Plate Tectonics Flashcards
Seismic Waves
Waves of energy that travel through the Earth’s crust, caused by earthquakes.
Continental Drift
Movement of the plates of the Earth’s crust in relation to each other.
Pangaea
A super-continent that existed about 225 million years ago. All of the landmasses that existed at this time were joined together to form this super-continent.
Panthalassa
The vast sea surrounding the supercontinent of Pangaea.
Plate Tectonics
The theory concerning the movement of the continental plates.
Mantle
Thick layer inside the Earth, below the crust. Most of the mantle is solid rock, although the upper part is molten rock called magma.
Convection Current
A circular movement that occurs when warmer, less dense fluid particles rise and cooler, denser fluid particles sink.
Continental Crust
The plates of the Earth’s crust that make up the land.
Oceanic Crust
One of the types of crust that makes up the Earth’s outer layer. Oceanic crust is thinner than continental crust and made up of dense, heavy rocks such as basalt.
Subduction
A process in which two tectonic plates push against each other, and oceanic crust sinks below the less dense continental crust.
Destructive Plate Boundaries
A convergent boundary where two plates collide.
Constructive Plate Boundaries
A plate that creates new land from cooling magma.
Ocean Ridges
An area where the tectonic plates move apart, allowing magma from the mantle to rise, forming underwater volcanoes and creating new oceanic crust as it is cooled and solidified by sea water.
Hotspots
A localised place where an activity occurs.
Conservative Plate Boundaries
When two plates slip/slide past each other. Nothing is created nor destroyed - conservative. This is the main type of boundary where Earthquakes occur. The best example of a transform boundary is the San Andreas Fault.
