Science Olympiad Dynamic Planet Practice Test

What percentage of Earth's heat is attributed to "primordial" heat?

1. 20-50%

2. 50-80%

3. 10-20%

4. 0-10%

The correct answer is: 20-50%

Primordial heat refers to the heat retained from the formation of the Earth over 4.5 billion years ago. This heat originated from several factors, including the gravitational compression during the planet's formation, energy released from the decay of radioactive isotopes, and the kinetic energy from colliding particles. Estimating the contribution of primordial heat to Earth's total temperature involves understanding the balance of heat sources and sinks within the planet. Research indicates that approximately 20-50% of the Earth's current heat can be attributed to this primordial source. This range highlights the significant but not overwhelming role that primordial heat plays in the overall thermal environment of the Earth compared to heat generated by ongoing radioactive decay and other processes. Thus, considering the total contribution of heat from various sources, option A accurately reflects the estimated percentage of Earth's heat that is attributed to primordial processes.