Thermal radiation Flashcards
What are the basic principles of thermal radiation?
The further away the electron/electron shell, the higher the energy state.
Electrons in the outer shells are energetically high
Every physical system tends towards the lowest state of energy
In e.g. hot regions of the Earth atoms are energetically excited
As, the Earth slowly cools, it gradually tends to its lowest state of energy
Excited atoms emit infra-red radiation (i.e. energy) as they ‘chill out’ by jumping to electron shells closer to the nucleus
They get rid of the energy by radiating it outwards by heat
The radiation can travel through any medium
Where is most of the heat transported to the surface from the earth’s interior is lost? Give an example
Most of the heat flow is concentrated at the mid-ocean ridges
The second most important area is basins behind subduction zones- e.g. southern Europe which is linked with a back arc basin
Where is most of heat lost at surface?
Most important: creation of new lithosphere at mid-ocean ridges/divergent plate boundaries (magma/heat from upper mantle)
Subduction zones (marginal (back-arc) basins behind island arcs)
Hot spots (magma/heat from mantle or D’’/ CMB)
