Gut wrenching stuff, the videos look like a Hollywood disaster movie the way the water was moving entire houses and devastating everything in its path. We can only hope the new tsunami warning system does its job in other parts of the world. My thoughts are with you all out there...
When you consider the strength of the shake with the duration (almost 5 minutes instead of 30 seconds) it was definitely a massive release of energy that would dwarf other quakes in the last couple of centuries.
At least it is the area with a good Tsunami warning system, but the further away you are from the epicenter, the results are diluted, but can be re-energized by local shore conditions.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
I guess the seismic reports on the duration were inconclusive based on a short video clip. The seismology readings are the real source for period and magnitude and assessment on a large scale.
It was far stronger than the recent Northridge quake where I did engineering damage assessment and was able to see damaged buildings after the quake and then again a day later after the aftershocks. the aftershocks were the revealing
It is fortunate that Japan has good codes regarding seismic activity. I was in a lab that had shaken 3 or 4 story (full size material segments) for code and design purposes.
The problem is blending the results into meaningful standards for life safety codes and ultimate "last forever under any possible condition" standards.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
8.9 is a monster quake, and I think this will demonstrate the value of emergency preparation and the Japanese building code. In any other country the fatalities could have been 10-100x higher. Nevertheless this is quite serious, and we are praying for all affected by this.
What looked like a nuclear containment building, a cube-shaped structure of (I am assuming) reinforced conrete, had a huge wide crack along one side. No radioactive releases so far that I know of. Apparently every house has a natural gas shut-off valve that is activated by seismic activity above a certain threshold.
The pressure in the reactor is up 1.5 times the normal pressure.
The radiation is ?100? times the normal level.
The exclusion zone has bee increased from 6 to 10 kilometers.
None of the cooling towers are operating.
113 pre and aftershocks over magnitude 4.6. Curiously there have been a number of aftershocks over magnitude 6 spaced about an hour, then decaying in multiples of an hour.
Have read about 88000 unaccountably lost people even if officially casualties remain under 1000.
Pressure stable within the reactor at nuclear reactor in Fukushima, but rising in the containment structure, ability to control the temperature lost. 2nd Evacuation around.
That was a doozy! I was working on the fifth floor of my building in Kanagawa (near Tokyo) when everything started swaying. We had a small earthquake Wednesday or Tuesday (epicenter in Miyagi I think) and everyone seemed to think it was going to stop soon. My boss put on his hard hat as a joke. Then it got worse and everyone put on their hard hats. After the computers started moving around it was time to duck and cover under the desks.
The big shaking seemed to last at least a minute or two. There wasn't any serious damage to our building, a few computers falling over. I'm not sure about the factory, but I didn't hear of any injuries. I'm just glad the buildings around here are built sound, especially after seeing the pictures of NZ a few weeks ago.
This experience has really made me thankful for all you structural engineers. It's one thing to see it on tv, and another to be hiding under your desk. I'm off to work to see what's going on.
Thankfully this was as deep as it was about 24km. Had it been shallower and at 8.8 it would have caused unimaginable devestation. And believe me I'm not trying to down play the devestation there now. I just want to point out that terribly devestating EQ are those that are in the less than 10 to 15km range. It just goes to show what a powerful 8.8 deep in the mantle can do.
Regards,
Qshake
Eng-Tips Forums:Real Solutions for Real Problems Really Quick.
Watching this devistation occur on the t.v., has made me curious as to how to secure more lives through design-integrated systems. I am currently feeling the urge to research and up-grade methods for future designs, in areas which can and will be affected by earthquakes and other natural-disasters.
Does anyone have any idea, exactly how high or how far the largest movement had reached, between each-one of these simultaneous earth-movements. This comments may sound like I'm joking, but it's an issue I'd like to dive into a bit more.
My sympathies to anyone who is apart of this disaster, or who has family which is in Japan or the surrounding areas.
The largest movement? Researching these news I saw a documentary interviewing 1 surviving father and son that were brought in their boat from a bay to around 1500 ft above sea level abot 40 years ago.
From what seen it is clear the accumulation of fossile animals (congealed and not) of every kind in cracks all over the world at heights akin to that and more 11500 years ago was likely caused by some brutal washing like the one of this tsunami ... or worse.
I have read (I think in La Violette books) of true 300 to 800 meters tall seawalls running over China to dump the wash at the northern Siberian coast, where the submerged trunk fossils can still be found. Indian legends are quoted for akin fearsome water wall heights.
These waves are thought not to be caused by the vibratory ringing of some submarine earthquake, but for some inclination of the terrestrial axis, where water from the before bulging elipsoid is searching their new equilibrium in the wobbling movement; essentially upon the change of axis they found to be at a height over what was before firm land and so fall therein.
This kind of scenario is something nothing of the kind that our current technology can defend us for now. Nothing sort of giant ark vessels continuously available to overcome the humours of one turned dangerous planet is enough; plus, what such spaceships must stand till either the home planet is stable and livable again or travel to another one.
I once read that humankinds were always in progress just in the programmed instinct of trying to build the ark able to bring them to another planet before the conditions make it unlivable. It may prove to be true.
Not to mention the channelling "knowledge" of chairman of anthropology seat (so says the back cover of one of his books) George Hunt Williamson being informed that the solar system was entering the gaz bubble of one giant star in formation, the traversal of which would take 250000 years ... not being able to survive the enterprise. Maybe we are fortunate that he was chairman of anthropology and not of engineering, but, who knows.
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