Earthquakes Flashcards
What is the focus and the epicentre of an earthquake?
Focus - the actual place where the plates move under the ground
Epicentre - point directly above the focus on the surface
What is a seismometer?
What is a seismograph?
Seismometer - the instrument that measures the movement
Seismograph - the drawing which shows the earths movement
What scale measures the strength of an earthquake?
The Richter scale
What is the magnitude?
The strength of the earthquake
How are earthquakes distributed over the earth?
It’s an uneven distribution. They’re mainly located in the Pacific Ocean in linear patterns.
What are longitudinal waves?
What are transverse waves?
Longitudinal - cause an up & down movement
Transverse - cause side to side movement which cause more damage
Describe the Mercalli scale
It measures the damage done and it has 12 levels. As the level increases, so does the damage caused. It’s an arithmetic type (goes up 1,2,3 etc)
Compare Richter scale and Mercalli scale
Both measure strength of earthquakes. Mercalli measures by observation of damage done, less accurate because people will think differently. Richter scale measures energy of earthquake which is accurate m.
Describe the Richter scale
It measures the energy/magnitude of earthquake. It has nine levels. It’s logarithmic is scale so each level is 10 times stronger than the previous. It’s very accurate
State some Haiti earthquake primary effects
- 220,000 people dead
- 300,000 injured
- main port badly damaged
- hospitals destroyed
- 100,000 houses destroyed
- 200,000 houses damaged
- 1.3 million Haitians were homeless
Describe some secondary effects of the Haiti earthquake
- over 2 million Haitians left without food and water
- homeless people moved into tents and temporary shelters
- frequent power cuts
- many dead bodies in streets which created health hazard because of heat
What were the responses to Haiti earthquakes?
- clearing debris and rebuilding
- USA sent $100 million in aid
- UN fed 2 million people
- bottled water and water purification tablets given to survivors
- temporary hospitals set up
Describe effects of Chile earthquake
- 500 killed - 12,000 injured
- some buildings destroyed
- several roads destroyed
- 1 hospital destroyed
- communication damaged
- copper mine damaged (economic impact)
Responses to Chile earthquake
- president was organised quickly
- 10 days after earthquake 90% of homes had power and water back
- Chile was able to recover quickly
What’s the difference between immediate and long term response?
Immediate response is the help and reconstruction that happens straight after the disaster (eg: emergency water, food, sanitation supplies). Long term is the reconstruction that happens in the months/years that follow the disaster (eg: rebuilding)
