Japan warned by seismologists to stay vigilant after powerful quake

Seismologists on Sunday warned Japan to stay vigilant for the next "Big One" after a powerful 7.8-magnitude earthquake struck off the coast of the quake-prone nation, injuring a dozen people...

Some experts warn recent quakes and volcano eruptions may be signs that areas near the country are entering an active phase of crustal changes.

"I can say Japan is in an active stage now," said Toshiyasu Nagao, head of Earthquake Prediction Research Centre at Tokai University.

"Considering the geographic location of Japan, we can say the current activities are rather normal and it was too quiet" before the 2011 jolt, Mr Nagao told AFP news agency.

"We should be vigilant by knowing that it is no wonder that an earthquake sizeable enough to affect our society can occur anytime in the future," he said.

www.telegraph.co.uk...

Hmm, this sound familiar? For anyone following our recent thread on this quake, JustMike and I were exploring that very possibility. Well now it looks like we aren't the only ones concerned about these quakes. But in our story, we gave you pretty pictures and more analysis.

So now after more digging, I am going to add some new information. It turns out I pulled a slab depth profile of the 7.8. We do this to get a view of other quakes that have happened near there to see if the new quake roughly matches the other depths of nearby previous quakes. Now initially, I stated in that thread that from my memory, I didn't think that quake's depth looked right, or "at a typical depth" for its location. But then upon a cursory glance at the slab profile, it seemed more like it was at roughly the right depth.

But now I have come across some previous info, which may prove my initial reaction correct. Or more correct than my second reaction. The point is, that after analyzing the depths of previous quakes in that immediate spot, I am going back to my original reaction. This quake I am going to claim IS anomalous, and does not fit the depth profile. The closest quake anywhere near that spot with a very deep hypocenter was about 400 km deep. All the others in that immediate area were much more shallow (30- 200km deep) and conformed much better to the slab profile. This depth of some 677 km deep for the 7.8 is indeed way too deep for its spot.

So now what exactly does that mean? Well, it could mean that they got the depth wrong on it. So watch for any change in depth on that quake, cause it already came down from its original 690+ km depth to 677 km. Or it means that the quake originated from somewhere that isn't even supposed to be there at that location, further adding confusion and making a mockery of these slab depth profiles. Now I saw this days ago. But I'd be willing to bet this little anomaly might have something to do with why seismologists are now warning Japan to be on the lookout. Because that quake is out of place. They probably checked and rechecked those arrival times and wave reflections, to verify the hypocenter (and epicenter) locations, and came up scratching their heads.

AGAIN!

Remember how no one thought a 9.0 could ever EVER hit the spot that it did, primarily because they didn't have evidence of enough fault length to support a 9.0. They thought a 7.5 would be tops in that spot.

So now they are getting another lesson in "Don't try and define that which you cannot." But I busted em trying to cover it up I think. Notice no mention of this in the article. Ha.

Leave it up to ATS. We'll sort it out one way or the other. Now I could be wrong... But take a look for yourselves at previous quakes near that 7.8 and tell me what you see...

Looky looky

a reply to: TrueAmerican

How does one "stay vigilant?"

Kazuki Koketsu, professor with the Earthquake Research Institute at the University of Tokyo, said the latest tremor was unlikely to be a sign of a potential big jolt in the capital, which was devastated by an massive earthquake in 1923.

"But it is important to regard it as an opportunity to prepare for a future quake," Mr Koketsu told TV Asahi.

www.telegraph.co.uk...

originally posted by: Phage
a reply to: TrueAmerican

How does one "stay vigilant?"

By watching ATS and not believing the lies by omission.

a reply to: TrueAmerican

Ok.
I'll be sure to tell Japan to watch ATS.

By "omission", did you mean avoiding certain quotes from that article?

originally posted by: Phage
a reply to: TrueAmerican

Ok.
I'll be sure to tell Japan to watch ATS.

Ha. I bet they already do.

No, I meant the omission I have explained in the OP. After analysis, and EXTENSIVE analysis, I'm sure, they now know something is very wrong with that quake. But it took ATS to tell you what it is- or at least, what I suspect.

And here, I'll give you some more food for thought:

We pointed out in the other thread that its main aftershock was only like 30km deep or so. Well guess what. That depth on that 6.2 is now a mere 8.7 km after revision! Look-

earthquake.usgs.gov...

And here's the other kicker- its closest aftershock of 4.4 was only 427 km deep. Now granted that is still pretty deep, but it defies the slab depth profile even further, because that 4.4, should have been even deeper than the 7.8 where it sits on the map! It's further to the left than the 7.8.

So yeah, that 7.8 is another mystery, and like I said, either they got the depth very wrong- and this can happen on super deep quakes because of bad flag picks and misidentifications of love and raleigh waves- or if it's right, then it is anomalous. Big quakes that deep are hard to read, partly because of the many reflections taking place in the earth layers.

Thanks TA for all this analysis and some pretty important information. I appreciate how you break it all down in terms for us quake illiterate folks to better understand the situation. Like you said, something the main stream would never do and we'll only learn here at ATS.

well its japan
there will be earthquakes

unfortunately as we have seen already
if the profits are greater for the PTB (tepco ge etc ) at the expense of the Japanese ( and anyone else ) people
no amount of vigillence will save them
or US

certainly the truth about some of these disasters is easier to be found at ATS then on TV, or from the government