MadSci Network: Earth Sciences |
Hi Richard, Radioactive elements such as uranium, thorium, and potassium are low abundance in the Earth, but they pack quite a punch! When radioactive elements decay, they emit atomic particles that collide with and are absorbed by the surrounding matter. This stops the particles from moving, and the energy of motion changes to heat energy. There is enough heat energy generated by radioisotope decay to cause convection within the Earth and continental drift of the crust. When a planet accretes (when pieces of matter accumulate into a larger body), energy is emitted by the when pieces of matter collide and subsequently accumulate. Though this generates a great deal of energy, most of this energy has already dissipated from the Earth's interior. Presently, radioactive isotope decay is the primary source of heat energy in the Earth's interior. Moreover, the moon probably does not cause much tidal heating of the Earth. The Earth should have much more of an effect on the moon because it is much larger, but since the moon is geologically dead this does not matter. Good luck on your paper. If you need more information, please feel free to write back. Sarah Earley CU Boulder
Try the links in the MadSci Library for more information on Earth Sciences.