continental drift
The continents slowly drifting over Earth’s surface
Pangaea
supercontinent with every continent connected.
fossil
any trace of ancient organism that has been preserved in rock
mid-ocean ridges
a crack in the ocean floor where magma comes up to regenerate the ocean floor
Sonar
a device used to bounce sound waves off underwater objects and then records the echoes of these sound waves
sea floor spreading
The process in which the ocean floor regenerates and pushes the continents
deep ocean trenches
a deep valley along the ocean floor where oceanic crust slowly sinks back to the mantle
subduction
when ocean floor sinks beneath a deep ocean trench and back into the mantle