Critical New Quake Could Mean Impending Disaster For Japan

Originally posted by TribeJoseph
reply to post by RANDOMguess

 

No offense, but if you want to pinpoint such a word as, "curse" on a people or nation, skip the two and put it on our world. In fact just as we all beheld, the victims that floated alongside their homes, boats, and vehicles, didn't have much of a choice at all. And so it is with every inhabitant of this earth in which we all reside. Cursed or uncursed, we are all here along for the ride.

Err hokay....I said as if they were cursed, with all there problems witch I wont list for obvious reasons. I didn't say they had a choice...that's not what a curse is. What do you think a curse is?. We are not all cursed I am living exceptionally well in comparison to Japan's unfortunate people. I don't think you understood what I said, and I definitely didn't understand why your reply was relevent to what I said.

reply to post by amarenell


and also in reply to post by drakus


You both ask good questions and frankly, I think a lot of us have been pondering the "where next" aspect quite a lot lately. There is no denying what TrueAmerican has already said about this: the triple junctions are of concern... (There is not just one triple junction, as the one in the Shizuoka region is equally worrying to the one in the ocean off the coast to the south-east from there.)

A day or so ago, someone asked what it means when a quake has a seismo trace that takes several minutes to die away. And not a huge quake like a magnitude 8-plus, but even some of those that have been in the mag 5 range. I've seen some of them today as I monitor seismos on GEE. There was a mag 5.9 earlier today that was showing on the seismos for at least 12 minutes before it calmed down again.

Typically, when a quake in that sort of range happens, you see a trace that might run a couple of minutes or so. This is about how long it takes for the shaking of the crust in the quake's region to stop. There's a jolt and a big trace and pretty quickly, it all settles down again. But some of these quakes are taking four or five times longer before that shaking stops -- or even more.

Here's what I think this indicates. I'm simplifying this a lot but I hope it'll make sense:
When a quake occurs, it simply indicates a rupture of some kind in the crust. I won't go into the details of the different types of ruptures because that's not important here. The thing is, something lets go. The crust gets jolted around as all that energy is released and then when the crust has sort of all crunched into its new position, things go quiet again.

In other words, the more fundamentally stable the crust is, the less time it needs to settle and stop moving around. And of course, the more unstable it is, the longer it needs.

Now, when the huge quake happened last Friday, it basically opened a massive rip in the crust. In the sea bed. The pressure of the sea water at depth is huge, and so naturally, water was forced down into that rip. A lot of crust that had been dry (perhaps for many centuries or even millennia) suddenly got the most almighty soaking.

Imagine that in your back yard you've got a wooden box full of dirt. It's dry, it's hard. It's been sitting there for ages. You give the side of the box a good hit with a hammer: Banng! Lots of cracks. Dust flies, dirt moves around. But after a few seconds, it all settles down. That's your typical quake.

Now imagine the same boxful of hard dirt, but this time you've got a few inches of water on top of that dirt. Not much. Just a few inches. Hit the side of the box as before, and besides the small waves you get, some of the water seeps down into the cracks. This makes things a bit unstable and some of the dirt will slosh around a bit. It won't be so hard as it was. That can be the effect of a smallish quake where there's some water over the crust. (Ditto for some ground water. How much groundwater can make a huge difference. Like in Arkansas. But there's a thread about Arkansas if you want to know what's happening there.)

Next, we change things a bit more. Now the box of dirt is deeper, and you've got a lot of water sitting in there. We have to be a bit fanciful here and imagine the dirt's so hard that the water doesn't seep in much. But whatever, you get the idea. This time, though, you don't just give the side of the box a whack with a hammer. You go and get a nice solid car with a big bumper on it and you drive it into the side of the box at a few mph to really hit it hard:



KA-BAMMMMMMMM!!

That's your magnitude nine quake. And yes, that would be getting close to the difference between a mag 5 and a mag 9.

There'll be a whole lot of shaking going on! And when it's all kind of settled down, you'll now have a box full of very sloshy mud. You only need to give the box a tap with your hammer now to see the difference. Whereas before it only made things shake a little, now you'll see the whole lot moving around. You'll even see waves. They are, in effect, like miniature seismic waves.

