Powerful quake strikes off Japan; no tsunami warning

[Omaha Steve]

Source: AP

TOKYO (AP) — A powerful but extremely deep earthquake has struck off Japan's Ogasawara islands, but officials say there is no danger of a tsunami.

Japan's Meteorological Agency says the offshore earthquake struck Saturday at 8:24 p.m. at a depth of 590 kilometers (370 miles). The U.S. Geological Survey says the quake had a magnitude of 7.8 and a depth of 678 kilometers (421 miles).

Public broadcaster NHK said there were no immediate reports of injuries or damage.

The meteorological agency did not issue a tsunami warning because the quake struck so far beneath the earth's surface.

FULL short breaking story at link.

Read more: http://bigstory.ap.org/article/a380d0c1fccd420a9d76b87ff83f74a2/powerful-quake-strikes-japan-no-tsunami-warning

[DhhD]

1. Deep Ocean Assessment

http://www.ndbc.noaa.gov/dart/dart.shtml

[DhhD]

7. Water height information and other buoy station data helps determine a tsunami forecast.

http://www.ndbc.noaa.gov/

[Art_from_Ark]

2. That sucker was felt throughout most of Japan

I felt it, too. There was a small quake just before that, and then came the bigger one, and it seemed to keep going and going and I thought, "Oh crap, another Big One"

[dixiegrrrrl]

4. Now news says 8.5

Which is unimaginable to me, who has been thru a couple of "severe " ones of lesser magnitude.

Any damage reports?????

[Art_from_Ark]

6. The strongest intensity on the Japanese scale is being reported as a 5+

(or "5-upper&quot . Here's an explanation of what that means (scroll about halfway down the page)

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

[suffragette]

10. Sounds like a scary one

Glad to see you posting and hope all is ok.

[Art_from_Ark]

11. Thanks for your kind words

All is OK, but we seem to be having a rash of earthquakes, and they have had different epicenters, and it's getting a bit disconcerting. Just today, there were 3 earthquakes that I felt-one was early this morning, centered near my town, one was a small quake that was centered a bit north of me, and then there was that big sucker which was centered hundreds of miles offshore.

[suffragette]

12. Ring of fire seems pretty restless

Were the earthquakes similar feeling or different?
Jerky vs rolling?

It is nerve racking when you have clusters like that.
Always wondering if get are pre-shock, after shock or main strike.
I hope it settles down.

[Art_from_Ark]

13. The earthquake we had on Thursday morning was jerky

It instantly knocked some little things off my shelves. The earthquake we had this morning was sort of a combination of jerky and rolling, and the big one tonight was rolling.

[suffragette]

14. The jerky ones always make me more nervous.

But the magnitude of the deep roller is scary.

Hope they got it out of their system and it quiets down there.

[Art_from_Ark]

15. All the recent activity gets a little disconcerting

There was a 6.5 on May 13 that was close to the epicenter of the 2011 megaquake. Both were caused by subduction between the North American Plate and the Pacific Ocean Plate. Tonight's quake seems to have been caused by subduction between the Pacific Ocean Plate and the Philippine Sea Plate. There's also the Eurasian Plate that we have to contend with.

[suffragette]

18. It's only a matter of time before the subduction plate here causes a big one.

Hope things have been calmer there today for you.

[Art_from_Ark]

19. Yesterday was pretty quiet around here

I hope it stays that way.

And I hope you never have to experience a "Big One" over there

[Art_from_Ark]

3. The Japan Meteorological Agency is saying that the magnitude was 8.5

http://www.jma.go.jp/jp/quake/

[dixiegrrrrl]

5. in reading that same report, I see that

different stations report they felt much lower magnitudes....
which is lucky, I guess.

Maybe that decision to restart some nuclear plants over there needs to be re-thought, tho????

[Art_from_Ark]

8. Japan distinguishes between magnitude and seismic intensity

Magnitude is the force at the epicenter, while seismic intensity quantifies how it feels and what kinds of damage it could cause in local areas. So on the Japanese scale, 4 is a little scary, while anything 5 or above is cause for concern.

[dixiegrrrrl]

9. ty for that info.......

[uppityperson]

16. Thanks for all your input and it sounds scary.

Glad you are ok, there wasn't the damage this time, if I am reading it right.

[Art_from_Ark]

17. There might have been damage, like inside people's homes in "Intensity 5" areas

I think that shelved goods in a few stores in the strongest intensity areas might have been damaged as well. That's usually the case with a "5-upper" intensity.