Merged 8.8 quake in Sendai, Japan

[Rolfe]

Here's the video showing the Rikuzentakata flood gate. The wall beside it looks massive, but I think I can see sky at one point where wall should be.

http://www.bbc.co.uk/news/world-asia-pacific-12801085

Here's the one with the Taro gate. Go to about 4 minutes. Not sure if this is a permanent link, or if it is universally viewable. This looks like an overtopped wall intact but for the busted-out gate.

http://www.channel4.com/news/catch-up/display/playlistref/210311/clipid/210311_thomo_21

Rolfe.

 

[rjh01]

Just passing. There has been a SWIFT article on the earthquake here
http://www.randi.org/site/index.php...on-doesnt-get-you-the-pseudoscience-will.html

Now carry on as usual.

 

[BeAChooser]

The entire coastline could have been designed to be a tsunami death trap.

Yes, the topography of the Japanese coastline seems particularly susceptible to tsunami.

 

[BenBurch]

The barrier at face value would appear to be high enough to withstand the tsunami that hit Japan, but it's only 500 metres in length. I can't see anything similar being constructed except to protect another major capital city.

If a Tsunami barrier will not stop a Tsunami, what is the value of having it?

 

[Rolfe]

How big is a tsunami? How long is a piece of string? You take your best guess at how high your worst-case scenario wave will go.

This one was bigger.

Rolfe.

 

[jimbob]

Will they really decide to abandon the flat ground at the head of all these picturesque coves and not build on it again? What about all the similar towns in the same vulnerable location that just didn't get hit this time?

Rolfe.

I had always heard that the Japanese tended to build on the flatter land because of the earthquake risk.

This surprised me when visiting my kiwi friends in Wellington, who also mentioned this, given how geologically active New Zealand is, and the slopes that are built on (in a country that has significantly less population pressure to put it mildly).

On a secondary point that has been raised before about construction techniques, and the traditional Japanese paractice of building in wood not masonary, wiki states the following:

http://en.wikipedia.org/wiki/Earthquakes_in_New_Zealand#Building_regulations

Building regulations This section requires expansion.


Early settlers learned fairly quickly the importance of using appropriate building methods in an earthquake-prone country. The 1848 earthquake, centred in Marlborough, caused great damage to the brick and masonry buildings in Wellington, and the city was rebuilt mainly in wood; consequently it suffered comparatively little damage in the 8.2 magnitude earthquake of 1855, which lifted the land 2–3m.[8]

 

[Hindmost]

If you remove the fuel rods, what's the point of burying it?

Glenn?

If they could get all the fuel out, there would be no need for the concrete grave. There would still be a bunch of contamination in all the structure, but that can be cleaned up to a point where they could dismantle the plant and bury it in a nuke grave yard.

Getting the fuel out will be difficult as it will be in various stages of disrepair: some will be OK and not leaking, some will have blisters/leaking and some is going to be broken in a piles at the bottom of the spent fuel pool or vessel. Once cooling is established and reliable, they will have to look at how to make special tools to get all the fuel into containers that can store it for extended periods and also shield the high levels of radiation. It will be a pain and very expensive.

glenn

 

[elgarak]

If they could get all the fuel out, there would be no need for the concrete grave. There would still be a bunch of contamination in all the structure, but that can be cleaned up to a point where they could dismantle the plant and bury it in a nuke grave yard.

Getting the fuel out will be difficult as it will be in various stages of disrepair: some will be OK and not leaking, some will have blisters/leaking and some is going to be broken in a piles at the bottom of the spent fuel pool or vessel. Once cooling is established and reliable, they will have to look at how to make special tools to get all the fuel into containers that can store it for extended periods and also shield the high levels of radiation. It will be a pain and very expensive.

glenn

And it will take a long, long time.

 

[Rolfe]

I had always heard that the Japanese tended to build on the flatter land because of the earthquake risk.

This surprised me when visiting my kiwi friends in Wellington, who also mentioned this, given how geologically active New Zealand is, and the slopes that are built on (in a country that has significantly less population pressure to put it mildly).

On a secondary point that has been raised before about construction techniques, and the traditional Japanese paractice of building in wood not masonary, wiki states the following:

http://en.wikipedia.org/wiki/Earthquakes_in_New_Zealand#Building_regulations

It's back to something Soapy Sam said earlier, that building to withstand an earthquake and building to withstand a tsunami have significantly different parameters.

If tsunamis of this magnitude are one every several hundred years, they may well simply take the risk on the basis of "it won't happen to us".

Rolfe.

 

[Puppycow]

I was reading the paper at lunchtime and noticed a very different snippet from Rikuzentakata.




That's a lot closer to the official figures (scaled down to town level) and very much below the unofficial estimates coming out of the town last week. It suggests a high percentage of the "missing" have actually showed up. It's still a 10% fatality rate, but when they were talking about half the town at one stage, it's encouraging. And that's the place where the floodgates didn't shut and the tsunami shelters were below the level the tsunami reached.

Rolfe.

Hmm. Have they said how many residents have been accounted for though? At one point several days after the earhtquake I read that about 6800 residents of Rikuzentakata were at evacuation centers. If only about 2400 are 'officially' missing or dead, where are all the others? Were there any parts of the town that survived?

ETA: Maybe they left the area to stay with relatives or friends.

 

[Rolfe]

I don't know. The reports are quite conflicting. But certainly, it would make absolute sense that anyone who could go to stay with friends would do that rather than stay on in the school classrooms. Now, though, people are coming back to these towns to see if they can salvage any personal possessions before the bulldozers move in, so perhaps the lists are being updated that way.

