Plate Tectonics Flashcards
What part of the earth makes tectonic plates move?
The mantle
In plate tectonics, heat from the core causes ….. in the mantle.
Convection currents
In plate tectonics, what do convection currents do?
Slowly move the crust around
What are the two types of crust?
oceanic and continental crust
Earthquakes and volcanoes are primarily found where?
Plate boundaries
At the boundaries between plates, ….. is able to force its way to the surface and escape as lava.
Molten magma
What happens when tectonic plates meet?
Earthquakes and volcanoes
What causes convection currents in the mantle?
Heat from radioactive decay
Name one of the scientists responsible for the theory of continental drift?
Alfred Wegener
Name 3 evidential features of Wegener’s continental drift theory.
- The same types of fossilised plants and animals are find in South America and Africa
- The shape of the east coast of South America fits the west coast of Africa like pieces of a jigsaw puzzle.
- Matching rock formations and mountain chains are find in South America and Africa.
What do scientists call the large land mass which they believe existed before it broke into smaller chunks?
Pangea
Name 3 tectonic plates
- Pacific Plate (largest)
- North American Plate
- Eurasian Plate
- African Plate
- Antarctic Plate
- Indo-Australian Plate
- South American Plate
How many tectonic plates cover almost 95% of the worlds’ surface?
7
Where is the “ring of fire”?
The Pacific Plate
What is the lithosphere?
The Earth’s crust and mantle
What year did Wegener put forward his theory on continental drift?
1912
In plate tectonics, what is a plate boundary?
The region where two or more tectonic plates meet. It is a zone of intense seismic activity.
In plate tectonics, what is a mid-ocean ridge?
It is an underwater mountain range, formed by plate tectonics
In plate tectonics, what is a trench?
One of the Earth’s tectonic plate slides under another tectonic plate. (The heavier plate goes under the lighter one)
What is the Magma chamber?
A large underground pool of magma in a volcano
With regards to volcanos, what is the crater?
A bowl-shaped basin in the top of the volcano
With regards to volcanos, what is the vent?
Vent - central tube which magma travels through
What is an earthquake?
An earthquake is a sudden shockwave caused by the movements of plates at plate boundaries.
