Japanese Earthquake - was it really that devastating?

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In summary: The Japanese may react like anyone else would, that is incorrectly when exposed to an earthquake, but their engineering is still the best in the world for an earthquake. Most of the damage and deaths from the quake are from the tsunamis generated by the quake. Engineering to prevent tsunami damage still needs a lot of work, but there structures held up admirably.The Japanese may react like anyone else would, that is incorrectly when exposed to an earthquake, but their engineering is still the best in the world for an earthquake. Most of the damage and deaths from the quake are from the tsunamis generated by the quake. Engineering to prevent tsunami damage still needs a lot of work, but there structures held up
  • #1
Simfish
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http://www.youtube.com/user/citizentube#grid/user/0870831CE43351E1

http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/c0001xgp/ [Broken]

Yes, it was the most powerful Japanese earthquake in terms of the amount energy released. But the youtube videos show that the shaking wasn't even that bad (in Tokyo, anyways) - and plenty of items, even laptops, still managed to stay on the desks. It just lasted for a long time (around a minute). Now, Tokyo is quite some distance away from the epicenter of the quake, which reduces the magnitude quite a bit (plus, the energy is also distributed over the entire fault, rather than localized). Even if you look at the usgs website, there are no areas where the perceived shaking was severe at all.

And even though people say that Japanese citizens are the most earthquake-trained residents in the world, the videos show little evidence for that. There were so many people who simply stayed inside, standing inside the building as the earthquake shook. The people in their homes simply ran outside. Meanwhile, all the official US sources tell us NOT to run outside, and to immediately drop and to take cover. None of the Japanese did that. Are the Japanese doing something wrong, or is there something wrong with the official earthquake advice in the US?
 
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  • #2
Well, I mean how big of a data sample do you really have to say that "None of the Japanese did that"? Also, remember that a good infrastructure includes buildings on shock-absorbers that, if they did their job correctly, would dampen any shaking.
 
  • #3
Hm, well, the data sample I had consisted of 4 videos. It's certainly not a data sample that's rigorous enough to say "None of the Japanese did that" - it was just enough to convince me that a significant fraction of Japanese didn't do that, which was my actual point (although I should have made that clearer in the OP).

Oh, good point about the shock-absorbers.
 
  • #4
The Japanese may react like anyone else would, that is incorrectly when exposed to an earthquake, but their engineering is still the best in the world for an earthquake. Most of the damage and deaths from the quake are from the tsunamis generated by the quake. Engineering to prevent tsunami damage still needs a lot of work, but there structures held up admirably.
 
  • #5
Subductionzon said:
The Japanese may react like anyone else would, that is incorrectly when exposed to an earthquake, but their engineering is still the best in the world for an earthquake. Most of the damage and deaths from the quake are from the tsunamis generated by the quake. Engineering to prevent tsunami damage still needs a lot of work, but there structures held up admirably.

And to add to that, in the end you're trying to combat forces that are just unimaginable compared to what we see in the real world on a day to day basis. I think the real question will be how quickly the areas most hardly hit will recover. One thing I wonder is how long it takes for the water to recede from areas that at this point are just completely underwater (if they do at all!).
 
  • #6
Simfish said:
And even though people say that Japanese citizens are the most earthquake-trained residents in the world, the videos show little evidence for that. There were so many people who simply stayed inside, standing inside the building as the earthquake shook. The people in their homes simply ran outside. Meanwhile, all the official US sources tell us NOT to run outside, and to immediately drop and to take cover. None of the Japanese did that. Are the Japanese doing something wrong, or is there something wrong with the official earthquake advice in the US?