I think that's what we've got now. Those regions off the coast are like your box of dirt with loads of water in it after you've clobbered it with your car. It's incredibly unstable, so even mag 5 quakes are making shaking that just goes on and on. Too darned long for my liking.

And it will take a long, long time for all that saturated, bashed, ripped and battered sea floor to settle down and become stable again, because unlike the box in your back yard, that sea floor's down deep with huge water pressure on it and all that water which got forced in -- well, it simply has nowhere to go.

That's why I am really worried about those "smaller" quakes that show traces for eight, ten, twelve minutes or more.

They are a symptom of a much bigger problem. And they also make it much harder to try and guess what might happen next, because water is a lubricant for faults. That's proven. There are studies to show it.

I'll be honest: I haven't a clue what will happen next. I am only sure that things will not settle down for quite a long while. And the knock-on effects -- remote triggering of other regions? There are plenty of candidates and while some suggest the San Andreas, believe me, while that could be bad, it is by no means the biggest concern for the USA. The BIG one is the Cascadia subduction zone. But as this thread is about Japan I won't go into details on that here. There's plenty of good info on ATS about the Cascadia for anyone who wants it.

But Japan... I just hope they have some time to get things back in order before the next big one -- the one they have been expecting for quite a while.

Mike

reply to post by TrueAmerican

Thanks, TA. I appreciate it. I've pretty much offered my hypothesis in my previous post, but in response to what you've said I'd like to add that I'd expect quakes to continue popping up all over that region, especially offshore. If however, we see a very specific trend of mag 5-range (or bigger) quakes appearing in rapid succession on or close to the main subduction zone lines then that's a seriously bad sign. There have been some that fit the pattern, but more of them (in rapid succession) would pretty well seal it.

I'm hoping we don't see them and things just continue as they are, with a reasonable amount of semi-random quake epicenters. That would be fine and a good sign that things could be starting to stabilize. They are nowhere near stable yet. The fact that things have gone quiet for now doesn't reassure me at all. I'd like to see lots of semi-random releases of energy in nice, easy-to-manage mag 5-ish chunks. Lots and lots of them. But here, there and everywhere, not just on or near defined subduction zone boundaries.

Mike

Found this on 2chan. Can anyone explain what I'm looking at?

img196.imageshack.us...

It won't let me link it but it's on the 甘味 subforum on the second page.

www.2chan.net...

reply to post by JustMike


Thank you for taking the time to share this story on the Japanese culture,very informative!

reply to post by JustMike


That has got to be the best explanation I have read or seen for what is happening over there. Excellent!!!! People are failing to take that HUGE rift into consideration.

I hear ya on the long signatures. I got all excited when I turned GEE on again for the first time in ahwile. I had to take a few days away from my obsession....jut not healthy. When I saw a 40 minute plus span of prolonged rumbling...I am talking in the mag 5 range for a good 15 to 20 min and then it just went on and on, I really thought something horrid was about to give. Your explanation is both revealing and horrifying. I took a couple of sequencial screenshots last night, here they are, so people know what I am referring to:

So here is where it started. To give you an idea on the scale, the quake that started it all off was a 5.8 I believe.





So here is a sequencial pic. The quake to the far left here is the one on the far right in the first one. I believe it was a 5.6 or 5.7 further south:





The trace got smaller, but continued for probably another good 20 min or so after that last picture, with a couple of more quakes in the high 4 range thrown in. Very scary stuff.

Now there is some weird sort of trace on II.ERM. Anyone know what is going on with it?

reply to post by STL0913

HI STL,
that image is just a composite map showing the JMA "shindo" (shaking) scales and locations for some of the bigger quakes from 11 March. The JMA (Japan Meterological Agency) has its own scale for measuring quakes, which is based upon the amount of shaking that will be felt in a given region, compared to the shaking at the quake epicenter. The maximum on the scale is 7, and the mag 9.0 Mw (moment magnitude) quake on March 11 was rated a 7 by the JMA at its epicenter, but it was so powerful that even onshore there was a region where it was also a 7. Other regions further away felt it less strongly. But a "6+", for example, is still very strong indeed and indicates a seriously dangerous or destructive quake.

Here's a page on the Wiki about the JMA seismic intensity scale that explains it quite well.

