8.9 earthquake in Japan: tsunami warnings

Astronuc

I posted in a related thread in the Nuclear Engineering forum.

A Reuters article (and others) attributes a statement to METI that the pressure in Unit 1 (vessel?) has reached 2.1 times design. That's not good, but then I can't substantiate that with a reliable source. I don't know if it refers to the primary system or containment; the design pressure are very different.

A second unit (unit 2?) is also having pressure control problems. Again it's unsubstantiated with an official source.

Also, unit 1 is the oldest of the 6 units at the site; first criticality March 1971. Unit 2 is about three years younger (first criticality July 1974). Fourty years is the original design life of the unit, although lifetimes of units of that vintage are being extended to 60 years.

Plant means the whole site. Some plants may have a single unit, but many, perhaps most have two or more units (reactors, primary system and balance of plant (BOP)).

nismaratwork

I'm really impressed by what's being discussed on CNN right now... Cham Davis is being pretty clear about the best-worst case scenario, and talking about the fear aspect.

In addition he seems certain (no guarantee) that before power died they did manage to fully insert control rods... so the SCRAM did work, meltdown is not a happening thing. I don't know how others will cover this, or use it... venting into the atmosphere is going to scare people, but so far there is real moderation in tone at least in the presence of authority.

On the other hand, it seems clear that the Japanese people are going to be afraid and angry no matter how this plays out... and not just the Japanese. Everyone just goes to Chernobyl (mentally I hope) and 3 Mile Island... as though they were remotely on the same order of magnitude.

I'm concerned that when the experts are no longer being interviewed, the sound-bites will become means to scare people.

DevilsAvocado

Thanks Astronuc, I was thinking about possible 'pre-warnings'... on the site Latest Earthquakes M5.0+ in the World - Past 7 days it starts already on 2011/03/09 02:45:20 with a M7.2, and then there are twenty M5.0+ quakes near Honshu... before the M8.9...

DevilsAvocado

Surreal footage, just look at the wave in the beginning of the first video – the ship is completely disappearing in the wave trough! That wave must have been > 8 meters!

If "only" 300 people were killed in Sendai – it’s a miracle! The distance from the shore to the Sendai center is only 10 km, and they say on CNN that they had approx 10 min (some say 30?) to evacuate. 1+ million people evacuated in less than 30 min must be a MIRACLE!!

(zoom in on the map, there’s a lot of buildings near the shore...)

caffenta

There are always quakes in Japan. Continually. They never stop. It's nothing unusual.

This is 1924-2008 (from here)


Japan has an early warning system, but it's only a few seconds. They have a monitoring system in place to try to predict the big Tokai one, but nobody knows if it actually works.

Astronuc

Japan initiates emergency protocol after earthquake
http://www.neimagazine.com/story.asp...ryCode=2059127

Still lacking key details.


Regarding the tsunami from the mag 8.9 earthquake, using the following information

Sendai City, Miyagi Prefecture, Japan
38° 15' 17" N
140° 53' 5" E

Sendai, Japan
Region: Miyagi
Country: Japan
Latitude: 38.2547222
Longitude: 140.8847222


Mag 8.9 earthquake
Latitude: 38.322 N
Longitude: 142.369 E

and assuming that 1 degree longitude is ~95 km, then the quake was about 140 km from Sendai City center which is about 10 miles (16 km) inland from the coast.

At 500 mph (800 kmph), the tsunami would hit the coast in about 10 minutes. Not a lot to time to react if one was not listening to the radio. On the other hand, presumably folks felt that quake and they should have immediately headed inland - and not toward the coast or parallel with the coast. Just get to higher ground - of at least 10 m above sea level.

One can get a more accurate distance with a calculator.
http://www.nhc.noaa.gov/gccalc.shtml


BTW - there was a mag 6.8 this morning, 2011/03/12 01:47:16, lat: 37.588N, long: 142.682E at depth of 24.8 km OFF THE EAST COAST OF HONSHU, JAPAN.

OmCheeto

We're going to have give our mister Elliot some hell for not properly tying up his submarine:

Good to hear that our subs are now under the control of tug boats.

lisab

Oh dear. Don't they teach sailors the fine art of knot-tying anymore?

nismaratwork

Nah, just boy scouts, and look at the state we're in now!

caffenta

Warnings were issued immediately, not just by radio. But the problem is that the region is flat and there are not that many roads towards higher ground, and not everybody is in a car, or even has one (Sendai is not LA). The region is a real pain to navigate, even in a non-emergency situation. check here

nismaratwork

Yeah, unfortunately a lot of the flood waters are sticking around because of the terrain.

Astronuc

Unfortunately, they don't appear to have effective evacuation roots in that coastal area.

As for tsunami effects across the Pacific.

http://wcatwc.arh.noaa.gov/
http://wcatwc.arh.noaa.gov/2011/03/1...elhvpd9-22.htm

Crescent City, Ca has about 8 feet of water.

nismaratwork

It's a damned shame, but there's only so much you can do with 15 minutes and a LOT of flat farmland and vallys.

8 feet in CC, CA?! Jesus.

Ivan Seeking

Heck, I've Boogie Boarded a wave that big. It is more the length than the height of the wave that makes it so devestating.

The black wall of water scouring the countryside did appear to be about twenty-five or thirty feet in height. Simply unbelievable!

caffenta

Tell me that again when you're faced with an 8-meter wall of water. Here are actual observations, not just media-generated anectodes.

Ivan Seeking

What I said was true. I have faced an 8-meter wall of water on a Boogie Board [the ride of a lifetime too!]. And for hardcore surfers, that's just childsplay. At North Shore in Hawaii, everyone starts going home when the waves get that small!


That is not to take away from the devestating effects of the tsunami. As I said, it is the wavelength more than the amplitude that makes it so deadly.

Borek

I wonder... What was the tide level on US coast when the wave came? And what is the tide amplitude on the US coast?

What I am thinking about is that if the tsunami wave came during low water and wave height was comparable with the tide, it could be dangerous for those that ventured to the beach (fast changes) but relatively safe for infrastructure (water don't getting higher than it does on a daily basis). On the other hand combined wave would be really high, but as there are no reports about disastrous effects I guess it wasn't the case.