CT 2 Flashcards
The inner core
- The centre of the earth.
- Solid.
- Made up of iron and nickel
- Hottest part of the earth.
- Up to 5,500°C.
The outer core
- The layer surrounding the inner core.
- Liquid.
- Made up of iron and nickel.
The mantle
- The thickest section of the Earth at approximately 2,900 km.
- Made up of semi-molten rock called magma.
- Upper part is hard.
- Lower part is soft & starting to melt.
The crust
- Outermost layer of the Earth.
- Thin, 0-60 km thick.
- Solid.
- The layer on which we live.
- Either continental or oceanic.
Continental crust
The surface of the Earth’s crust found underneath large land masses.
Continental crust thickness
60 + km
Continental crust composition
Granite
Continental crust density
Less dense
Oceanic crust
The surface of the Earth’s crust found underneath the oceans, forming the ocean floor.
Oceanic crust thickness
6 - 10 km
Oceanic crust composition
Basalt
Oceanic crust density
Dense
Plate margin
The region where two or more tectonic plates meet. It is a zone of intense seismic activity.
The theory of convection
Suggests that magma is rising in the mantle as it is heated and then sinks back down towards the core when it cools.
What is the earths crust made up of?
Large tectonic plates that are in constant slow motion.
Destructive plate margin
When two tectonic plates move towards one another. The oceanic crust is forced to sink back into the mantle, whilst the continental crust rises above. Volcanoes and earthquakes are found here.
Subduction
When one crustal plate is forced beneath the other.
Constructive plate margin
An area where two tectonic plates are moving away from one another.
Conservative plate margin
Areas between two crustal plates that are moving past each other in opposite directions or at different speeds.