Disaster Prevention Guide in Foreign Languages :
http://www.city.hachioji.tokyo.jp/dbps_data/_material_/localhost/soshiki/gakuentoshibunkaka/kokusaikoryu/bosai/bosaiEnglish.pdf [Broken]
(from http://www.jpss.jp/en/life/crisis/1/#2)

While trying to find what Japanese government tells its citizens to do during an earthquake, I also found:
Disaster Risk Management Profile
http://emi.pdc.org/cities/CP-Kobe-April-06.pdf [Broken]
 
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  • #7
Simfish said:
Hm, well, the data sample I had consisted of 4 videos. It's certainly not a data sample that's rigorous enough to say "None of the Japanese did that" - it was just enough to convince me that a significant fraction of Japanese didn't do that, which was my actual point (although I should have made that clearer in the OP).

Having been through the two that hit Christchurch NZ, yes, that really surprised me too. And there were more than four clips I saw.

People do seem to divide on those who react and those who don't. In my office, as the roof started to fall, I saw some standing looking up in bewilderment, while others like myself were under the desk pretty smartly.

Perhaps it is a cultural thing. With a conformist culture, the Japanese may need more permission to panic. :smile:
 
  • #8
One's actions would be determined by the type of building in which one finds oneself, and upon the magnitude of the quake.

In some cases, it may be appropriate to get under a desk to avoid being hit by debris from a ceiling. In other cases, it may be appropriate to get to a stairwell or stand near a column. However, some of these options may be futile if the force of the quake is sufficient to cause the building to collapse. And then it may depend on how much mass is above one. Two buildings in Christchurch completely collapsed. In one case, the stairwell was the best location to be.

As for running outside, in high rise buildings falling windows and building facades may cause severe injury. At one two story building in Christchurch, a man ran out of the first floor shop only to be crushed by bricks falling from the front of the building. His mate was trapped inside and injured by falling material, but was able to make it out the back.

Some of the buildings in the central business district (CBD) of Christchurch experienced acceleration well above design, so it was not surprise that they collapsed.

The mag 8.9 is a rather strong event, but it was about 80 miles (~140 km) offshore.

The reaction of people would be influence by their perception of the event. If it seems minor, then perhaps they wait to respond. If the event is strong, they might run or panic, unless the build up is slow, in which case they might delay in response.
 
  • #9
Astronuc said:
One's actions would be determined by the type of building in which one finds oneself, and upon the magnitude of the quake.

In some cases, it may be appropriate to get under a desk to avoid being hit by debris from a ceiling. In other cases, it may be appropriate to get to a stairwell or stand near a column. However, some of these options may be futile if the force of the quake is sufficient to cause the building to collapse. And then it may depend on how much mass is above one. Two buildings in Christchurch completely collapsed. In one case, the stairwell was the best location to be.

As for running outside, in high rise buildings falling windows and building facades may cause severe injury. At one two story building in Christchurch, a man ran out of the first floor shop only to be crushed by bricks falling from the front of the building. His mate was trapped inside and injured by falling material, but was able to make it out the back.

Some of the buildings in the central business district (CBD) of Christchurch experienced acceleration well above design, so it was not surprise that they collapsed.

The mag 8.9 is a rather strong event, but it was about 80 miles (~140 km) offshore.

The reaction of people would be influence by their perception of the event. If it seems minor, then perhaps they wait to respond. If the event is strong, they might run or panic, unless the build up is slow, in which case they might delay in response.

Would I be correct in assuming that an 8.9 UNDER Sendai, or Tokyo, or any major city wouldn't have left much of a city behind... regardless of preparedness?
 
  • #10
nismaratwork said:
Would I be correct in assuming that an 8.9 UNDER Sendai, or Tokyo, or any major city wouldn't have left much of a city behind... regardless of preparedness?
Yes - I would expect significant destruction of buildings if they had an 8.9 directly underneath.
 
  • #11
Astronuc said:
Yes - I would expect significant destruction of buildings if they had an 8.9 directly underneath.

Mother nature can be such a... female dog. I wonder what they're thinking now in relation to Tokai... I'd be terrified.

Is there any technology which can allow a free-standing structure to withstand that kind of event, or is it just too much?
 
  • #12
I don't think you can blame any female here, dog or mother (nature) or goddess (Gaia). Don't forget that Earth is a highly dynamical object, comprising a set of different gyroscopes in a complex gravity field, providing torques and precession and other wobbles, in combination with heat convection flows. What could be a small adjustment to the forces for Earth can be a devasting disaster for us.

