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8.9 earthquake in Japan: tsunami warnings

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Astronuc
#91
Mar11-11, 08:21 PM
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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
#92
Mar11-11, 08:36 PM
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We're going to have give our mister Elliot some hell for not properly tying up his submarine:

In Guam, the tsunami snapped mooring lines to two attack submarines, Houston and City of Corpus Christi. Tug boats immediately responded. “Both subs are safe and under the control of the tug boats,” Joint Region Marianas posted on its Facebook page. No injuries have been reported.
Good to hear that our subs are now under the control of tug boats.
lisab
#93
Mar11-11, 08:54 PM
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Quote Quote by OmCheeto View Post
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.
Oh dear. Don't they teach sailors the fine art of knot-tying anymore?
nismaratwork
#94
Mar11-11, 08:55 PM
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Quote Quote by lisab View Post
Oh dear. Don't they teach sailors the fine art of knot-tying anymore?
Nah, just boy scouts, and look at the state we're in now!
caffenta
#95
Mar11-11, 08:59 PM
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Quote Quote by Astronuc View Post
At 500 mph, the tsunami would hit the coast in about 15 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.
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
#96
Mar11-11, 09:00 PM
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Quote Quote by caffenta View Post
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
Yeah, unfortunately a lot of the flood waters are sticking around because of the terrain.
Astronuc
#97
Mar11-11, 09:24 PM
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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
#98
Mar11-11, 09:34 PM
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Quote Quote by Astronuc View Post
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.
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
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Mar12-11, 01:02 AM
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Quote Quote by DevilsAvocado View Post
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!
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
#100
Mar12-11, 01:19 AM
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Quote Quote by Ivan Seeking View Post
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.
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
#101
Mar12-11, 01:22 AM
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Quote Quote by caffenta View Post
Tell me that again when you're faced with an 8-meter wall of water.
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
#102
Mar12-11, 03:33 AM
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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.
hypatia
#103
Mar12-11, 04:17 AM
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And now a explosion at the damaged plant..this just keeps getting worse.
DevilsAvocado
#104
Mar12-11, 05:31 AM
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Too small:

Massive Explosion at Fukushima I Nuclear Power Plant





http://www.bbc.co.uk/news/world-asia-pacific-12720219

Japan's nuclear agency said on Saturday that radioactive caesium and iodine had been detected near the number one reactor of the Fukushima 1 plant.

The agency said this may indicate that containers of uranium fuel inside the reactor may have begun melting.
Astronuc
#105
Mar12-11, 06:39 AM
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There are conflicting reports:

Explosion did not occur at reactor: Japan spokesman
http://mdn.mainichi.jp/mdnnews/news/...dm073000c.html

vs

Explosion Destroys Walls of Japanese Nuclear Reactor Building, NHK Reports
http://www.bloomberg.com/news/2011-0...k-reports.html


http://www.world-nuclear-news.org/RS...s_1203111.html

It is certainly a very serious, even grave, situation. However, it is difficult, even impossible to give a reliable assessment based on the sketchy information available.
Lacy33
#106
Mar12-11, 07:10 AM
P: 335
Hi Astro,
So we are wondering here really, is it possible that it will be a Chernobyl type situation or as my husband thinks and hopes they build these plants differently now.
I think I understand him to say that. He worked on building one.
What I am asking specifically is it possible that we could have an event that big again?
And are any professionals going there to help keep Japan it safe?
And Astro why are you not over there now helping? Thank you
nismaratwork
#107
Mar12-11, 07:41 AM
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Quote Quote by Astronuc View Post
There are conflicting reports:

Explosion did not occur at reactor: Japan spokesman
http://mdn.mainichi.jp/mdnnews/news/...dm073000c.html

vs

Explosion Destroys Walls of Japanese Nuclear Reactor Building, NHK Reports
http://www.bloomberg.com/news/2011-0...k-reports.html


http://www.world-nuclear-news.org/RS...s_1203111.html

It is certainly a very serious, even grave, situation. However, it is difficult, even impossible to give a reliable assessment based on the sketchy information available.
It really does sound like it was a hydrogen explosion... the images show smoke rising, but mostly dirty steam. I'm... unclear that this is anything as serious as an exposed or melting core. Chan Dallas is reporting, "620 mREMS/Hour", which I certainly don't want a part of, but it's hardly going to make you... poop... the bed.

I'm buying 'hydrogen blast' without the fuel becoming exposed.
nismaratwork
#108
Mar12-11, 07:41 AM
P: 2,284
Oh, and 9,500 missing in Miyagi prefecture alone (CNN)


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