The (not-so) solid Earth

[Frank McCoy]

Feel free to quote. Just include proper accreditation.

It's amazing how much we as people ass-u-me the earth beneath us
is solid and will never move or even twitch. We build houses of
stone, one piled upon another, and expect the resulting stack to last
for hundreds of generations ... and often they do, if not torn down,
blown apart, or destroyed by fire, flood, or war.
We build railroad tracks, clear across two thousand miles of
country, where an extra inch of difference could spell instant
disaster for speeding trains going 50-60mph, without ever expecting
anything to change all along that route. Oh, it's true that we build
in certain "leeway" to allow for thermal expansion from temperature
extremes, wind and other effects on bridges and such ... But the
assumption is that the "real" distance between two towers on each side
of a gorge won't change more than a few fractions of an inch in
centuries.
The assumtion is that this world we live on is SOLID ... A "solid
block of rock". Yet we all really know better.
Far from the earth being solid, it's a semi-plastic surface with
semi-solid scum floating on a mainly liquid ball spinning lazily
through space. Yes, *liquid*. Go down a mere two or three miles, and
the pressure and heat grows intense enough that "solid" rock flows
like putty. Go down 40 miles or so, and the distinction between
"solid" and "liquid" materials matters only when contemplating diamond
crystals. The Earth however, is about 4,000 mile thick, or about 100
times that depth of sloshy liquid. Even cobalt steel in the interior
is quite liquid at that depth; though there's some indication at the
very center pressure forces some kind of true solidity to some parts
of the core. It's the very liquid nature of the core (I understand
anyway) that allows us to have a geomagnetic field ... what we use to
give us compass-directions. Without the core being liquid, the dynamo
that drives the Earth's magnetic field would stop.
The very roundness of the earth (or to be correct, its
oblateness) is determined by gravity and spin ... holding the Earth to
the balance of the two forces to a roundness within one part in 1000;
as few mountains indeed exceed 5 miles in height.
Since the Earth has internal heat (generated from the star-stuff
it's made of ... the remaining tiny bits of Uranium and other leftover
radioactive materials gathered in from star-shit in this neighborhood
when the Sun and planets formed about 4-5 billion years ago) that is
continuously generated, it keeps the interior liquid ... and drives
convection currents like a pot slowly simmering.
People talk about "plate tectonics" and the "conveyer belt" of
the oceans ... but all that is, is the veiw we get from the top. It's
just the slow roiling of an established pattern of heat circulation.
And the "solid" Earth we live on, that set on top of the whole
thing? That's the scum" that's been scraped off the top of the kettle
over billions of years ... the LIGHT shit that floated to the top and
wouldn't go back down with the good stuff. We live on the
"continents" ... The light scum floating on the surface of a liquid
planet. It SEEMS solid to us; but is anything but. Mountains build
and subside over millenia (which to the billions of years of the life
of the planet are tiny periods of time indeed). Oceans open and are
filled in. The scum rises and settles. As things get cold and snow
packs build to mountain heights (what we call "Ice ages") the
mountains themselves are pushed down into the liquid underneath ...
and then rebound when the ice-pack melts.
The scum on the surface is always moving, always jiggling, always
adjusting to the pressures of the moving liquid underneath ... and in
no way is truly stable. Bubbles pop. Mountains slide. Cracks
appear. Pressures build until the scum cracks.
Then we have mountains that blow their tops ... Small mountains,
like Mt. Saint Helens, Bigger ones like Tambora or Krakatoa, or
humongous ones like the one that produced the Yellowstone Caldera.
When things blow or jiggle really badly undersea, we get Tsunamis
or "Tidal Waves" from a few tens of feet high to close to a thousand
feet high. All caused by (comparitively) tiny slippages in the
"solid" earth beneath us. A small earthquake can cause a *big*
landslide under the sea; making a disaster of a wave out of all
(apparent) perportion to the actual quake itself. Around the world
today there are at least half a dozen *major* disasters waiting to
happen ... on the scale of a major meteorite strike on a large city
... and yet hardly anybody is watching. The disaster this week
(Mid-December 2004) in the Indian Ocean is just a *tiny* hint of the
things that could hit. Yet we pay more attention to the possibility
of a rock hitting us from space than we do to the more real threat of
a Tsunami completely wiping out the East coast of the USA, with no
warning at all to evacuate, when we COULD have relatively cheap
warning systems in place globally, like Japan, Alaska, and Hawaii have
done for most of the Pacific.
Why not? Because we *know* the earth is solid. It always has
been, and always will be.