Most of these towns are surrounded by wooded hills, and several of the tsunami videos have been taken from these vantage points. Rikuzentakata is particularly well-supplied with these hills, which reach into the built-up area like fingers.

http://maps.google.co.uk/maps?hl=en...39.00930409,141.6385642,5495.64,-0.006,6.17,0

The famous video of the tsunami hitting the town, the first one that made the outside news broadcasts, was shot from the most prominent of these hills. Looking at the lie of the land, and given that there was at least 15 minutes warning, I wonder if far more people than was initially realised got to a hilly area.

As an aside, I can't see where the tsunami barrier was in the river, on that Google Earth view.

Rolfe.

 

[Skeptic Ginger]

If they could get all the fuel out, there would be no need for the concrete grave. There would still be a bunch of contamination in all the structure, but that can be cleaned up to a point where they could dismantle the plant and bury it in a nuke grave yard.

Getting the fuel out will be difficult as it will be in various stages of disrepair: some will be OK and not leaking, some will have blisters/leaking and some is going to be broken in a piles at the bottom of the spent fuel pool or vessel. Once cooling is established and reliable, they will have to look at how to make special tools to get all the fuel into containers that can store it for extended periods and also shield the high levels of radiation. It will be a pain and very expensive.

glenn

If you could just encase spent fuel rods in concrete we wouldn't have the problem we have now with nuclear waste disposal. I don't think using the 'Chernobyl' solution does more than make it harder to deal with later.

 

[Hindmost]

If you could just encase spent fuel rods in concrete we wouldn't have the problem we have now with nuclear waste disposal. I don't think using the 'Chernobyl' solution does more than make it harder to deal with later.

I agree Chernobyl is not a good solution as it does push the problem off to a future date. I don't think it will be culturally acceptable to Japan anyhow. Normal spent fuel can be stored in dry concrete casks after it has been out of the reactor for long enough. Some of the spent fuel here will still require cooling for a significant period.

http://en.wikipedia.org/wiki/Dry_cask_storage

glenn

 

[Rolfe]

A charity news update from yesterday has stated that 80% of the houses in Rikuzentakata were swept away, which is pretty bad. It doesn't say anything about casualties though. It does look as if everywhere except the main town centre by the sea front was within very easy reach of the surrounding hills. These would have been much safer refuges than buildings that weren't high enough, or were themselves vulnerable to being swept away.

Rolfe.

 

[Rolfe]

National Geophysical dataset for the tsunami

Here are the statistics for towns and villages affected, with maximum water heights, death tolls and property damage.

http://www.ngdc.noaa.gov/nndc/struts/results?EQ_0=5413&t=101650&s=9&d=92,183&nd=display

The worst death toll is in Ishinomaki, with 1,826 deaths confirmed. Having said that, the population of that city/area is given as about 165,000. Rikuzen(takata), in second place, is listed as having 741 confirmed deaths out of a population of only about 24,000.

The data are still quite patchy and in the process of compilation though. No doubt all figures are subject to change.

Rolfe.

 

[DC]

Here are the statistics for towns and villages affected, with maximum water heights, death tolls and property damage.

http://www.ngdc.noaa.gov/nndc/struts/results?EQ_0=5413&t=101650&s=9&d=92,183&nd=display

The worst death toll is in Ishinomaki, with 1,826 deaths confirmed. Having said that, the population of that city/area is given as about 165,000. Rikuzen(takata), in second place, is listed as having 741 confirmed deaths out of a population of only about 24,000.

The data are still quite patchy and in the process of compilation though. No doubt all figures are subject to change.

Rolfe.

very depressing

 

[Rolfe]

Indeed. But in the context of the population sizes, probably a lot less than it might have been. The tsunami warning sirens must have saved many thousands.

Rolfe.

 

[Puppycow]

This news is bound to cause a lot of apprehension even if the actual risk is small:

http://search.japantimes.co.jp/cgi-bin/nn20110323x2.html

 

[babycondor]

On contaminated food bans:

Edano, however, said that even if someone were to eat radioactive kukitachina [a vegetable] for 10 days in a row, the total amount of radioactive material consumed would be half of what a person is exposed to in the natural environment in a year and would pose no future health risks.

I understand they are trying to minimize panic. But they don't talk about cumulative effects of radiation in many other things besides the vegetables, and the "natural environment" is misleading too. The natural environment has been contaminated. Background radiation has increased significantly, especially near the nuclear plants. So yes, eating this one vegetable for 10 days may be fine, but what about adding up all the other radiation people are exposed to?

In other forums I have seen people say things like "aside from Chernobyl, how many deaths can be blamed on nuclear accidents?" or "ignoring the cooling pond issue which IS a weakness...." No, let's not brush aside Chernobyl or ignore the cooling pond issues, please. A balanced approach to meeting our energy needs should take all risk factors into account and weight them against the benefits.

 

[zooterkin]

On contaminated food bans:



I understand they are trying to minimize panic. But they don't talk about cumulative effects of radiation in many other things besides the vegetables, and the "natural environment" is misleading too. The natural environment has been contaminated. Background radiation has increased significantly, especially near the nuclear plants. So yes, eating this one vegetable for 10 days may be fine, but what about adding up all the other radiation people are exposed to?

In other forums I have seen people say things like "aside from Chernobyl, how many deaths can be blamed on nuclear accidents?" or "ignoring the cooling pond issue which IS a weakness...." No, let's not brush aside Chernobyl or ignore the cooling pond issues, please. A balanced approach to meeting our energy needs should take all risk factors into account and weight them against the benefits.

The latest edition of the BBC Radio4 programme, Material World (available as a podcast) had a good look at the effects of radiation.