Giant Tidal Wave in Thailand.....

Karl Denninger wrote:

>
>
>
> The problem is not really the height - its that they can be 100 miles WIDE.

It is the speed.
Tsunami waves are triggered by movements of the seabed, opposed to wind
normal driven waves.

Thus the normal math to calculate wave height/Speed/ wind/sea depth do
not apply.
Tsunamis can travel with several hundreds mph speed.

You can simulate it in your batthub. Test the difference between blowing
at the surface, and letting bounce your belly.

Matthias

Randy Buckner <Randybuckner@nospamaol.com> wrote:
>> ? So what's a 5-6m tsunami wave like compared to a regular one? And is it
>> ? a one shot deal, or does it come in a set?
>> ?
>> ? For one of the largest earthquakes ever, I guess I thought it would be
>> much bigger.
>>
>> Large is relative. A 20' wave still isn't trivial.
>>
>To say the least, Alan. I do not know the physics of wave energy, but I
>remember reading that a 4' wave on one mile of coast generates 35,000 hp of
>energy. I'm sure that is logarithmic with a 20' wave.

but I'm not so concerned with the energy of a 4' wave over a mile of coast.
Ocean Beach just down the road from me has surfing ranging from nothing to
double overheaders. And occasionally bigger waves that aren't surfed. A storm
can give us 20'ers for a while. Doesn't harm things a bit...the coast is forged
by this range. Personally I've been out in up to 10s, though usually not
intentionally about 6-7.

This one wiped out beach resorts, so obviously it's more than that.

--
Jason O'Rourke www.jor.com

In article <cqnm9a$1nth$1@agate.berkeley.edu>,
jor@soda.csua.berkeley.edu (Jason O'Rourke) wrote:

> Alan Street <agstreet@nonono_san.rr.com> wrote:
> >Tidal waves as high as five metres hit Penang and several other
> >Malaysian islands following the 8.9-magnitude earthquake near
> >Indonesia's Sumatra island.
>
> So what's a 5-6m tsunami wave like compared to a regular one? And is it
> a one shot deal, or does it come in a set?

Its a series.

As the ground shakes, it causes some up and down 'piston' action that
make some waves, and then when the ground finally shifts, think of this
as the 'piston' getting stuck in the up position, which forces the
displacement of a big bubble of water.

The danger is not just the 'wave', but the total mass which acts in a
fashion similar to a Hurricane's Storm Surge.

FWIW, for this event, the biggest wave was reportedly not the first
one. It appears that the 2nd or 3rd wave was the strongest, as per
eyewitness statements.


> For one of the largest earthquakes ever, I guess I thought it would
> be much bigger.


The biggest waves reported from this Tsnunami were reported at 20m,
although I'm not sure which country these hit. Wave height can depend
on local topology forming factors.

Finally, when it comes to power, the rule of thumb is a square
relationship: doubling a wave's height means it has 4x the energy.
Thus, a 20m wave has ~~64 times the energy of a (2.5m) 8 foot wave.



-hh

Matthias Voss wrote:

> Karl Denninger wrote:
>
>>
>>
>>
>> The problem is not really the height - its that they can be 100 miles
>> WIDE.
>
>
> It is the speed.
> Tsunami waves are triggered by movements of the seabed, opposed to wind
> normal driven waves.
>
> Thus the normal math to calculate wave height/Speed/ wind/sea depth do
> not apply.
> Tsunamis can travel with several hundreds mph speed.
>
> You can simulate it in your batthub. Test the difference between blowing
> at the surface, and letting bounce your belly.
>
> Matthias
>

The water would have to be awfully deep to get my belly to bounce in the
water!

>> ? >Tidal waves as high as five metres hit Penang and several other
>> ? >Malaysian islands following the 8.9-magnitude earthquake near
>> ? >Indonesia's Sumatra island.
>> ?
>> ? So what's a 5-6m tsunami wave like compared to a regular one? And is
>> it
>> ? a one shot deal, or does it come in a set?
>> ?
>> ? For one of the largest earthquakes ever, I guess I thought it would be
>> much bigger.
>>
>> Large is relative. A 20' wave still isn't trivial.
>>
> To say the least, Alan. I do not know the physics of wave energy, but I
> remember reading that a 4' wave on one mile of coast generates 35,000 hp
> of energy. I'm sure that is logarithmic with a 20' wave.

Since we know of the deaths and devastation caused by these waves, it's easy
to say that they are not trivial. On the other hand, we've all seen
pictures of people surfing on waves of comparable height. It's not clear
why a Tsunami is so different, but it's apparent that they were.

Lee

H. Huntzinger wrote:

> In article <cqnm9a$1nth$1@agate.berkeley.edu>,
> jor@soda.csua.berkeley.edu (Jason O'Rourke) wrote:
>
>
>>Alan Street <agstreet@nonono_san.rr.com> wrote:
>>
>>>Tidal waves as high as five metres hit Penang and several other
>>>Malaysian islands following the 8.9-magnitude earthquake near
>>>Indonesia's Sumatra island.
>>

How much time passed from the earthquake to the Tsunami? You would
think that they knew it was coming from aerial surveillance of the area.
Does/Can a tsunami be generated from the epicenter or miles away or
just anywhere in the general area?