Yeah ... right.
Harry Truman, living on Spirit Lake, said something like that, just
before St. Helens blew.

[Shagrat]

Post by Frank McCoy
We build railroad tracks, clear across two thousand miles of
country, where an extra inch of difference could spell instant
disaster for speeding trains going 50-60mph, without ever expecting
anything to change all along that route. Oh, it's true that we build
in certain "leeway" to allow for thermal expansion from temperature
extremes, wind and other effects on bridges and such ... But the
assumption is that the "real" distance between two towers on each side
of a gorge won't change more than a few fractions of an inch in
centuries.

Unless the gorge indicates a geological fault, the towers *won't* change
in centuries. Continents, with certain exceptions such as the rift valley
in Africa, sit atop single plates and their centres remain stable for tens
of millions of years.

Post by Frank McCoy
It's the very liquid nature of the core (I understand
anyway) that allows us to have a geomagnetic field ... what we use to
give us compass-directions. Without the core being liquid, the dynamo
that drives the Earth's magnetic field would stop.

A very neat point. Without the magnetic field, life would not be possible
at the Earth's surface. It isn't on Mars. Life would continue within the
earth itsel: there appears to be more biomass living in cracks underground
than on the entire surface but multicellular life is impossible there.
Oceanic life would also continue.

Your comment "(I understand anyway)" is curiously apt. Geophysicists have
"known" for ages that eddies in the liquid core cause magnetic fields --
but when they try to model them on computers, the models go all to hell.

Post by Frank McCoy
The very roundness of the earth (or to be correct, its
oblateness) is determined by gravity and spin

Roundness is forced by gravity, oblateness by spin.

Post by Frank McCoy
... holding the Earth to
the balance of the two forces to a roundness within one part in 1000;
as few mountains indeed exceed 5 miles in height.

But the variation from equatorial radius to polar radius is much greater.
Equatorial radius: 6378 km
Polar radius: 6357 km

IIRC the highest mountain on Earth is Chimborazo, in Ecuador, when
measured from Earth's centre.

Post by Frank McCoy
People talk about "plate tectonics" and the "conveyer belt" of
the oceans ...

Plate tectonics, yes, but the ocean conveyor has nothing to do with this
discussion: it is driven solely by sunlight.

Post by Frank McCoy
And the "solid" Earth we live on, that set on top of the whole
thing? That's the scum" that's been scraped off the top of the kettle
over billions of years ... the LIGHT shit that floated to the top and
wouldn't go back down with the good stuff.

Exactly right. Scary and depressing, isn't it. Sort of like being a mite
crawling around the veins in blue cheese.

Post by Frank McCoy
Around the world
today there are at least half a dozen *major* disasters waiting to
happen ... on the scale of a major meteorite strike on a large city
... and yet hardly anybody is watching. The disaster this week
(Mid-December 2004) in the Indian Ocean is just a *tiny* hint of the
things that could hit. Yet we pay more attention to the possibility
of a rock hitting us from space than we do to the more real threat of
a Tsunami completely wiping out the East coast of the USA, with no
warning at all to evacuate, when we COULD have relatively cheap
warning systems in place globally, like Japan, Alaska, and Hawaii have
done for most of the Pacific.

Both threats are very real, minor earth tremors and small rocks from space
are everyday occurences. Big ones are rare. They have to be; if they were
common, life could not exist here. That was the situation for the first
half-billion years of Earth's existence as the planets swept up the
remains of the nebula from which they formed.

And both threats are monitored. But our understanding of geophysics is
still, as the saying goes, "in its infancy". It's easier to look for rocks
heading our way. (Not much easier; most of them are discovered on their
way out.) Most large earthquakes happen on the edge of the Pacific, the
Ring of Fire, so the greatest danger from tsunamis is there.

Post by Frank McCoy
... we COULD have relatively cheap
warning systems in place globally ....

Expect them to be in place soon. Nothing like a good kick in the teeth to
get things moving.

I hope you don't find anything here offensive, Frank. Not at all my
intention (although I have the tact of the orc I pretend to be). I just
wanted to amplify, correct where necessary, and ... ramble.

[Frank McCoy]

Post by Shagrat

Post by Frank McCoy
We build railroad tracks, clear across two thousand miles of
country, where an extra inch of difference could spell instant
disaster for speeding trains going 50-60mph, without ever expecting
anything to change all along that route. Oh, it's true that we build
in certain "leeway" to allow for thermal expansion from temperature
extremes, wind and other effects on bridges and such ... But the
assumption is that the "real" distance between two towers on each side
of a gorge won't change more than a few fractions of an inch in
centuries.

