There are three major phenomena to consider in ice age theories. One, there’s the fifties concept that ice ages follow the natural cycle of ice melting and forming in a cyclic manner. Two, there’s the solar concept that energy from the sun varies. And three, there’s the hot spot rotating in the center of the earth concept.

The most important fact to consider is that ice age cycles are precisely timed at 100,000 year intervals. Superficial phenomena are not that precise. Convectional currents are highly varied and imprecise. For this reason, the major cycles of ice ages do not appear to be caused by surface phenomena on the earth or the sun.

Notice the small blips on this graph of ocean temperature changes during ice age cycles.

Ocean Temperatures over 800,000 Years.
 

 

The small blips would be due to superficial phenomena such as variations in solar intensity. Scientists are measuring variations in solar intensity, and they are now saying that a cool-down is starting, and it could last for quite awhile. But this only explains the small blips on the graph, not the large ice age cycles.

The large cycles appear to correlate with changes in the earth’s orbit, which has 100,000 year elements to it. But there is no explanation of how orbital changes would heat and cool the earth. The yearly averages must always be the same for orbits in terms of distance from the sun. The tilt of the orbital plain has a 100,000 year cycle, but tilt does not change yearly averages of solar heat intensity.

A possible explanation is that the orbital tilt pulls the central core of the earth southward where there are more oceans causing oceans to heat more. Or the tilt could expose more of the southern hemisphere to the sun’s radiation where oceans absorb more of the heat. The land masses in the northern hemisphere reflect and release more heat than the oceans do.

Another explanation is that electromagnetic energy going through the center of the earth causes heating within the earth. There is a lot of energy in electromagnetic currents in space, and the energy is fed by ion plasmas from the sun. But there is no indication of why 100,000 year cycles would be involved.

The simplest explanation is that a hot mass within the earth rotates with a cycle of 100,000 years, and it heats the oceans as it gets closer to the mantle. There is always convection in hot fluids such as the earth’s center. And the heterogeneity of the earth’s center increases as cooling occurs. A hot spot could be caused by a nuclear mass burning away, or it could simply be hot material rotating.

At any rate, there has to be something more basic than the superficial effects near the surface that causes the large cycles.