Does radioactive decay contribute to earth's molten core?

[petrushka.googol]

The earth has an abundance of radioactive elements whose decay contributes to the molten state of the earths core (or so i am told).

 

How then does this influence the dynamic of seismic activity at hot spots on the earth like the Pacific Ring of Fire?

 

Are there convectional currents of molten magma in the earths core and if there are then how does this all add up to a seismic event on the earths crust?

[Ophiolite]

The majority of radioactive elements are found in the Earth's mantle. There are no significant quantities in the core. (I am ignoring a plausible, but generally discounted hypothesis that there is a uranium fission reactor at the very centre of the planet.) Since the radioactive decay raises the temperature of the mantle then heat loss from the core is reduced, allowing it to cool more slowly than would otherwise be the case.

 

The precise mechanisms for convection within the solid mantle are a matter of active debate. However, the net effect is to generate movement of crustal plates in response to some combination of convection current drag, slab pull from descending plates and push from new crust generated at mid-ocean ridges.

 

There is no magma in the Earth's core, which is composed primarily of iron and some nickel. There are convection currents. Those generate the Earth's magnetic field.

 

The Pacific Ring of Fire is not a hot spot. It tracks the locations in which oceanic crust is descending below (generally) continental crust. As the plate with associated sediments sinks into the mantle partial melting occurs and magma makes its way to the surface. The downward movement of the plates generates the earthquakes. Hot spots include those responsible for the Hawaian Islands and Iceland.

 

Please ask further questions if necessary.