Re: Literally earth-shaking, quake shifted the pole

From: Ralph Nesbitt (ralph-nesbitt_at_sbcglobal.net)
Date: 01/06/05 

Date: Thu, 06 Jan 2005 03:33:07 GMT

"David Ford" <Nospam@internode.on.net> wrote in message
news:41d8a3f9@duster.adelaide.on.net...
> Franz Heymann wrote:
> > "David Ford" <Nospam@internode.on.net> wrote in message
> > news:41d811e3@duster.adelaide.on.net...
> >
> >>I found this:
> >>
> >>--
> >>
> >>
> >>http://www.nature.com/news/2004/041229/full/041229-6.html
> >>
> >>Sumatran quake sped up Earth's rotation
> >>Michael Hopkin
> >>
> >>Natural disaster shaved millionths of a second off planet's day.
> >>
> >>The devastating earthquake that struck the Indian Ocean on 26
> >
> > December
> >
> >>was so powerful that it has accelerated the Earth's rotation,
> >>geophysicists have declared. They estimate that the shockwave
> >
> > shortened
> >
> >>the period of our planet's rotation by some three microseconds.
> >>
> >>The change was caused by a shift of mass towards the planet's
> >
> > centre, as
> >
> >>the Indian Ocean's heavy tectonic plate lurched underneath
> >
> > Indonesia's
> >
> >>one, say researchers at NASA's Jet Propulsion Laboratory in
> >
> > Pasadena,
> >
> >>California. This caused the globe to rotate faster, in the same way
> >
> > that
> >
> >>a spinning figure-skater accelerates by tucking in her arms.
> >
> >
> > It would have been nice if that article had mentioned that if you
> > slide one floating *** under another floating *** then number 1
> > will be pushed downwards and number 2 wiill be pushed upwards. That
> > is one of the things isostasy is about. There is no mention as to
> > whether the folk who did the calculation took that into account.
> >
> > [snip]
> >
> > Franz
>
>
>
> But according to the subduction theory, it passes a compacted much
> denser crust than the surrounding rocks above, and slightly denser than
> the hotter mantle immediately below the descending slab), under a
> lighter crustal plate. As already pointed out, isostasy due to mass
> difference sorts itself out in the longer-term, but this is a short-term
> measurable change that has occurred instantaneously, in geological
> terms. And as already pointed out isostasy is not a factor that has any
> impact in Gross's determination, only the relative NET vertical MASS
> vector, toward or away from the centre of Earth does.
>
> Credit where credit is due; this result is consistent with the
> expectations of subduction. I don't say that lightly, but it is what
> Earth itself, is indicating, and as always, I’ll listen to what Earth
> tells us all, not for what any theory wants (PT or EE.)
>
> --
>
> Having said that, I considered the implications in light of my usual
> expansionary view of trench dynamics, i.e., of a rising less dense
> material, spreading and encroaching, pressing down upon the denser
> oceanic crust and burying it (which I have described many times). So I
> find it is also consistent with that expansionary interpretation of
> relative NET mass movements in trenches; I just had not realised it
> could take that form of NET mass movement.
>
> --
>
> The one significant reservation I do have about what Dr Richard Gross
> has said in the article I posted is;
>
>
> “…Overall, the Earth's rotation tends to slow down as the Moon's gravity
> pulls on its seas and continents, causing bulges that give the opposite
> effect of Sunday's compacting quake. …” – Gross
>
>
> Now, I have never bought into this standard bulging ‘drag’ explanation
> of the observed routine slowing of Earth’s rotation, because it is also
> consistent with NET upward movement of MASS in Earth, and thus
> indicative of Earth expansion (which I quantified in August 1999 to be
> 3.0 mm/yr from the VLBI data set … which again, was far less than the 18
> mm/yr I was seeking … this is what Earth is telling us, so be it - but
> this still means a measurable above noise Earth expansion is actually
> present within the VLBI dataset, nonetheless …). So when Dr. Gross goes
> on to make the following closing remarks below within the Nature
> article, it confirms and reinforces my previous view regarding the
> Earth’s rotational slowing;
>
>
> “ …This is partly because, when the atomic clock system was adopted in
> 1967, physicists chose 1900 as the year with the best average data on
> how fast the Earth spins. This meant that, because of Earth's natural
> slowing, the atomic clock was already running fast when it was set up.
>
> On average, just over one leap second is needed every year, O'Brian
> says. That makes the fact that we haven't had one since 1998 something
> of a surprise. "Since the last leap second the Earth's rotation seems to
> have been changing at a very slow rate," he says.” - Gross
>
>
> Now, I think we can all find quick agreement that Gross’s explanation
> the, “…Moon's gravity pulls on its seas and continents, causing bulges
> …”, did not suddenly end in 1998. i.e., the moon is still in its usual
> orbit and tides still occur as ever before, and there have not been any
> notable MASS slumps off continental margins, nor unusually large
> earthquakes like this current event in the 1998 to present interim, that
> could have otherwise counteracted the rotational slow-down process of
Earth.
>
> This tends to falsify Gross’s previous explanation for what actually
> causes this usual (but patently very unusual) continual slow-down of
> Earth rotation, and this fact that the moon and tides have not gone
> away, leaves us with the much more logical interpretation that this
> routine slow-down of Earth’s rotation is due to NET UPWARD MOVEMENT OF
> MASS IN EARTH, and thus serves to reinforce the expanding Earth theory’s
> interpretation of the slow-down (which, as already mentioned, is
> confirmed to be a feature of global geodetic dataset’s vertical vector
> component analysis).
>
> So, we are left with a Plate Tectonic Theory, and Expansionary theory,
> neither of whish presents a synthesis that adequately and fully accounts
> for the extraordinary observations being uncovered.
>
> --
>
> Footnote: I would like to point out that I have always recognised deep
> burial of rocks and their eventual uplift, and this has always been a
> consideration within my view; from the text at my website (which remains
> unchanged in any way whatever since late 1999):
>
> “… Nevertheless, there exists convincing metamorphic
> (temperature/pressure) mineralogical evidence of ancient deep geological
> burial processes that buried rocks to depths greater than the average
> thickness of continental crust--then subsequent uplift of these rocks to
> the near surface temperature-pressure environment again. This deep
> burial evidence is claimed as proof of subduction but this completely
> fails to explain how these rocks were uplifted to the surface again.
> This could never happen according to the standard plate tectonic model.
> Such extreme uplift clearly demands through-crust vertical orogenesis
> as nothing else could achieve the result. …”.
> http://www.geocities.com/CapeCanaveral/Launchpad/8098/1.htm
>
> i.e. Plate Tectonic theory provides a deep burial concept, but provides
> no mechanism of deep exhumations of these altered rocks; the reverse is
> true of Earth expansion, it embodies a natural deep exhumation
> mechanism, but no recognised genuinely deep burial mechanism. It is that
> on-going inadequacy in both theoretical synthesis’s which I sought to
> highlight with the above remarks, and this remains the situation still,
> today.
>
You fail to consider/take into consideration the number of subduction EQ's
irrespective of size annually. What is the total net movement between paired
expanding ridges & subduction zones?
Ralph Nesbitt