Things like this and much worse have happened in the last 4.6 billion years and unfortunately it's not going to stop now mankind has covered the Earth with civilization that is completely unable to cope with these things. Luckily those events a are very very rare and in another couple of decades it's probably reduced to just another historic note.
 
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  • #13
Keep in mind that much of the devastation associated with this earthquake came from the tsunami that it generated which hit the Japanese coast.
 
  • #14
Here is a picture of some of the devastation caused but the tsunami.

http://www.dailygalaxy.com/my_weblog/2011/03/image-of-the-day-japans-quake-tsunami-devastation.html#more

I haven't looked at any of the other links, so I apologize if this picture has already been showed in video or just a still pic.
 
  • #16
Andre said:
I don't think you can blame any female here, dog or mother (nature) or goddess (Gaia). Don't forget that Earth is a highly dynamical object, comprising a set of different gyroscopes in a complex gravity field, providing torques and precession and other wobbles, in combination with heat convection flows. What could be a small adjustment to the forces for Earth can be a devasting disaster for us.

Things like this and much worse have happened in the last 4.6 billion years and unfortunately it's not going to stop now mankind has covered the Earth with civilization that is completely unable to cope with these things. Luckily those events a are very very rare and in another couple of decades it's probably reduced to just another historic note.

I was being factitious Andre, I'm sorry if that wasn't apparent. I accept that we live on a dynamic world, and my genes are thrilled to have a nice firm geomagnetic field! I can put things in perspective and even accept that this is as much a part of the process of life as death, but it's still a terrible thing to see.

@scupydog: The reactor will never EVER operate again, ever, beyond that... it's coolant, so yes it's a last resort as far as cooling goes AFAIK.
 
  • #17
  • #18
Someone on another site posted a figure from a site looking at an increase in earthquake activity in the long term.

http://www.earth.webecs.co.uk/ [Broken]

USGS also looks at trends. Here are some statistics.
http://earthquake.usgs.gov/earthquakes/eqarchives/year/graphs.php [Broken]

It's noisy - but there seems to be a slight increase in frequency of strong earthquakes of 8 or greater since 1990. Any long term increase could also reflect an improvement in monitoring.

Some of the oldest nuclear plants were built in the 1960's/1970's, and thus reflect a seismic activity assessment up to that point.

I have to wonder if things have changed a little along the western Pacific Ring of Fire, or in generally around the ROF.
 
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  • #19
Astronuc said:
Someone on another site posted a figure from a site looking at an increase in earthquake activity in the long term.

http://www.earth.webecs.co.uk/ [Broken]

USGS also looks at trends. Here are some statistics.
http://earthquake.usgs.gov/earthquakes/eqarchives/year/graphs.php [Broken]

It's noisy - but there seems to be a slight increase in frequency of strong earthquakes of 8 or greater since 1990. Any long term increase could also reflect an improvement in monitoring.

thats only really a short term view, if you look at long term trends 100 - 200 yrs the avg hasnt changed.
On avg there is still only 1 x M8+ / year and ~ 15 x M7.0 - 7.9 / yr

2004 was a bit of an anomaly in the big scheme with 4 events > than M8


Dave
 
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  • #20
The Japanese earthquake wasn't just "rather strong", it was gigantic! Magnitude 9.
For comparison the "Big One" that's expected to strike Los Angeles soon would be about a magnitude 8. That's 1/32 as much energy as this earthquake! The San Andreas fault near Los Angeles is capable of about that size of an earthquake.
I've read that this may have been a once in a millenium event for Japan. A similarly gigantic tsunami struck Japan in 869.
Areas of Japan that were above sea level are now below ...
Maybe there will be new lakes.
Laura
 
  • #21
I think off the top of my head, the largest known magnitude was 9.5 in South America this was a puppy in comparison to that but then it's a pretty big puppy!
 