Do they know where the Tsunami was generated, one report I read or heard
said the Tsunami was traveling at 500 mph, I hate to try to out swim that!

Wasn't Mossman going to Thailand to dive over XMAS? Does anyone
remember or know?

Lee Bell wrote:
>>>? >Tidal waves as high as five metres hit Penang and several other
>>>? >Malaysian islands following the 8.9-magnitude earthquake near
>>>? >Indonesia's Sumatra island.
>>>?
>>>? So what's a 5-6m tsunami wave like compared to a regular one? And is
>>>it
>>>? a one shot deal, or does it come in a set?
>>>?
>>>? For one of the largest earthquakes ever, I guess I thought it would be
>>>much bigger.
>>>
>>>Large is relative. A 20' wave still isn't trivial.
>>>
>>
>>To say the least, Alan. I do not know the physics of wave energy, but I
>>remember reading that a 4' wave on one mile of coast generates 35,000 hp
>>of energy. I'm sure that is logarithmic with a 20' wave.
>
>
> Since we know of the deaths and devastation caused by these waves, it's easy
> to say that they are not trivial. On the other hand, we've all seen
> pictures of people surfing on waves of comparable height. It's not clear
> why a Tsunami is so different, but it's apparent that they were.
>
> Lee
>
>
It is probably much like the difference in 80 mph winds and 80 mph winds
in a tornado - the concentration, and speed of the massive wave of
water. Don't know if the wind analogy is very good. Tsunamis are not
just immense in height, but in all dimensions with the element of water
moving at 500 mph.

I am sure in the next several days we will get a much better
understanding of the force.

Joe English wrote:
> H. Huntzinger wrote:
>
>> In article <cqnm9a$1nth$1@agate.berkeley.edu>,
>> jor@soda.csua.berkeley.edu (Jason O'Rourke) wrote:
>>
>>
>>> Alan Street <agstreet@nonono_san.rr.com> wrote:
>>>
>>>> Tidal waves as high as five metres hit Penang and several other
>>>> Malaysian islands following the 8.9-magnitude earthquake near
>>>> Indonesia's Sumatra island.
>>>
>>>
>
> How much time passed from the earthquake to the Tsunami? You would
> think that they knew it was coming from aerial surveillance of the area.
> Does/Can a tsunami be generated from the epicenter or miles away or
> just anywhere in the general area?
>
> Do they know where the Tsunami was generated, one report I read or heard
> said the Tsunami was traveling at 500 mph, I hate to try to out swim that!
>
> Wasn't Mossman going to Thailand to dive over XMAS? Does anyone
> remember or know?

They move at 500mph in deep water but are very small. As the water
shallows the wave slows and the volume of moving water piles up so you
get a big wave, it is not moving that fast though. The overall volume
of water is not just the breaking wave but the whole mass of moving
water following, I believe this is the difference when compared to large
surf type waves - it just keeps coming.

To all who are concerned about the passengers, crew and staff of Ocean Rover
Dive Cruises. . At the time of the disaster the boat was, and continues to
be, in Myanmar Mergui Archipelago which was unaffected by the tidal waves.

Management is in continuous contact with the boat via satellite phone. The
office and office infrastructure is intact. Communications in Phuket are
very limited at this time. Updates will be posted if necessary.

Diving in Myanmar is good and he boat has been unaffected by the disaster.

John


"KT" <kt_91488044@yahoo.com.hk> wrote in message
news:cqmdg5$qvs2@imsp212.netvigator.com...
> http://www.turkishpress.com/world/ne...8.eimrlc5x.xml
>
> Anyone knows how the situation is at Phuket, Kao Lak & Similan Island?
>
>
>

On Mon, 27 Dec 2004 14:08:41 GMT, "Lee Bell"
<leebell@ix.remove.netcom.com> wrote:

>>> Large is relative. A 20' wave still isn't trivial.
>>>
>> To say the least, Alan. I do not know the physics of wave energy, but I
>> remember reading that a 4' wave on one mile of coast generates 35,000 hp
>> of energy. I'm sure that is logarithmic with a 20' wave.
>
>Since we know of the deaths and devastation caused by these waves, it's easy
>to say that they are not trivial. On the other hand, we've all seen
>pictures of people surfing on waves of comparable height. It's not clear
>why a Tsunami is so different, but it's apparent that they were.

OK.

Normal waves:

------/\---/\---/\----

Go up, down, up, down - individual waves may be (say) 20' from crest
to trough and 50' long from one crest to the next.

Tsunami:

--------- (a mile or more) --------
/ \
-------- -------------

It's not really a 'wave' at all, as we normally think of waves - it's
a huge mass of displaced water. It's much more like the storm surge
beneath the eye of a hurricane, to give a more familiar example, which
is when the surface of the ocean is 'sucked up' by the low pressure in
the eye. Except the tsunami is much worse, as it arrives all at once,
not gradually building up over hours like an approaching hurricane.

Think 'instant temporary global warming raising water level by 20' or
more'.

Mike
--
http://www.corestore.org
"All I know is that I'm being sued for unfair business practices by Microsoft. Hello pot? It's kettle on line two" -
Michael Robertson