Diminuição de intensidade das Fontes Térmicas no Interior da Terra

Abstract

This work studies the effect of the decrease of the radioactive content of the rocks in the crust over time and consequent alteration in the value of thermal sources in the crust. The thermal sources of the innermost zones (Earth's core and mantle) also undergo alteration that can be mathematically expressed by an exponential decay. The period of time used in our calculations is 4 million years. Two examples are presented. The first one is the alteration suffered by a rock sample studied in the lab. The second example considers an average value for the Earth. The differences between the actual heat flow on the surface and the heat flow in the past allow inferring its influence on the air layer close to the soil, especially on days without wind or with relatively low air speeds.