Year 8 Geography Exam - Alun School...Revision PowerPoint Part 1 Natural Disasters What are natural disasters? •What is the difference between natural and man made disasters? •What

Year 8 Geography Exam

Revision PowerPoint

Part 1

Natural Disasters

What are natural disasters?

• What is the difference between natural and man made disasters?

• What is a geological disaster?

How is the Earth Structured?The structure of the EarthThe Earth is made up of four distinct layers:

• The inner core is in the centre and is the hottest part of the Earth. It is solid and made up of iron and nickel with temperatures of up to 5,500°C. With its immense heat energy, the inner core is like the engine room of the Earth.

• The outer core is the layer surrounding the inner core. It is a liquid layer, also made up of iron and nickel. It is still extremely hot, with temperatures similar to the inner core.

• The mantle is the widest section of the Earth. It has a thickness of approximately 2,900 km. The mantle is made up of semi-molten rock called magma. In the upper parts of the mantle the rock is hard, but lower down the rock is soft and beginning to melt.

• The crust is the outer layer of the earth. It is a thin layer between 0-60 km thick. The crust is the solid rock layer upon which we live.

• There are two different types of crust: continental crust, which carries land, and oceanic crust, which carries water.

Convection currents

Watch this:

https://www.youtube.com/watch?v=ryrXAGY1dmE

Destructive plate margins

You need to be able to draw and explain why volcanoes and

earthquakes happen at different plate margins.

What is missing?

Watch this:• http://www.bbc.co.uk/schools/gcsebitesize/geography/nat

ural_hazards/tectonic_plates_rev3.shtml

Plate tectonics song

• https://www.youtube.com/watch?v=hhxjAAnwNKM

Watch and sing ... Great revision!!!

Earthquakes

• Causes:

• Impacts:

• http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/earthquakes_rev1.shtml

Measuring earthquakes

Earthquake preparation:

• http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/managing_hazards_rev2.shtml

• https://www.youtube.com/watch?v=1s6hfbxb0EA

• https://www.youtube.com/watch?v=CXAgm2Tzd0g

• https://www.youtube.com/watch?v=nANnUNauD1c

Structure of volcanoes

• http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/volcanoes_rev1.shtml

Impacts of volcanoes

• Lava flows

• Ash clouds

• Pyroclastic flows

• Lahars

• Learn examples (e.g Mount Pinatubo, Mount St Helens)

Managing volcanoes

• http://www.bbc.co.uk/schools/gcsebitesize/geography/natural_hazards/managing_hazards_rev1.shtml