  • #22
Does anyone have experience in interpreting USGS shakemap data? I was trying to guess-estimate the g forces at the Fukushima Daiichi reactor during the quake and someone directed me to the usgs data. I seem to have to be having some problem understanding it.

http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/c0001xgp/" [Broken]

When I click through to the underlying data, I seem to get something close to .6g for the Max Acc (%g) at the reactor.

http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/c0001xgp/stationlist.html#sFKS001" [Broken]

FKS001, which is closer to the epicenter reported Max Acc (%g) 63.1432 and FKS004, which is further away reported 57.9340. I used 37.421 141.032 as the location of the reactor. The distances to the epicenter in the table appears to be wrong. It is much smaller than what I get in Google Earth or what the USGS is reporting.

http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0001xgp/" [Broken]

Is there a difference between Peak Acceleration and Max Acceleration? Nuclear reactors usually deal with Peak Acceleration. I'm also a little concerned about the "Not Reviewed by Human" caption on the shakemap.
 
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  • #23
yes interesting, the distances are VERY wrong. event the closest point on the coast, directly west of the epicentre is ~ 95km !

Difference between Peak and Max I suspect you will find Peak = an instantaneous reading, whereas Max is an intergrated, over several seconds, reading
I have been known to be wrong haha ;) unfortunately I don't have any contact with my university geology professors any more. But I guess an email to the USGS would soon clear that up. As well as the distance problem.

Dave
 
  • #24
davenn said:
yes interesting, the distances are VERY wrong. event the closest point on the coast, directly west of the epicentre is ~ 95km !
Dave

The only thing I could think of, is that the routine that they are calling is returning a result in miles or nautical miles and they are labeling it kilometers. Getting your units mixed up is a popular way to shoot yourself in the foot. It could be hard to catch if no one was using it in their calculation.
 
  • #25
what's crazy is that japan was actually prepared for a tsunami and something like this...at least they thought!...i wonder how prepared we are?...i also wonder if they are going to raise gas prices even more now , blaming this?
 
  • #26
megumi norito said:
what's crazy is that japan was actually prepared for a tsunami and something like this...at least they thought!...i wonder how prepared we are?...i also wonder if they are going to raise gas prices even more now , blaming this?

The two reactor plants most at risk are San Onafre and Diablo Canyon. San Onafre has a 30 foot seawall and Diablo Canyon is at the top of a cliff, so it looks like they certainly considered it. These reactors are PWR and frankly make the BWR in Japan look flimsy. Diablo Canyon is more problematic since there are active faults in the area.

Here is a list of all the US Reactors with a Google map at the bottom.

http://world-nuclear.org/NuclearDatabase/rdResults.aspx?id=27569"
 
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  • #27
I'd just point out, a massive quake would do a lot, but nothing like a tsunami. It was, we have to remember, the tsunami that nailed Fukishima.
 
  • #28
megumi norito said:
what's crazy is that japan was actually prepared for a tsunami and something like this...at least they thought!...i wonder how prepared we are?

Geologists actually didn't expect that fault to have such a big earthquake. http://sciencenews.org/view/generic/id/71281/title/Japan_quake_location_a_surprise People were not prepared at all for the giant tsunami that resulted. A similarly huge tsunami happened in 869 and in 2001 researchers predicted another one was about due. http://wwwsoc.nii.ac.jp/jsnds/contents/jnds/23_2_3.pdf [Broken]

I don't think they could have built a seawall that would shut out such a powerful tsunami. All they could have done would be to not live at low elevations right next to the ocean, or have some kind of incredibly good and fast warning system.

As well as being a huge shock, the quake was optimized to produce a big tsunami, because it had a shallow focus, according to the Japan Meteorological Agency.

I wonder what they are going to do with the large ships that were carried inland by the tsunami. Leave them there are museums?

