Flashcards in The Earth's Structure Deck (10):
What components make up the earth's structure?
Crust, mantle, outer and inner core
Describe the crust
The bit we live on, is very thin (5 km and 50 km) and is surrounded by the atmosphere
Describe the mantle
Below the crust is the mantle. The mantle has all the properties of a solid, except that it can flow very slowly
Within the mantle, radioactive decay takes place. This produces a lot of heat, which causes the mantle to flow in convection currents
Describe the core
It's at the centre of the earth, which we think is made of iron and nickel
What is the earth's surface made up of? (short)
Describe tectonic plates
The crust ad the upper part of the mantle are cracked into a number of large pieces.
The plates don't stay in one place though. That's because thee convection currents in the mantle cause the plates to drift
What speed are most of the plates moving at?
A few cm per year relative to eachother
What causes an earthquake? (Short)
Plates moving very suddenly
Where do volcanoes and earthquakes occur?
At boundaries between 2 tectonic plates