ANOTHER BIG ONE...7.8 QUAKE

[Janice]

Just like when and if SanFrancisco gets hit with the BIG one. How much warning will people get? Enough to get everyone out. Nature does not have to tell us a thing. We learned that the hard way.

[Janice]

I have a question. They said that the 2004 tsunami was way bigger. What is the minimum quake ever recorded that produced a tsunami? Does it have to be over 7.5, etc. or can a small quake produce one?

[Janice]

CNN just said that the islands and Fiji are reporting they have not felt anything so far.

[feederband]

I have a question. They said that the 2004 tsunami was way bigger. What is the minimum quake ever recorded that produced a tsunami? Does it have to be over 7.5, etc. or can a small quake produce one?

It all depends on the type of quake..How deep...etc.

[Thierry_Gironde]

I'm not sure about what the smallest magnitude tsunami-producer was...but in terms of earthquake generated tsunamis, the size of the wave is dependent upon how much water is displaced. A general, I think it's called a strike-slip earthquake, which moves horizontally (rough terms) does not produce one in itself; instead, a thrust/mega-thrust earthquake can produce a tsunami by displacing the water above it. With this in mind, it seems that there would have to be a lower limit; that is, if you have a 3.0 thrust earthquake, how much water could be vertically displaced by that?

Bad explanation, and inaccurate, I'm sure. But it should give you a rough idea.

[feederband]

So far so good...

[Janice]

Someone just called in to CNN from those islands and she said no one was warning anyone. She turned on CNN and heard it from her tv. She said everyone is asleep or getting up and unaware of what is going on.

[GalvestonDuck]

Ugh, not good...patiently waiting.

<---ROC lives in New Zealand.

[feederband]

Bouy had a lift of 40 inch....Don't know what that means...CNN

[feederband]

Person in Tonga talking on CNN..

[Janice]

If you want to come to the chatroom, we can discuss all this.

[angelwing]

Wish I could, work blocks out the chatroom

[MiamiensisWx]

I'm there now!

[GalvestonDuck]

Ditto on no chat -- just refreshing this page (since news websites aren't always updated as often as forums) and hoping for good news.

[feederband]

Quake lasted for 4 minutes...

According to guy talking on CNN

[furluvcats]

That seems like a long quake...the ones I have experienced seem to have come and gone quicker than a minute...

[feederband]

That seems like a long quake...the ones I have experienced seem to have come and gone quicker than a minute...

I bet some of those islands are a wreck..

[therock1811]

Warning has been cancelled now for the Pacific.

TSUNAMI BULLETIN NUMBER 003
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 1736Z 03 MAY 2006

THIS BULLETIN IS FOR ALL AREAS OF THE PACIFIC BASIN EXCEPT
ALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.

... TSUNAMI WARNING CANCELLATION ...

THE TSUNAMI WARNING IS CANCELLED FOR ALL COASTAL AREAS AND ISLANDS
IN THE PACIFIC OUTSIDE OF ALASKA - BRITISH COLOMBIA - WASHINGTON -
OREGON - CALIFORNIA. THOSE AREAS SHOULD REFER TO MESSAGES FROM THE
WEST COAST AND ALASKA TSUNAMI WARNING CENTER.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME - 1527Z 03 MAY 2006
COORDINATES - 19.9 SOUTH 174.2 WEST
LOCATION - TONGA ISLANDS
MAGNITUDE - 7.8

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION LAT LON TIME AMPL PER
------------------- ----- ------ ----- ------ -----
PAGO PAGO 14.3S 170.7W 1636Z 0.15M 24MIN
NIUE 19.1S 169.9W 1603Z 0.21M 10MIN

TIME - TIME OF THE MEASUREMENT
AMPL - AMPLITUDE IN METERS FROM MIDDLE TO CREST OR MIDDLE
TO TROUGH OR HALF OF THE CREST TO TROUGH
PER - PERIOD OF TIME FROM ONE WAVE CREST TO THE NEXT

EVALUATION

SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY HAVE
BEEN DESTRUCTIVE ALONG COASTS NEAR THE EARTHQUAKE EPICENTER. FOR
THOSE AREAS - WHEN NO MAJOR WAVES ARE OBSERVED FOR TWO HOURS
AFTER THE ESTIMATED TIME OF ARRIVAL OR DAMAGING WAVES HAVE NOT
OCCURRED FOR AT LEAST TWO HOURS THEN LOCAL AUTHORITIES CAN ASSUME
THE THREAT IS PASSED. DANGER TO BOATS AND COASTAL STRUCTURES CAN
CONTINUE FOR SEVERAL HOURS DUE TO RAPID CURRENTS. AS LOCAL
CONDITIONS CAN CAUSE A WIDE VARIATION IN TSUNAMI WAVE ACTION THE
ALL CLEAR DETERMINATION MUST BE MADE BY LOCAL AUTHORITIES.

NO TSUNAMI THREAT EXISTS FOR OTHER COASTAL AREAS IN THE PACIFIC
ALTHOUGH SOME OTHER AREAS MAY EXPERIENCE SMALL SEA LEVEL CHANGES.
THE TSUNAMI WARNING IS CANCELLED.

THIS WILL BE THE FINAL BULLETIN ISSUED FOR THIS EVENT UNLESS
ADDITIONAL INFORMATION BECOMES AVAILABLE.

THE WEST COAST/ALASKA TSUNAMI WARNING CENTER WILL ISSUE BULLETINS
FOR ALASKA - BRITISH COLUMBIA - WASHINGTON - OREGON - CALIFORNIA.

[feederband]

Cool..Although maybe not cool to the islands that were close..

[Brent]

Quake lasted for 4 minutes...

According to guy talking on CNN

The 2004 Indian Ocean quake lasted up to 10 minutes.

This earthquake was also reported to be the longest duration of faulting ever observed, lasting between 500 and 600 seconds.

http://en.wikipedia.org/wiki/2004_India ... earthquake