The Earth's Strcture Flashcards
What is the Earth’s structure made up off?
Crust.
Mantle.
Outer core.
Inner core.
What does the Earth look like?
It is almost spherical and it has a layered structure.
What is the bit we live on?
The crust.
What is the crust?
Its very thin.
Varies from 5km to 50km depending on if its oceanic or continental crust.
Surrounded by the atmosphere.
What is the mantle?
Has all the properties of a solid.
Except it can flow very slowly.
What happens within the mantle?
Radioactive decay takes place.
This produces a lot of heat which causes the mantle to flow in convection currents.
What is the centre of the Earth?
The core.
Made up of iron and nickel.
What is the Earth’s surface made up of?
Tectonic plates.
Where do the tectonic plates float?
The crust and the upper part of the mantle.
Why don’t the plates stay still?
Due to convection currents in the mantle causing plates to drift.
How much are most of the plates moving?
Speeds of a few cm per year.
Occasionally what do the plates do?
Move very suddenly causing earthquakes.
Where do volcanoes and earthquakes occur?
Between 2 tectonic plates.
What can’t scientists predict?
Exactly when plates move causing volcanoes and earthquakes.
How are scientists trying to find clues about when earthquakes may happen?
Strain in underground rocks.
