What are the Earth’s 3 layers?
- crust = made up of rocks
- mantle = made up of rocks
- outer core = made up of metals
- inner core = made up of metals
What are the 2 types of tectonic plates AND features?
- continental = thicker, older and less dense
- oceanic = thinner, younger and denser , so they get subducted under other plates
What is the place where 2 plates meets are called?
plate margins
Describe convection currents?
- occurs in the upper mantle
- allows plates to move when the heated molten rock rises
What happens at a constructive plate margins?
- 2 plates moves away/ diverge from each other
What happens at a conservative plate margins?
- 2 plates slides past each other EITHER at:
- the same direction but different speeds
- or in opposite direction
What happens at a destructive plate margins?
- 2 plates move towards each other
What happens when there two continental plates at a destructive plate margin?
- they collide and fold upwards
What are earthquakes?
vibrations caused by earth movement at plate margins
What are the different aspect of an earthquake?
- focus
- epicenter
- seismic (shock) waves
What is the focus?
the point where there is movement in the earth’s crust
What is the epicenter?
directly above the focus on the earth’s surface
What is the seismic waves?
starts at the focus
What scale do we use to measure an earthquake?
the Richter scale which is measure on a seismometer to record the earthquakes magnitude
The Richter scale is logarithmic , what does that mean?
the scale goes up in 10s (so 2 on the scale is 10 x stronger than 1)
Name and explain the 3 reason why people live in areas at risk of tectonic hazards?
- geothermal energy = cheap renewable power & hot water attract business
- tourism = beautiful scenery, hot springs so it creates need for hotel shops and service
- farming = fertile soil -due to the minerals in volcanic ash & lava- which can produce high crop yield
