Please find below further information on this topic.
Earth core temperature is influenced by three main factors:
1. high internal pressure inducing compression of the iron crystal structure.
2. gravitational influences of the Moon and Sun inducing small cyclic fluctuations at the solid/liquid boundary.
3. interactions with a significant amount of neutrinos crossing the inner core crystal lattice.
The first two factors keep the whole core in a relatively stable equilibrium state with variations of only tens of degrees (°K).
Only changes in solar neutrino flux can have a significant influence over a range of hundreds of degrees. Even neutrinos with lower energy levels are able to interact along their travel across the dense iron layers, and more specifically inside the inner core where they generate unstable isotopes, producing local oscillating changes in the iron crystal structure that propagate to the solid/liquid boundary.
During an increase in solar neutrino emissions the speed of those oscillations also increases, developing or reducing locally the cubic iron structure at higher speed, inducing warming mainly by friction and, to a lesser extent, by an increased ambient radioactivity. Inner heat increase is transmitted very slowly to the upper layers. with a delay of about 8 months to reach the Moho.
0n the contrary, when the solar activity decreases, the planetary core cools rather suddenly with endothermic readjustments of the cubic structure. Upper layers are progessively affected by the same relative and sudden drop in temperature.
Global warming, which is a reality, results mainly from a reduced capacity of the oceans, warmed from the seabed and saturated with buoyant organic polymers and hydrocarbon residues, to recoup heat and carbon dioxide from the atmosphere.