Unless the gorge indicates a geological fault, the towers *won't* change
in centuries. Continents, with certain exceptions such as the rift valley
in Africa, sit atop single plates and their centres remain stable for tens
of millions of years.

Post by Frank McCoy
It's the very liquid nature of the core (I understand
anyway) that allows us to have a geomagnetic field ... what we use to
give us compass-directions. Without the core being liquid, the dynamo
that drives the Earth's magnetic field would stop.

A very neat point. Without the magnetic field, life would not be possible
at the Earth's surface. It isn't on Mars. Life would continue within the
earth itsel: there appears to be more biomass living in cracks underground
than on the entire surface but multicellular life is impossible there.
Oceanic life would also continue.
Your comment "(I understand anyway)" is curiously apt. Geophysicists have
"known" for ages that eddies in the liquid core cause magnetic fields --
but when they try to model them on computers, the models go all to hell.

Post by Frank McCoy
The very roundness of the earth (or to be correct, its
oblateness) is determined by gravity and spin

Roundness is forced by gravity, oblateness by spin.

Post by Frank McCoy
... holding the Earth to
the balance of the two forces to a roundness within one part in 1000;
as few mountains indeed exceed 5 miles in height.

But the variation from equatorial radius to polar radius is much greater.
Equatorial radius: 6378 km
Polar radius: 6357 km
IIRC the highest mountain on Earth is Chimborazo, in Ecuador, when
measured from Earth's centre.

Post by Frank McCoy
People talk about "plate tectonics" and the "conveyer belt" of
the oceans ...

Plate tectonics, yes, but the ocean conveyor has nothing to do with this
discussion: it is driven solely by sunlight.

Post by Frank McCoy
And the "solid" Earth we live on, that set on top of the whole
thing? That's the scum" that's been scraped off the top of the kettle
over billions of years ... the LIGHT shit that floated to the top and
wouldn't go back down with the good stuff.

Exactly right. Scary and depressing, isn't it. Sort of like being a mite
crawling around the veins in blue cheese.

Post by Frank McCoy
Around the world
today there are at least half a dozen *major* disasters waiting to
happen ... on the scale of a major meteorite strike on a large city
... and yet hardly anybody is watching. The disaster this week
(Mid-December 2004) in the Indian Ocean is just a *tiny* hint of the
things that could hit. Yet we pay more attention to the possibility
of a rock hitting us from space than we do to the more real threat of
a Tsunami completely wiping out the East coast of the USA, with no
warning at all to evacuate, when we COULD have relatively cheap
warning systems in place globally, like Japan, Alaska, and Hawaii have
done for most of the Pacific.

Both threats are very real, minor earth tremors and small rocks from space
are everyday occurences. Big ones are rare. They have to be; if they were
common, life could not exist here. That was the situation for the first
half-billion years of Earth's existence as the planets swept up the
remains of the nebula from which they formed.
And both threats are monitored. But our understanding of geophysics is
still, as the saying goes, "in its infancy". It's easier to look for rocks
heading our way. (Not much easier; most of them are discovered on their
way out.) Most large earthquakes happen on the edge of the Pacific, the
Ring of Fire, so the greatest danger from tsunamis is there.

Post by Frank McCoy
... we COULD have relatively cheap
warning systems in place globally ....

Expect them to be in place soon. Nothing like a good kick in the teeth to
get things moving.
I hope you don't find anything here offensive, Frank. Not at all my
intention (although I have the tact of the orc I pretend to be). I just
wanted to amplify, correct where necessary, and ... ramble.

That's why I like posting in my froup:
It invites comment.