Here's the reasoning behind the scale: what is important in Japan is not so much how big or strong the quake is, but how much damage it might do and where. (This is not always the same thing!) So, when there is a major quake and the alarm is sounded, the major TV networks like NHK immediately broadcast the alarm and show a map (supplied right away by JMA) that shows the expected amount of shaking in various regions and telling people what the scale is they can expect. The alarm also goes to major transport organizations and when it's significant, to schools.

It's a very effective alarm system. A couple of pages or so back in this thread here, I posted details of a quake, based on what was broadcast by NHK, with magnitude and location, a good 15 minutes before the quake showed on USGS. As I said in my next post, the first alarm went out so fast that the announcer in the Tokyo studio began to give details of the quake warning even before everything in the studio started shaking. In this case, they started to give the first warning in well under ten seconds. This can be crucial: it could for example give school children a chance to dive for cover, or perhaps allow a train driver to get a train stopped before it might derail.

These days, the JMA also releases the quake's details with the moment magnitude (Mw) figure that is used internationally, but for the local people, the one they listen for first is the "shindo".

Best regards,

Mike

reply to post by westcoast

Hi Westcoast and thanks for your comments. I could be wrong but it makes sense to me so I posted what I thought. It is a fact that water can lubricate faults, so we can't ignore that aspect in this major subsea event.

As to what's happening on .ERM right now, I wish I knew but I've lost all my GEE stations. They loaded but they've all gone off line. However, .ERM does get some weird traces on its E and N channels at times. It happened yesterday. The traces were totally nonsensical and didn't come close to anything on .Majo. They can be unreliable. I normally "x" them off and just watch the Z channels. That way I can also watch more stations.

When they're working, I mean...

EDIT: I just reloaded the stations and they're fine now. Nothing odd showing in Japan. They had a moderate quake at about 00:13 (ie just after midnight) UTC but nothing too dramatic. Could be in the 5's I guess. Depends exactly where it is. Looks more southerly than up north. But otherwise nothing special. For Japan these past few days, I mean.

Mike

Very interesting thread. Just looked at the latest 10 degree map on the USGS. Can someone explain why the overwhelming majority of aftershocks are situated underwater? Almost exactly delineating where the land meets the sea? There are only a handful that have occurred on land. As I understand it, that whole Eurasian plate on which much of northern Japan is situated extends upward. I'm wondering why we aren't seeing more aftershocks on the land itself.

JustMike, that is an interesting explanation of why the long decays. But I believe it has more to do with distance to station, fault length, and the resulting fundamental frequencies of the quakes.

For most of the activity centered around the 9.1, both MAJO and ERM are a considerable distance away, and this causes a blurring of the signal. Notice when they occur closer to MAJO, for example, the decays are shorter and the seismic waveform clearer- but also much higher in amplitude which is to be expected. And notice the closer quakes are further away from the main subduction zone, because of where MAJO is located.

Also the fault length plays a role too, because as the fault length increases, the fundamental frequency of the quakes are lower. And therefore the further they will travel and be picked up by the broadband stations. High frequencies are more easily attenuated. So generally speaking, the closer those quakes are to the main fault, the longer and lower the fault will resonate- which brings more of the low frequency signal into ERM and MAJO as the quake dies down.

So imo, it is a combination of all the above happening at once causing those long decays.

All these quakes are too close to me for comfort and seem to be moving closer.

reply to post by TrueAmerican

TA, I think that all of what you said is perfectly valid and those are certainly important contributing factors in what we see. Although I didn't raise those technical points myself in what I wrote, I have allowed for them; however, I still feel that even taking those factors into account, what I mentioned is also (IMHO) something that ought to be considered.

In any case, even if you might not agree with what I've said, I appreciate the opportunity to present my point of view.

Best regards

Mike

reply to post by JustMike


When I said all of the above, I was including your considerations as well- I should have made that clearer.

Now there has been another 4.5 south of Tokyo, right on the line, and close to where the 6+ hit. USGS might report, might not- because if they rate it just .1 mag lower, it won't show up at 4.4 on the USGS 2.5+/4.5+ List.

But it is right here:
www.jma.go.jp...

And again significant as it is very close to or on the southern zone. So that's three significant quakes on either side of Tokyo, on continental plate lines, plus all the other bigger quakes to the west on the lines, and the massive activity to the northeast.

