There are 3 types of rocks.

Igneous

• Igneous is made when magma rises from the mantle.
• Under the surface ,it slowly cools and hardens.
• This is known as intrusive rocks .
• Example Granite .
• Above the surface , it hits the cool air and hardens .
• This is known as extrusive rock. Example Basalt.

The next rock is called Sedimentary rock .

• Rocks on the earth's surface are worn down over time .
• Some broken pieces of rock make their way down to the sea.
• They become compressed and cemented and mixed with dead Sea creatures .
• They form... (More)

• Earthquakes -sudden shaking of the earth caused by the movement of the crust.
• Tremors -vibration.
• Focus- the point under the surface where the earthquake happens.
• Faultline -the line of two plates.
• Epicentre - the point on the surface directly above the focus. The earthquake is the strongest here.
• Seismic waves -waves of tremors.
• Aftershock- smaller tremors that come after the earthquakes.
• Seismologist - a person who studies earthquakes
• Seismographs - an instrument that measures the strength of an earthquake.
• Richter scale - measures the strength of an earthquake .it goes from 1-8
• Moment Magnitude Scale (MMS) - measures the... (More)