Earthquakes

Question 1

What are earthquakes and how are they caused?

Answer 1

• Earthquakes are a seismic event resulting from tectonic movement
• They are caused by tension that builds up at all types of plate margins
• When plates violently jerk past each other, it causes an earthquake due to vibrations
• The shock waves spread out around the focus, and the earthquake gets weaker the further way it is from the focus

Question 2

How is an earthquake measured?

Answer 2

• Measured on the Richter scale
• It has no upper limit and is logarithmic, meaning for each stage it increases, its power is 10x the previous stage. E.g. An earthquake with a magnitude of 5 is 10 times greater than one with a magnitude of 4
• The Mercalli scale measures the impacts of an earthquake using observations of the event
• Scale is between 1-12
• 1 being only detected with instruments and 12 being total destruction