So I suppose this is just another aftershock of the 6+ and it will go down that way. But did you see the signature of that 4.5 on GEE? Nasty, looked like a mini version of the 9.1. As in, something longer and deeper is stirring down there on the southern zone- initiator to the expected long due Tokai quake.

Another thing that came to mind on the long decays is the possibility of slow-slip faulting, where it slips kind of slower and with small magnitude.

And this link displays all the smaller quakes. If you'll check them out, there is a microquake swarm happening near the western NA plate edge:

www.jma.go.jp...

So add that to the warning signs as well. Signs of what? Hopefully nothing. I put my imagination back in the cage.

Still nothing. This is like waiting for one of Ron Weinlands predictions to come to pass.

there still having regular earthquakes over there including this one at a new location:

Friday March 18 2011, 23:34:30 UTC 35 minutes ago southwestern Ryukyu Islands, Japan 5.2 depth: 34.1
quakes.globalincidentmap.com...

are these islands on the subduction zone?

reply to post by reg

Yes. In fact, those islands exist because of the subduction zone immediately south of them. Here's a map that shows the quake location and the subduction zone (purple line):


Edit to add: the screen shot's quality is poor as it's a JPEG. The subduction zone line is south of the islands as I said, but the other two lines north of the islands are actually red in the original image and represent ridges. (End edit.)

Here's a LINK to the source page for the map on USGS. (This link will probably drop off within 7 days -- which is normal for "smaller" quakes. That's why I've posted a copy of the image.)

This zone runs all the way up past the southern side of Japan (which includes the region where the big quake occurred. Effectively, it's one very long subduction zone.

Mike

reply to post by TrueAmerican

Thanks for elaborating on that point, TA. I had misinterpreted what you meant by "all of the above". All is cool.

This recent quake close to the subduction zone but all the way over in the Ryuku Islands is interesting. However, it is quite a seismically active area (as the Historic Sesimicity maps attest), so I'm not sure whether we can attach any great significance to it. To my way of thinking, it's certainly worth noting, but personally I won't be regarding it as a possible indicator of anything bigger unless we see a few more there in fairly short order -- or alternatively more popping up along a line that follows close to the subduction zone and heads back in towards the main islands of Japan.

I feel the same about the couple of mag-4 range quakes they had in the sth Taiwan region in the past few days or even the one down near Mindanao a short time ago... Those regions are also very active and always have been so I don't see them as anything to go by in terms of the zone over near the triple junctions (especially the one offshore from Tokyo).

Ummm... I know that you know about these regions like Taiwan the Philippines and how active they are, but there might be some members who are new to this and perhaps don't know. I wouldn't want anyone to be unduly alarmed. That's why I mentioned it.

Basically I agree with you: far, far better if nothing big happens.

Mike

I've used the analogy of a string on an instrument before and I will again here in supporting what Mike has said about the large quake breaking up a substantial portion of the fault. As you loosen a string it be olds less taut and will vibrate for a longer period of time. So with such a long portion of the fault damaged, it seems quite plausible that subsequent quakes would rattle he loose crust for longer periods of time.

In looking at the map of the Japanese quakes on the site TA linked, the quakes occurring along the fault that goes north and east of the fault where the large quake took plae is clearly delineated. So I can see how having this area show more activity be cause for concern.

I akso have to add, Mike, that your explnation of the events including the live speech by the emperor is a much more relevant interpretation than ANY I have yet to read or hear. I may have eventually ha these things dawn kn me myself, but you certainly crystallized it quite well.

reply to post by jadedANDcynical

Thank you... I hadn't thought of the loose string anology. It makes sense and I'll have to look into it more. Thank you als for your comments about what I wrote the other day about the Emperor. You jogged my memory, in fact, because I wrote another piece about the Emperor's speech earlier today (about 16 hours ago -- it's now 3:45 am and I can't sleep), so I'll paste it in here. Again, it's only my take on things but if any think it's worth considering then it was worth writing it. Anyway, here it is:

I took another look at what the Emperor said in his unprecedented speech. Two things stood out for me. One was how he stated that all Japanese people will work together to help those who have suffered and to effect recovery.

There are several layers of meaning here, but not being Japanese myself I certainly don't claim to appreciate all of them. But as the Emperor was, on the surface, stating the obvious, his primary audience -- the Japanese -- would have immediately begun to consider what he was really saying.

