Earth's Structure Flashcards
The Crust
The crust is the outer layer of the earth which is made of solid rock
The crust is up to 60km
The Mantle
This is the middle layer of the earth
It is made up of molten(melted) and semi-molten rock called magma
The temperature in the mantle reaches 4000º
The Core
The core is the centre of the earth and is made up of 2 parts
(Inner core & Outer core)
The Outer Core
It’s made mostly from iron & nickel and is molten(molten liquid)
The Inner Core
It’s solid due to pressure
The temperature in the core is estimated to be over 5000º
The Earth’s Plates
Earth’s crust is broken into big pieces.
These pieces are called “Plates”
The edge of the Plates are called “Boundaries”
7 main Plates
African Plate American Plate Eurasian Plate Australian Plate Nazca Plate Indian Plate & Pacific Plate
Plate boundaries
These plates sit on top of semi-molten rock or magma in the upper mantle.
Convection Currents
The magma is moved around in circular movements by convection currents which causes Plates to move.
Convection Currents (How it works)
When magma is heated in the mantle it rises upwards.As it rises, it cools and sinks back down into the mantle in circular movements
Continental Drift
Movement of Plates
Study of Plates
Plate tectonics
Pangaea
225 million years ago all the continents footed into one large continent.
Destructive Boundaries
This is Plates which collide into each other
These cause fold mountains (Eg. The Andes,South America) volcanic mountains and earthquakes
Constructive Boundaries
This is Plates that separate from each other
These cause volcanic activity that results in volcanoes,volcanic islands (eg. Iceland) and mid ocean ridges ( eg. Mid Atlantic Ridge)