[Öldman©]

NOTE: This message was sent thru a mail2news gateway.
No effort was made to verify the identity of the sender.
--------------------------------------------------------
On Mon, 27 Dec 2004 22:41:20 -0600,Frank McCoy's cat ran across
the 'puter keyboard and out came...
«In alt.fan.frank.mccoy Shagrat <***@sympatico.ca> wrote:
«
«>Frank McCoy <***@millcomm.com> wrote in
«>news:***@4ax.com:
«>
«>Hee hee. I *said* I would give a rambling reply:
«>
«>> We build railroad tracks, clear across two thousand miles of
«>> country, where an extra inch of difference could spell instant
«>> disaster for speeding trains going 50-60mph, without ever expecting
«>> anything to change all along that route. Oh, it's true that we build
«>> in certain "leeway" to allow for thermal expansion from temperature
«>> extremes, wind and other effects on bridges and such ... But the
«>> assumption is that the "real" distance between two towers on each side
«>> of a gorge won't change more than a few fractions of an inch in
«>> centuries.
«>
«>Unless the gorge indicates a geological fault, the towers *won't* change
«>in centuries. Continents, with certain exceptions such as the rift valley
«>in Africa, sit atop single plates and their centres remain stable for tens
«>of millions of years.
«>
«>> It's the very liquid nature of the core (I understand
«>> anyway) that allows us to have a geomagnetic field ... what we use to
«>> give us compass-directions. Without the core being liquid, the dynamo
«>> that drives the Earth's magnetic field would stop.

?? The magnetic field of the sun induces electrical currents in the core,
these electrical currents (which are VERY large) then generate the magnetic
field of the earth, a separate force from gravity. The poles 'wander' due to
the liquid iron having convection currents flowing which the electrical
currents would follow for the most part due to the fact that the conductivity
of iron changes with temperature.

My hypothesis is that the core of the earth rotates at a different rate than
the outer crust, is liquid iron from depth 'a' to depth 'b' then solid again
from pressure at the center. Like a dancer doing a spin the smaller center
core would have to rotate at a higher speed than the outer crust. What else would
explain the reversal of the magnetic field and the wander of the poles?

Consider the elecrical/magnetic properties of the core!

I think that the suns magnetic field is caused by the thermonuculear explosions
that constantly take place, consider the electromagnetic 'pulse' generated by
one H bomb here on earth. It is well known that HUGE electrical currents flow
on the suns surface that cause large magnatic fields.

«>
«>A very neat point. Without the magnetic field, life would not be possible
«>at the Earth's surface. It isn't on Mars. Life would continue within the
«>earth itsel: there appears to be more biomass living in cracks underground
«>than on the entire surface but multicellular life is impossible there.
«>Oceanic life would also continue.

?? Do you not mean gravity. It is what holds the atmosphere in place!

«>
«>Your comment "(I understand anyway)" is curiously apt. Geophysicists have
«>"known" for ages that eddies in the liquid core cause magnetic fields --
«>but when they try to model them on computers, the models go all to hell.
«>
«>> The very roundness of the earth (or to be correct, its
«>> oblateness) is determined by gravity and spin
«>
«>Roundness is forced by gravity, oblateness by spin.
«>
«>> ... holding the Earth to
«>> the balance of the two forces to a roundness within one part in 1000;
«>> as few mountains indeed exceed 5 miles in height.
«>
«>But the variation from equatorial radius to polar radius is much greater.
«>Equatorial radius: 6378 km
«>Polar radius: 6357 km
«>
«>IIRC the highest mountain on Earth is Chimborazo, in Ecuador, when
«>measured from Earth's centre.
«>
«>> People talk about "plate tectonics" and the "conveyer belt" of
«>> the oceans ...
«>
«>Plate tectonics, yes, but the ocean conveyor has nothing to do with this
«>discussion: it is driven solely by sunlight.
«>
«>> And the "solid" Earth we live on, that set on top of the whole
«>> thing? That's the scum" that's been scraped off the top of the kettle
«>> over billions of years ... the LIGHT shit that floated to the top and
«>> wouldn't go back down with the good stuff.
«>
«>Exactly right. Scary and depressing, isn't it. Sort of like being a mite
«>crawling around the veins in blue cheese.
«>
«>> Around the world
«>> today there are at least half a dozen *major* disasters waiting to
«>> happen ... on the scale of a major meteorite strike on a large city
«>> ... and yet hardly anybody is watching. The disaster this week
«>> (Mid-December 2004) in the Indian Ocean is just a *tiny* hint of the
«>> things that could hit. Yet we pay more attention to the possibility
«>> of a rock hitting us from space than we do to the more real threat of
«>> a Tsunami completely wiping out the East coast of the USA, with no
«>> warning at all to evacuate, when we COULD have relatively cheap
«>> warning systems in place globally, like Japan, Alaska, and Hawaii have
«>> done for most of the Pacific.
«>
«>Both threats are very real, minor earth tremors and small rocks from space
«>are everyday occurences. Big ones are rare. They have to be; if they were
«>common, life could not exist here. That was the situation for the first
«>half-billion years of Earth's existence as the planets swept up the
«>remains of the nebula from which they formed.
«>
«>And both threats are monitored. But our understanding of geophysics is
«>still, as the saying goes, "in its infancy". It's easier to look for rocks
«>heading our way. (Not much easier; most of them are discovered on their
«>way out.) Most large earthquakes happen on the edge of the Pacific, the
«>Ring of Fire, so the greatest danger from tsunamis is there.
«>
«>> ... we COULD have relatively cheap
«>> warning systems in place globally ....

