or-less ongoing, they alone will not be enough to defray the eventual arrival of a big one. I appreciate that you are in no way implying that they do, but just clarifying my response. I tend to feel that the smaller quakes are perhaps beneficial in that they increase the time periods between the larger ones, and that could in some cases amount to a considerable amount of time if looked at in mere human terms.

A final note before I rush back to work: TA, I and I'm sure many others appreciate the thought and effort you put into threads like this one, what with the references, maps and other data as well as your own analysis. But more than that, it's good to see you call it as you see it.

Mike

During the past few days there have been 5 moderate sized quakes in Tokyo's vicinity.
Source
I sure hope these Mag 5's are releasing stress, and not foreshadowing things to come. Be safe residents of Japan.

reply to post by Olivine


What I expected many months ago is taking a lot longer, but it is happening nonetheless. Tokyo area seems to be getting more quakes, and now the area near the triple junction is starting to express its discontent:



earthquake.usgs.gov...

It is interesting they are happening so far more on the Pacific Plate side. But lookout.

Oh fearmonger me.

Hmm, so this 7.0 is just a random coincidence right?



earthquake.usgs.gov...

Or is it reaction on the south from activity in the north?

I just read this news article found on the PNSN.org website. It basically confirms everything you have been saying, TrueAmerican.
Megaquake Heightened the Risk to Tokyo

If the group's stress-transfer calculations hold for the activated Tokyo area, “the seismic hazard for Tokyo has now likely doubled,” Toda said.

Kudos to you, TA
And be vigilant Tokyo...

reply to post by Olivine


Excellent, thanks.

Japan is a very complicated beast, sitting on the junctures of so many plates like that. It may be years, or it could be minutes, but Tokyo is going to get rocked. For another ten generations, scientists will study the dynamics of all this and still won't have a clue.

And the quakes continue to creep towards Tokyo:



earthquake.usgs.gov...

:shk:

I am of the firm belief that the Japanese in Tokyo have got to be the luckiest people on the planet at the moment, cause Mother Earth has spared them so far. She's just not going to wait much longer it seems.

I am of the firm belief that the Japanese in Tokyo have got to be the luckiest people on the planet at the moment, cause Mother Earth has spared them so far. She's just not going to wait much longer it seems.

I agree 100% TA...given the fact it's been slower than you first thought...what kind of time frame are you thinking now? and I know any answer is more or less a guess...but still wondering what you think

reply to post by okiecowboy


Oh Lord, I have no clue. But Mother earth seems to be providing as many clues as she can. It is just amazing to me that that whole area around Tokyo, with the southern zone right there, has managed to stand up to the incredible seismic barrage that it has without failing. Just fricken AMAZING, I tell ya.

reply to post by TrueAmerican


My Wife told me the reason why they chose Tokyo
as the main Capital was that the Kanto Plain
is relative stable compare to Nagoya or Kansai!

Originally posted by Human0815
reply to post by TrueAmerican

 

My Wife told me the reason why they chose Tokyo
as the main Capital was that the Kanto Plain
is relative stable compare to Nagoya or Kansai!

How could that possibly be true, after the 1923 Great Kanto Quake?

The earthquake had a magnitude of 7.9 on the Moment magnitude scale(Mw),[3] with its focus deep beneath Izu Ōshima Island in the Sagami Bay. The cause was a massive rupture of the Sagami Trough, due the exertion of enormous energy from the Philippine Sea Plate subducting under the Okhotsk Plate.

en.wikipedia.org...

Although, I guess since it has held up so admirably, maybe it is true to an extent.

Originally posted by TrueAmerican

Originally posted by Human0815
reply to post by TrueAmerican

 

My Wife told me the reason why they chose Tokyo
as the main Capital was that the Kanto Plain
is relative stable compare to Nagoya or Kansai!

How could that possibly be true, after the 1923 Great Kanto Quake?

The earthquake had a magnitude of 7.9 on the Moment magnitude scale(Mw),[3] with its focus deep beneath Izu Ōshima Island in the Sagami Bay. The cause was a massive rupture of the Sagami Trough, due the exertion of enormous energy from the Philippine Sea Plate subducting under the Okhotsk Plate.

en.wikipedia.org...

Although, I guess since it has held up so admirably, maybe it is true to an extent.

edit on Fri Jan 20th 2012 by TrueAmerican because: (no reason given)

"They" decided so with the help of many Gods, Tanukis^ ^ and Kitsune,
not with seismographic Data

(my explanation)

reply to post by JustMike


May God have mercy on Japan and the USA.

Some prophetic type sources are claiming the next big quake--over 9.X will be in the LA basin, So California.

I'd sure hate to see Japan get a big one near Tokyo but I'd certainly hate to see LA get one, too.

I don't know the validity of those sources . . . it's just a mish/mash I've come across without keeping track or making notes on them . . . the last month or so.

May God have mercy and delay any such and minimize any such . . . Sigh.

reply to post by TrueAmerican


I don't recall . . . is the plate Tokyo is on subducting under the plates South and East of it?

Or vice versa?

And what is the rate of subduction?

30+ million people is a lot of looming suffering.

Sigh.