Earthquakes

• Focus- point of origin of an Earthquake within the Earth’s crust
• Epicentre- The point on the surface which is directly above the focus and where the earthquake is felt the strongest.
• Seismic waves definition

  Shock waves that travel through the Earth’s crust.
• What to do during an Earthquake?

  • Protect your head
  • Remain calm
  • Move away from glass, pictures, bookcases, hanging plants and heavy objects
  • Watch for falling plaster/bricks, lighting fixtures and other objects
  • If in car, do not stop on a bridge, under electrical poles or building that might fall
• What to do after an Earthquake

  • Check for fires
  • Check utilities
  • Check for serious damage
  • Check for injuries
  • Prepare for additional shocks
  • Collect water
  • Clear up hazardous material
  • Assist others
  • Turn on a radio to listen to emergency bulletins
  • Stay away from prone landslides areas
  • Stay away from buildings that might have been weakened
  • Remain calm
• Who studies Earthquakes?


  Seismologist
• What instrument is used to measure the strength 


  Seismograph
• What instrument is used to measure the speed?


  Seismometer
• How are Tsunamis caused? 


  Due to an earthquake on the seafloor, the water becomes displaced creating a tsunami
• How tall can a tsunami get?

  30 m
• How fast does a tsunami move?

  500 m per hour
• Effects of tsunamis

  • Loss of lives
  • Destruction of whole villages
  • Damage to fishing boats, coral reefs and marina facilities
  • Flooding
  • Disruption to the economy
  • Destruction of crops and infrastructure
  • Intrusion of salt water into minerals
  • Flood and water shortages
  • Disease caused by contaminated water and unburied bodies
• Crater


  The depression at the top of the volcano, formed when the magma chamber empties during an eruption or by the collapse of the volcano's summit.
• Types of plate movements

  • Convergent plates
  • Divergent plates
  • Transform plates
• Convergent plates move towards each other.
• Convergent plate functions

  Volcano

  Mountains

  Earthquakes
• Transform plates slide past each other.
• Divergent plates moves apart
• Divergent plate functions


  Volcanoes

  New sea floor

  Earthquakes
• Transform plate functions


  Earthquakes
• There are three types of plate boundaries where two or more plates meet - convergent, divergent and transform.
• Plate tectonics include:

  Continental plate

  Oceanic plate
• Plate tectonics definition 


  Movement of pieces of solid Earth called plates which fit together like a jigsaw puzzle.
• Plate margin/boundries 


  The end of a plate. The area where two plates interact and can create new land forms.
• Earthquake 


  Unpredictable vibrations or sudden tremor occurring deep in the Earth’s crust.