One thing that stands out to me is that while Japan is accepting foreign help, this must not be seen by anyone (in Japan) as an admission of being unable to cope as a nation in the long term. Implicitly, this is also the Emperor's way of saying that there is no shame in accepting this help. It is temporary and it's necessary to accept it, just as they offer help to others in time of need. (The Japanese sent trained rescue workers to New Zealand last month, for example.)

I don't want to get too involved here, but from what I've learned from Japanese people, there is a very delicate balance between offering help, and at the same time allowing the ones who are in need of it to maintain "face" -- to keep their dignity. This is what I meant by saying there is no shame.

If this all seems rather confusing then don't worry. It is, if we only try to look at the surface. When any official speaks, it's necessary to look beyond the mere words. And when the Emperor gives a speech as he did, almost everything he says means a lot more than it appears.

The Emperor used the future tense -- all Japanese people will work together -- implying what is to happen as they go forward. Accepting help now is quite correct and may be done without loss of face, because the lives of the people are more important than anything. The Emperor has made that clear. But going forward, all Japanese people will work together.

This also sends a very polite message to foreign governments that their help, while gratefully accepted, will not be needed for long.

Now, I wouldn't want anyone to take that the wrong way. The Japanese people are deeply grateful for the aid they are receiving. But they will feel much better when they know they can move forward and do things on their own.

The second point I'd like to address is much more serious and already, we are seeing the results of it. Because in this case it's essential to have it word-for-word, I'll quote from one of the many transcripts of this section that are available online:

"I am deeply concerned about the nuclear situation, and hope it will be resolved," he said. "I hope things will take a turn for the better."

First point: "I am deeply concerned about the nuclear situation..." I cannot over-emphasize how crucial this is! If the Emperor is "concerned", then the situation is bad. But deeply concerned? Considering how the Emperor is the absolute essence of all that is Japanese, if he is deeply concerned then all his people should be as well.

But why is the Emperor deeply concerned? At the time he made this speech, we were hearing reassurances that everything was either under control or soon would be. But nothing is that simple. Here's why:

Second point: "...and (I) hope it will be resolved...I hope things will take a turn for the better."

The Emperor used "hope". Not just once, but twice. This is also of great importance. He made certain that no-one who was listening and taking in the message would miss the significance of that word.

Let me put it this way: if instead of "I hope" the Emperor had substituted a phrase like "I know" or "I have been assured" or even "It is my sincere belief" (with the latter, being a little more indirect, the more likely phrase), then people would have a reason to breathe a little more easily, because that would mean that the Emperor's advisors had assured him the situation was in hand and would not get worse.

Even if he had used a conditional form and said, "It is my sincere belief that the situation should soon be better," that would be a fair indicator of cautious optimism by the experts who advise the people who advise the Emperor.

But no, not even that. The Emperor used this unprecedented speech to let the Japanese people know that not even his best advisors could assure him this situation was being brought under control or even that it will be or should be soon. All the Emperor could tell them was that he hoped it would be, because at the present time, there was no resolution of this situation.

And I expect that was the signal for the diplomatic missions. This was what they needed to know: has the Emperor been informed that things are under control at these stricken nuclear power plants? No, he has not been so informed. He has not even been informed that they will be. His statements made that utterly clear. If he says "I hope", then it means "at the present time as I speak, nothing is certain and neither is the future".

And for the Emperor's people? It was also the signal for people in the potentially affected regions to evacuate with all speed. And according to news reports, they have been doing so. The evacuation numbers are growing.

And with what we can glean from the news reports, so are the problems with the reactors.

Mike

So now a 5.9 (JMA says 6.1) hits as the activity appears to make its way further inland, indicated by the circled area:



It will be an additional area to watch, cause that's a pretty good sized quake. Another big one could occur there as new slips occur deep underground.

Since my imagination is caged, I won't speculate on how that could apply to the bigger picture, if there is one.

JMA can alert using the P-wave arrival as long as it's out in the ocean, but when the P-waves get there at nearly the same time as the S-waves with epicenters on land, that system will be of little use. What good is two seconds when it takes that long to comprehend the message? By that time you are shaking. So the additional danger of these land epicenters are such: it effectively cancels their warning system for the epicenter location. If it's a real big quake though, it can still give a few seconds warning to the outlying areas.