I will build the electroincs, you program same?

How could we monitor sea levels? Or would we use an alarm system tied
into the earthquake monitors? Should not some one have seen the tidal
wave would happen as a result of the quake?

«>
«>Expect them to be in place soon. Nothing like a good kick in the teeth to
«>get things moving.
«>
«>I hope you don't find anything here offensive, Frank. Not at all my
«>intention (although I have the tact of the orc I pretend to be). I just
«>wanted to amplify, correct where necessary, and ... ramble.
«
«That's why I like posting in my froup:
«It invites comment.
«
«
Interesting discussion.

[Denny Wheeler]

On Tue, 28 Dec 2004 00:19:39 -0700, Öldman© <***@dizum.com>
wrote:

(re tsunamis caused by quakes and those caused by large-meteor strikes
in the ocean)

Post by Öldman©
«>And both threats are monitored. But our understanding of geophysics is
«>still, as the saying goes, "in its infancy". It's easier to look for rocks
«>heading our way. (Not much easier; most of them are discovered on their
«>way out.) Most large earthquakes happen on the edge of the Pacific, the
«>Ring of Fire, so the greatest danger from tsunamis is there.
«>
«>> ... we COULD have relatively cheap
«>> warning systems in place globally ....
I will build the electroincs, you program same?
How could we monitor sea levels? Or would we use an alarm system tied
into the earthquake monitors?

You might start by going here:
http://www.noaanews.noaa.gov/stories2004/s2357.htm

Overall article with links about the West Coast/Alaska Tsunami Warning
Center, and much info about tsunamis in general.

Post by Öldman©
Should not some one have seen the tidal
wave would happen as a result of the quake?

They did. Problem was getting the word out, QUICKLY, to the areas
endangered.
--
-denny-

Some people are offence kleptomaniacs -- whenever they see
an offence that isn't nailed down, they take it ;-)
--David C. Pugh, in alt.callahans

[Frank McCoy]

Post by Öldman©
I will build the electroincs, you program same?
How could we monitor sea levels? Or would we use an alarm system tied
into the earthquake monitors? Should not some one have seen the tidal
wave would happen as a result of the quake?

I'm not sure how they work; but Hawaii and Japan put in Tsunami
warning systems in the Pacific that work pretty well. All automatic;
needing minimal service. A long shallow ripple makes a BIG wave when
it hits land, while normal waves don't effect the system at all. A
series of widely-spaced automatic buoys, I think.

Yeah, it costs a few bucks to install ... But considering the lives
saved per buck spent ....

I'm not sure; but I *suspect* they could do something right now with
existing satellite ranging systems, since they're presently sensitive
to fractional-inches that can be used to measure ocean-depths merely
by the gravitational difference between water and land making
differing ocean heights. There somebody *would* have to write the
software. But I'd volunteer, if they needed somebody.

[Tim Merrigan]

Post by Frank McCoy

Post by Öldman©
I will build the electroincs, you program same?
How could we monitor sea levels? Or would we use an alarm system tied
into the earthquake monitors? Should not some one have seen the tidal
wave would happen as a result of the quake?

I'm not sure how they work; but Hawaii and Japan put in Tsunami
warning systems in the Pacific that work pretty well. All automatic;
needing minimal service. A long shallow ripple makes a BIG wave when
it hits land, while normal waves don't effect the system at all. A
series of widely-spaced automatic buoys, I think.
Yeah, it costs a few bucks to install ... But considering the lives
saved per buck spent ....
I'm not sure; but I *suspect* they could do something right now with
existing satellite ranging systems, since they're presently sensitive
to fractional-inches that can be used to measure ocean-depths merely
by the gravitational difference between water and land making
differing ocean heights. There somebody *would* have to write the
software. But I'd volunteer, if they needed somebody.

According to an NPR story about them today (Wednesday 2004-12-29)
they're pressure sensors on the ocean floor, linked by sonic signals to
buoys, which are in turn linked by rodeo to ground based stations.

