NATS 1740 Chapter Notes - Chapter 9: Seismic Wave, Subduction, Oceanic Crust

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Tatiana Paulin

Document Summary

Seismic waves- earthquake induced vibrations that propagate throughout a planet. Core- highest density central region of a planet. Mantle- rocky region that surrounds the core and is of medium density. Crust- lowest density rock that forms a thin crust and the planets outer layer. Differentiation- process by which gravity separates materials according to density (highest sinking, lowest rising) Lithosphere- rigid outer layer of a planet that encompasses the crust and part of the mantle. As planetesimals approach forming planets their energy is changed to kinetic causing it to accelerate, upon impact the energy is converted to heat which adds to the thermal energy of the planet. Heat from differentiation- as mass moves inwards, potential energy is lost that turns into thermal energy because of the friction. Heat from radioactive decay- rock and metal the built the planets contained radioactive isotopes. When they decay subatomic particles fly off and collide with other atoms which heats them.