Where and why do earthquakes occur?
- Earthquakes occur at Plate margins
- At Destructive plate margins - pressure of the subducting and melting plates are release and cause a powerful earthqake
- At Constructive boundaries - tend to be less severe The friction cause by the plates moving apart causes an earthquake
- At Conservative plate margins - greater strength, the plates slide past each other and stick for periods of time which causes stress and pressure to build. The release results in an earrthquake
The Richter scale - Every time the scale increases by 1 it means the volcanos strength has increased by 10.
The Mercalli Scale -
I - barely felt
V - felt by almost eveyone people sleeping are awakened
VII - considerable amount of damage to weak structures , most people run outside
X - Few structures survive, most foundations destroyed, avalanches flooding ect.