Science Olympiad Dynamic Planet Practice Test

Which of the following is NOT a source of mantle convection?

1. Heat from the Earth's core

2. Radiation from the sun

3. Radioactive decay within the Earth

4. Residual heat from Earth's formation

The correct answer is: Radiation from the sun

The correct answer is indeed that radiation from the sun is not a source of mantle convection. Mantle convection refers to the process by which heat from the Earth's interior causes the mantle to circulate. This internal heat primarily originates from several key sources, including heat from the Earth's core, residual heat from the planet's initial formation, and the heat produced by the radioactive decay of elements present within the Earth. Heat from the Earth's core is essential for driving convection since it provides the necessary thermal energy to create temperature differences within the mantle, leading to the movement of material. Similarly, residual heat from Earth's formation, which has not yet dissipated, contributes to the overall thermal state of the mantle. The process of radioactive decay adds another important dimension, as it continuously generates heat within the mantle from the breakdown of isotopes such as uranium and thorium. In contrast, radiation from the sun primarily influences the Earth's surface and atmosphere, rather than affecting the mantle. The energy received from the sun does not penetrate deeply into the Earth, and thus it does not play a role in the thermal dynamics of the mantle. Understanding the sources of heat that drive mantle convection is crucial for comprehending tectonic activity, which plays a vital role in shaping our planet's surface.