Earths Structure Flashcards
What is the crust
Thin outer layer, solid rock, average 20km
What are the 3 main parts to the earths structure
Crust, mantle, core
What is the lithosphere?
Crust and upper mantle - tectonic plates
Cold and rigid
100km thick
What is the mantle
Solid section between crust and core - gets more fluid close to core
What is the core?
Centre of earth.
Just over half earths radius
Inner core solid (compressed liquid), outer core liquid
What are tectonic plates?
Big interlocking jigsaw pieces on surface. Less dense than mantle
What happens when plates move?
Move 2.5 cm per year
Causes volcanoes and earthquakes
How are seismic waves made?
Earthquakes or man made explosions
Used to study earths structure
What are seismic waves used for?
By measuring the time it takes for different waves to travel you can tell if the wave has been through solid or liquid and get information about the structure of the earth
P waves travel through solids and liquids
S waves travel through solids (mantle)