QUOTE(cladking @ Jun 2 2007, 09:46 PM) [snapback]1706308[/snapback]
Excellent point.
It would also change the shape a little but this should be of less importance.
Yeah, The whole point is that in fact the core itself is not melting the ice caps, but a chain of events is the cause.
1. Oceans Heating: The evidence is clear that oceans are heating, not the atmosphere. Recent measurements clearly show this, as polar ice caps are melting when over water but increasing when over land.
2. Hot Spot Rotating: A hot spot rotating within the earth is the only apparent explanation. The cyclic nature of ice ages is consistent with a rotation within the earth, which would be cycle, but not environmental effects, which would be widely varying. No solar effects show proper correlations with 100,000 year cycles or heating patterns.
3. Broad Heating Pattern: The heating of the oceans is not a localized effect which could be attributed to ocean currents shifting, as both polar ice caps are melting, and both Pacific and Atlantic sides are affected. Such a broad base of heating points to a large mass moving deep within the earth. The rotation that is occurring near the outer crust of the earth has a much shorter cycle.
4. Orbital Plane Tilt: The Earth's orbital plane tilt follows a 100,000 year cycle. This correlation with ice age cycles is too much of a coincidence to be accidental. Muller and MacDonald reported on this in Science in 1997
(Link), but their theory was aligned upon supposed atmospheric heating, which is a faulty assumption originating with propaganda. Instead, the orbital tilt cycle can explain why a hot spot rotates within the Earth.
When the Earth's orbital plane tilts, both gravitational and inertial effects could cause the Earth's core to shift, if it is more dense than the fluid around it, which it probably is. It should also be hotter than the fluid around it, because 4.5 billion years of cooling should create a temperature gradient.
This means that shifting of the Earth's core would cause one side of the earth to get hotter, and one side to get cooler. If the hotter side is covered by an ocean, then that ocean gets hotter. Ocean currents would spread the heat to all oceans.
The biggest question with this theory is why have the cycles only occurred during the past million years. Possible explanations are these: Perhaps the cool-down of the earth only recently created enough differential temperature between the Earth's core and it's surrounding fluid. Perhaps the heat-up occurred on land in earlier times, which would not result in an ice age. Perhaps other factors over-rid this effect in earlier times, since earlier ice ages had much larger cycles. Perhaps a near miss by an asteroid or comet shifted the plane of the Earth's orbit one million years ago.
Edit: forgot a link.