Science 5.6 Flashcards
(20 cards)
What is a tectonic plate?
A massive piece of the lithosphere (solid rock) that floats on the partially melted rocks of the mantle
What is formed by tectonic plates?
Continents and the bottom of oceans
What types of tectonic plates are there?
Oceanic
Mixed (partly oceanic, partly continental)
Provide an example of an entirely oceanic plate
Pacific Plate
Provide an example of a mixed plate
South American Plate
What causes the movement of tectonic plates?
The intense heat of Earth’s interior
How does the heat of Earth’s interior cause tectonic plates to move?
The heat creates movement in the partially melted rock of the mantle - this causes tectonic plates to move very slowly
How much do tectonic plates move in a year?
A few centimetres at most
As tectonic plates move against each other, they can:
Collide
Move apart
Rub against each other
Which is thicker? The oceanic crust or the continental crust?
The continental crust
What happens when an oceanic plate collides with a continental plate?
The oceanic plate is pushed down into the mantle
What does subduction mean?
It is when part of a plate is pushed down into the mantle where it melts
Faults can form and earthquakes can happen along what part of the tectonic plates?
The edges
What can form when a tectonic plate is pushed down into the mantle?
Mountain ranges
Volcanoes
Where do tectonic plates most often move apart?
At the bottom of the oceans
What can happen when tectonic plates move apart?
Underwater earthquakes
Magma can rise up and solidify
What is created when magma rises up from the bottom of the ocean when tectonic plates separate?
Long underwater mountain ranges called mid-oceanic ridges
What happens when tectonic plates rub together?
Earthquakes
220 million years ago, what was the great continent called?
Pangea
180 million years ago, after Pangea split into 2 continents, what where the 2 continents called?
Eurasia
Gondwana