Laura
 
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  • #29
lark said:
Geologists actually didn't expect that fault to have such a big earthquake. http://sciencenews.org/view/generic/id/71281/title/Japan_quake_location_a_surprise People were not prepared at all for the giant tsunami that resulted. A similarly huge tsunami happened in 869 and in 2001 researchers predicted another one was about due. http://wwwsoc.nii.ac.jp/jsnds/contents/jnds/23_2_3.pdf [Broken]

I don't think they could have built a seawall that would shut out such a powerful tsunami. All they could have done would be to not live at low elevations right next to the ocean, or have some kind of incredibly good and fast warning system.

As well as being a huge shock, the quake was optimized to produce a big tsunami, because it had a shallow focus, according to the Japan Meteorological Agency.

I wonder what they are going to do with the large ships that were carried inland by the tsunami. Leave them there are museums?

Laura

I suspect they'll be treated as debris... they'll definitely make some kind of memorial, but I suspect it would be more understated than a large vessel.
 
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  • #30
nismaratwork said:
I suspect they'll be treated as debris... they'll definitely make some kind of memorial, but I suspect it would be more understated than a large vessel.
I mean, ships are built near the water. It would be rather hard to tow such a thing around.
 
  • #31
lark said:
I mean, ships are built near the water. It would be rather hard to tow such a thing around.

I suspect the ships will have to be cut up and hauled off as scrap. Some of the boats might be hauled back to sea if they are repairable.
 
  • #32
joelupchurch said:
I suspect the ships will have to be cut up and hauled off as scrap. Some of the boats might be hauled back to sea if they are repairable.

I think leaving a large ship there as a memorial, with a museum built into it and all sorts of pictures of the disaster and tsunami devastation, would be rather beautiful.

Like this one: http://i.telegraph.co.uk/multimedia/archive/01852/ships-620_1852083i.jpg

It needs to be fixed up a little, but I wouldn't waste the tsunami's efforts, rather route the road around it and turn it into a spectacular tourist attraction. Japan is going to need tourist attractions ...
 
  • #33
lark said:
Geologists actually didn't expect that fault to have such a big earthquake. http://sciencenews.org/view/generic/id/71281/title/Japan_quake_location_a_surprise
Laura

That really shows his lack of understanding of megathrust systems and their potentials !

quote...“This area has a long history of earthquakes, but [the Sendai earthquake] doesn’t fit the pattern,” says Harold Tobin, a marine geophysicist at the University of Wisconsin–Madison. “The expectation was high for a 7.5, but that’s a hundred times smaller than a 9.0.”

that almost makes me laugh. Wonder what sort of marine geophysicist he is ? maybe he doesn't specialise in plate tectonics ?
Any, I repeat ANY major thrust system is capable of producing such events, That is just a given especially when you look back in history at the different regions around the Pacific and Indian Oceans.

Cheers
Dave
 
  • #34
lark said:
I think leaving a large ship there as a memorial, with a museum built into it and all sorts of pictures of the disaster and tsunami devastation, would be rather beautiful.

Like this one: http://i.telegraph.co.uk/multimedia/archive/01852/ships-620_1852083i.jpg

It needs to be fixed up a little, but I wouldn't waste the tsunami's efforts, rather route the road around it and turn it into a spectacular tourist attraction. Japan is going to need tourist attractions ...

It would have to be removed, cleaned, drained and scrubbed first, then replaced. Knowing the Japanese I'd suspect something made from a ship, not a whole ship itself. One is a reminder, the latter is a momument.
 
  • #35
davenn said:
That really shows his lack of understanding of megathrust systems and their potentials !

..."This area has a long history of earthquakes, but [the Sendai earthquake] doesn’t fit the pattern,” says Harold Tobin, a marine geophysicist at the University of Wisconsin–Madison. “The expectation was high for a 7.5, but that’s a hundred times smaller than a 9.0.”

that almost makes me laugh. Wonder what sort of marine geophysicist he is ? maybe he doesn't specialise in plate tectonics ?
Any, I repeat ANY major thrust system is capable of producing such events, That is just a given especially when you look back in history at the different regions around the Pacific and Indian Oceans.

Cheers
Dave

I don't have any background in megathrust earthquakes, and it made me laugh too.