[Denny Wheeler]

According to an NPR story about them today (Wednesday 2004-12-29)=20
they're pressure sensors on the ocean floor, linked by sonic signals to=20
buoys, which are in turn linked by rodeo to ground based stations.

See http://www.magazine.noaa.gov/stories/mag153.htm

<attempts to stifle smartass remark about buoys "linked by rodeo"....>

--
-denny-

Some people are offence kleptomaniacs -- whenever they see
an offence that isn't nailed down, they take it ;-)
--David C. Pugh, in alt.callahans

[Frank McCoy]

In alt.fan.frank.mccoy Denny Wheeler

Post by Denny Wheeler

According to an NPR story about them today (Wednesday 2004-12-29)=20
they're pressure sensors on the ocean floor, linked by sonic signals to=20
buoys, which are in turn linked by rodeo to ground based stations.

See http://www.magazine.noaa.gov/stories/mag153.htm
<attempts to stifle smartass remark about buoys "linked by rodeo"....>

I was tempted ....

[Shagrat]

Post by Öldman©
?? The magnetic field of the sun induces electrical currents in the core,

Afraid not, Old Fella. The Sun's magnetic field has no effect on Earth.

Post by Öldman©
My hypothesis is that the core of the earth rotates at a different
rate than the outer crust, is liquid iron from depth 'a' to depth 'b'
then solid again from pressure at the center.

I believe you are correct about the core rotating more rapidly than the
surface, but I'm not sufficiently well-versed in the subject to say why or
by how much. The dual-phase core has been known for decades.

A recent discovery that came as a surprise was that the inner surface of
the mantle, where it meets the liquid iron core, is neither uniform nor
smooth -- it has its own high and low areas like continents and ocean
abysses on the surface.

Post by Öldman©
Like a dancer doing a
spin the smaller center core would have to rotate at a higher speed
than the outer crust. What else would explain the reversal of the
magnetic field and the wander of the poles?

Good question! Neither the regular reversals nor the wandering of the
poles are well understood.

Post by Öldman©
«>A very neat point. Without the magnetic field, life would not be
possible «>at the Earth's surface. It isn't on Mars. Life would
continue within the «>earth itsel: there appears to be more biomass
living in cracks underground «>than on the entire surface but
multicellular life is impossible there. «>Oceanic life would also
continue.
?? Do you not mean gravity. It is what holds the atmosphere in place!

Sorry, I wasn't very clear about this. Radiation from the Sun bakes the
Martian soil (incidentally making it so chemically active that some of the
Viking lander soil tests gave false positives for life) and would disrupt
any complex molecules formed by life. If there is life on Mars, it is
subterranean (subarean?) in nature. Earth, unlike Mars, has an iron dynamo
in its centre that provides us with a strong, and highly protective,
magnetic field. You may recall that the Pioneer space probes in the late
'50s sent back data showing the existence of powerful magnetic belts above
the atmosphere (the Van Allen Belts). Without the magnetic fields we fry.
Remember that the next time you see an aurora in the sky. It is more than
just beautiful, awesome, and mysterious; it is the visible sign of
something absolutely necessary for our existence.

(When I started university in 1967, I planned to study Astronomy. I soon
changed my major to beer but I still try to keep up with the subject.)

Post by Öldman©
«>> ... we COULD have relatively cheap
«>> warning systems in place globally ....
I will build the electroincs, you program same?
How could we monitor sea levels? Or would we use an alarm system tied
into the earthquake monitors? Should not some one have seen the tidal
wave would happen as a result of the quake?

No need to reinvent the wheel; several Pacific countries, where tsunamis
are common, have developed a very useful warning network. Australia has
announced that they will extend their coverage into the Indian Ocean.
Incidentally, this is the first tsunami in the Indian Ocean since 1883.
(Was that Krakatoa?)

Post by Öldman©
Interesting discussion.

Decidedly so.

[Denny Wheeler]

On Wed, 29 Dec 2004 09:14:33 GMT, Shagrat

Post by Shagrat
Incidentally, this is the first tsunami in the Indian Ocean since 1883.
(Was that Krakatoa?)

Yes. August 26, 1883.
Good article on it here:
http://www.drgeorgepc.com/Vocano1883Krakatoa.html
--
-denny-

Some people are offence kleptomaniacs -- whenever they see
an offence that isn't nailed down, they take it ;-)
--David C. Pugh, in alt.callahans