From: Mike Lorrey (mlorrey@datamann.com)
Date: Thu Jun 28 2001 - 09:53:54 MDT
"Robert J. Bradbury" wrote:
>
> On Wed, 27 Jun 2001, Doug Jones wrote:
>
> > > Earth's volcanos : caused by the moon
> >
> > I don't want to go chasing down the numbers right now, but I'm very,
> > very certain that the vast majority of earth's internal heating is not
> > tidal. Tell ya what- you're the one making the extraordinary claims,
> > how about you dig up the extraordinary evidence?
>
> I'll second you on this Doug. The heating comes from radioactive
> elements like 40K, uranium and thorium. The dynamo of circulating
> hot magma in convective loops drives the movement of the continents.
> Some volcanoes occur over places where these hot spots break through
> ocean floors (e.g. Hawaii). Others occur at the subduction zones
> where the ocean floor plates diving under the light continental
> plates produces enough friction to melt the rock. The volcanoes
> get helped out by the calcium carbonate that has accumulated on
> the ocean floors releasing carbon dioxide at high temperatures
> causing expansion and upward flow of the material. I've never
> heard any suggestion that the Moon is responsible for volcanoes.
Not volcanos per se, but in where they form. Note that Venus, of similar
size and makeup as the earth, has no moon. Its only tidal influence is
the Sun, which exerts ~4 times the tidal influence it does on the Earth.
Between that and its 240 day long day ( a large chunk of its year),
tidal influence is minor, but present. Residual heat and radioactive
decay play a much larger role on Venus than on Earth, but Venus has NO
plate tectonic system utilizing subduction, fault, and spreading zones
and NO strong electromagnetic field or radiation belts.
Instead, the crust is pocked with scattered volcanoes, and material
rises and falls in columns rather than plates. The Earth's system is
different from that of Venus because it has a moon of large size. If it
were simply a matter of core radioactive decay and magma convection
loops, our tectonic system would be like Venus'.
The tidal influence of the moon exerts far greater torque upon the
mantle and crust than on the innner core layers, acting like brake
shoes. This greater torque results in drag upon the outer layers because
the moon orbits far slower than the earth rotates, which is why the core
rotates faster than the mantle at a rate of ~1 additional rotation per
year, this differential rotation creates great amounts of heat at the
boundary layer, which helps maintain its fluidity. This rotational
differential also creates a stator/rotor relationship between them, and
is what generates the intense electromagnetic field that the earth has,
and intense electrical currents through the earth that result produce
additional heating from current resistance.
This differential velocity system caused by tidal drag is the only way a
terrestrial body can maintain a strong electromagnetic field over time.
We know that Mars once had an EM field, but that at its peak it was
still far weaker than the Earth's (from measurement of the residual
magnetics of rock deposits). Jovian planets generate huge magnetic
fields due to magnetohydrodynamic effects from the differing speeds of
hydrogen (a metal) gas at different lattitudes and altitudes relative to
the core body of solid metallic hydrogen.
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