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Old August 5th 03, 10:55 AM posted to rec.arts.sf.science,sci.geo.geology,sci.geo.meteorology
Alastair McDonald Alastair McDonald is offline
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Default What causes big climate changes? scientists reaffirm...


"Old Physics" wrote in message
om...
Orbital Resonances

The mean solar day loses about 230 seconds over the sidereal lunar
orbit, SLO, every million years.
Take the present SLO, 27.32166 days and divide by 27.5. Subtract
the result from one and multiply by the SLO, 2360591.47s for the
result of 15408s. Divide this by 230s for the result of 66.5 million
years.
Follow the same procedure for 28, 28.5 and 29 msds per SLO to get
the result of 249.8, 430 and 606 million years ago respectively.
These results are very close to the cretaceous, permian,
ordovicean
and precambrian extinctions respectively.
At these times the earth's magnetic field began reversing at an
increased rate of as much as 35000 percent, and sea leavels began to
rise at high latitudes and fall at middle latitudes. Temperatures
dropped with the draining of inland seas and the icing of the poles.
Could there be a siderial link between the moon's orbit and the
earth's rotation?


You might be interested in this article in Science
http://www.sciencemag.org/cgi/conten.../286/5445/1707

Core Rotational Dynamics and Geological Events
Marianne Greff-Lefftz, 1 Hilaire Legros 2

A study of Earth's fluid core oscillations induced by lunar-solar tidal
forces, together with tidal secular deceleration of Earth's axial rotation,
shows that the rotational eigenfrequency of the fluid core and some solar
tidal waves were in resonance around 3.0 × 109, 1.8 × 109, and 3 × 108 years
ago. The associated viscomagnetic frictional power at the core boundaries may
be converted into heat and would destabilize the D" thermal layer, leading to
the generation of deep-mantle plumes, and would also increase the temperature
at the fluid core boundaries, perturbing the core dynamo process. Such
phenomena could account for large-scale episodes of continental crust
formation, the generation of flood basalts, and abrupt changes in geomagnetic
reversal frequency.

Further, Heinrich events, the calving off of iceburgs that leave a
layer of sediment an the atlantic floor, occured 65, 52, 39 and 12.6
thousand years ago. These correspond to the times when the earth's
axis was perpendicular to the poles of the Cosmic microwave
background. Could there be a cosmic directional force?


Do you have a reference for that? It is more on topic :-)

Cheers, Alastair.