Earth's Internal Heat Budget Quiz

Solar radiation is the dominant external energy source, contributing 173,000 terawatts (TW) to Earth's total energy budget at the surface. This far outweighs the contribution of Earth's internal heat, which only accounts for 0.03% of the total energy budget.

The two main sources of Earth's internal heat are radiogenic heat produced by the radioactive decay of isotopes in the mantle and crust, and the primordial heat left over from the formation of Earth. These sources contribute roughly equal amounts of heat to the planet, with radiogenic heat estimated to be 47±2 terawatts (TW). Despite its geological significance, Earth's internal heat only contributes 0.03% of Earth's total energy budget at the surface, which is dominated by 173,000 TW of incoming solar radiation.

On land and at the ocean floor, the sensible heat absorbed from non-reflected insolation flows inward only by means of thermal conduction, and thus penetrates only several tens of centimeters on the daily cycle and only several tens of meters on the annual cycle.

<p>Earth's internal heat powers most geological processes, including mantle convection, plate tectonics, mountain building, rock metamorphism, and volcanism. It also sustains a geodynamo which generates Earth's magnetic field.</p> Signup and view all the answers

<p>Earth's internal heat comes from two main sources in roughly equal amounts: the radiogenic heat produced by the radioactive decay of isotopes in the mantle and crust, and the primordial heat left over from the formation of Earth. It contributes only 0.03% of Earth's total energy budget at the surface.</p> Signup and view all the answers

<p>Solar radiation is minimally relevant for processes internal to Earth's crust, as it only penetrates several tens of centimeters on the daily cycle and several tens of meters on the annual cycle due to thermal conduction.</p> Signup and view all the answers

<p>Earth's internal heat powers mantle convection, plate tectonics, mountain building, rock metamorphism, and volcanism.</p> Signup and view all the answers

<p>Thermal conduction allows solar radiation to flow inward only by means of thermal conduction, and thus penetrates only several tens of centimeters on the daily cycle and only several tens of meters on the annual cycle.</p> Signup and view all the answers

<p>Earth's internal heat contributes only 0.03% of Earth's total energy budget at the surface, while incoming solar radiation dominates the energy budget with 173,000 terawatts.</p> Signup and view all the answers

<p>Convective heat transfer within the planet's high-temperature metallic core is theorized to sustain a geodynamo which generates Earth's magnetic field.</p> Signup and view all the answers