Glossary Terms for Chapter 10- Plate Tectonics Flashcards
Asthenosphere
A layer of ‘plastic’ semi-solid rock in the lower mantle
Continental Drift
The separating of continents by drifting across oceans
Magnetic Striping
Patterns of magnetism (magnetite) trapped in rocks on each side of plate boundaries.
The magnetism is ‘striped’ because of the alternating magnetism of the Earth every few million years.
Ocean trench
a deep trench in the ocean floor that is much deeper than the rest of the ocean floor and is formed when two oceanic plates collide and the faster oceanic place subducts.
Plate tectonics
the theory that the Earth’s crust is cracked into many large pieces called plates, that move on the Earth’s asthenosphere.
Rifting
the process of continents breaking up, subsiding and allowing in the sea.
The two tectonic plates surrounding the Red Sea are rifting, which means in the future, the Red Sea will become the next big ocean or mass of water.
Seafloor Spreading
the process of new crust forming at the ocean ridges and spreading outwards.
Subduction
Occurring at subduction zones along the converging boundaries where the denser crust sinks down into the Earth.
When oceanic crust collides with the continental crust, the oceanic plate sinks below the continental plate.
Continental Crust
The crust that forms the continents
Converging boundary
Where plates are colliding with each other
Diverging boundary
Where plates are diving or separating and moving apart from one another in opposite directions.
GPS Ground Station
a receiver and computer that can detect satellite signals and calculate its position on the Earth’s surface.
The GPS Ground System measures the movement of the plates to determine whether they have moved, in which direction and by how much.
Island Arc
a chain of islands formed at the edges of colliding/converging tectonic plates where one plate subducts.
oceanic crust
the crust that forms the ocean floor
Transform Boundary
where plates are sliding parallel to each other but in opposite directions.
Earthquake
the rapid movement of the ground, usually back and forth and up and down in a wave motion due to the movement of tectonic plates.
Mostly along transforming boundaries but the strongest and most damaging occur along converging boundaries.
The lithosphere is more commonly known as the….
crust
Which two things are formed at transforming boundaries?
the fault lines and mountain folds
Epicentre
The point on the Earth’s surface directly above the focus of an earthquake.
Focus
The place below ground where the earthquake starts.
hot spots
isolated places away from plate boundaries where a low of hot magma is being created, often forming chains of volcanic islands as the crusts move.
lava
molten rock that has erupted above the Earth’s surface
magma
molten rock below the Earth’s surface
Primary wave (P- wave)
a longitudinal seismic wave that travels fast through the Earth and shake the Earth side to side
