Core Theory

摘要

Radioactive potassium, common enough on Earth to make potassium-rich bananas one of "hottest" foods around, appears also to be a substantial source of heat in the Earth's core, according to recent experiments by University of California, Berkeley (UCB) geophysicists. Radioactive potassium, uranium and thorium are thought to be the three main sources of heat in the Earth's interior, aside from that generated by the formation of the planet. Together, the heat keeps the mantle actively churning and the core generating a protective magnetic field. But the UC Berkeley geophysicists have found much less potassium in the Earth's crust and mantle than would be expected based on the composition of rocky meteors that supposedly formed the Earth. If. as some have proposed, the missing potassium resides in the Earth's iron core, how did an element as light as potassium get there, especially since iron and potassium don't mix?