Earthquakes do not at depths greater than 720km because deeper, warm rocks are not enough to so do not occur.

The S wave shadow zone is found at:
degrees to degrees.
The P wave shadow zone is found at:
degrees to degrees.

Focus = The point the Earth at which the earthquake originates.
= the point on the Earth's surface, directly the focus and shows where the greatest amount of is likely to occur.

Isoseismal line = A on a map which joins up points of equal , separating zones of different intensities.

Mercalli Scale:
- Measures the of an earthquake based on the felt in a particular area.
- It is a point scale.

Richter Scale:
- Measures the of an earthquake by recording the of seismic waves.
- The values are then converted into a scale.

Earthquakes occur in solid, , competent rocks as they suddenly and move relative to each other.
The seismic energy is transmitted through the rocks as seismic .

Weak incompetent rocks steadily under stress by folding or plastic flow. They do not so earthquakes cannot occur.

The of seismic waves is larger in unconsolidated sediments resulting in greater to buildings.
In consolidated sediment the seismic waves are .

Physical effects of earthquakes:
Ground
Damage to
L
Land
After
T

Social and economic effects of earthquakes:
Infrastructure and c damaged affects how quickly people can respond to effects of earthquake.
Damaged water pipes can affect supply of clean water and lead to risk of disease spreading.
D and i of people impacting families.
Loss of p supply.

How do earthquakes cause tsunamis?

A large of water is displaced as a result of the earthquake being at a shallow depth below the sea.