The USGS has just posted an interesting bit regarding the quake:
http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0001xgp/#summary" [Broken]
...
The location, depth, and focal mechanism of the March 11 earthquake are consistent with the event having occurred on the subduction zone plate boundary. Modeling of the rupture of this earthquake indicate that the fault moved upwards of 30-40 m, and slipped over an area approximately 300 km long (along-strike) by 150 km wide (in the down-dip direction). The rupture zone is roughly centered on the earthquake epicenter along-strike, while peak slips were up-dip of the hypocenter, towards the Japan Trench axis.

...

Beyond the ongoing aftershock sequence, the USGS does not believe that the earthquakes in Japan have significantly raised the probability of future major earthquakes. While the probability of future large earthquakes far from northern Honshu has not increased, neither has it decreased and large earthquakes will continue to occur just as we have observed in the past.

Page Last Modified: March 19, 2011 21:31:33 UTC
bolding mine

What would happen if a fault were to shift by 1 or 2 hundred meters, instead of just 30 or 40? Giga-Tsunami?
 
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<h2>1. How strong was the Japanese earthquake?</h2><p>The Japanese earthquake, also known as the Great East Japan Earthquake, had a magnitude of 9.0 on the Richter scale. This makes it one of the strongest earthquakes ever recorded in Japan.</p><h2>2. How many people were affected by the earthquake?</h2><p>The Japanese earthquake affected millions of people, with a total of 15,896 people confirmed dead and over 2,500 people still missing as of 2020. Additionally, over 400,000 people were displaced from their homes and many more were left without access to basic necessities.</p><h2>3. What caused the Japanese earthquake?</h2><p>The Japanese earthquake was caused by the movement of tectonic plates beneath the Earth's surface. Japan sits on the Pacific Ring of Fire, an area prone to seismic activity due to the collision of several tectonic plates. This movement caused a rupture in the Earth's crust, resulting in the earthquake.</p><h2>4. How did the Japanese government respond to the earthquake?</h2><p>The Japanese government responded quickly to the earthquake, mobilizing emergency services and setting up shelters for those affected. They also implemented strict building codes and disaster preparedness measures in the years following the earthquake to better prepare for future disasters.</p><h2>5. Will there be more earthquakes in Japan in the future?</h2><p>Due to its location on the Pacific Ring of Fire, Japan is prone to earthquakes and other natural disasters. While it is impossible to predict exactly when and where earthquakes will occur, it is likely that Japan will experience more earthquakes in the future. However, the Japanese government and its citizens are continuously working to improve disaster preparedness and response to minimize the impact of future earthquakes.</p>

1. How strong was the Japanese earthquake?

The Japanese earthquake, also known as the Great East Japan Earthquake, had a magnitude of 9.0 on the Richter scale. This makes it one of the strongest earthquakes ever recorded in Japan.

2. How many people were affected by the earthquake?

The Japanese earthquake affected millions of people, with a total of 15,896 people confirmed dead and over 2,500 people still missing as of 2020. Additionally, over 400,000 people were displaced from their homes and many more were left without access to basic necessities.

3. What caused the Japanese earthquake?

The Japanese earthquake was caused by the movement of tectonic plates beneath the Earth's surface. Japan sits on the Pacific Ring of Fire, an area prone to seismic activity due to the collision of several tectonic plates. This movement caused a rupture in the Earth's crust, resulting in the earthquake.

4. How did the Japanese government respond to the earthquake?

The Japanese government responded quickly to the earthquake, mobilizing emergency services and setting up shelters for those affected. They also implemented strict building codes and disaster preparedness measures in the years following the earthquake to better prepare for future disasters.

5. Will there be more earthquakes in Japan in the future?

Due to its location on the Pacific Ring of Fire, Japan is prone to earthquakes and other natural disasters. While it is impossible to predict exactly when and where earthquakes will occur, it is likely that Japan will experience more earthquakes in the future. However, the Japanese government and its citizens are continuously working to improve disaster preparedness and response to minimize the impact of future earthquakes.

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