Scales used to measure earthquake intensity

Question 1

RICHTER SCALE

Answer 1

Scale: 0-9
METHOD: uses earthquake distance and wave amplitude

Question 2

ADVANTAGES OF RICHTER SCALE

Answer 2

1) allows medium earthquakes to be measured
2) simple
3) corresponds with observable damage

Question 3

DISADVANTAGES OF RICHTER SCALE

Answer 3

1) underestimates energy released in earthquakes with magnitude below 6.5
2) doesn’t give any indication of the total energy released by event

Question 4

MOMENT MAGNITUDE SCALE

Answer 4

Scale: 0-9
METHOD: measures size of events in terms of how much energy is released

Question 5

ADVANTAGES OF MOMENT MAGNITUDE SCALE

Answer 5

1) calculated values can be easily compared to other events
2) it takes into account other factors, e.g. rock rigidity
3) gives reliable estimate for earthquake size - accurately represented

Question 6

DISADVANTAGES OF MOMENT MAGNITUDE SCALE

Answer 6

1) bad for measuring small earthquakes
becomes inaccurate for events below 3.5

Question 7

MERCALLI SCALE

Answer 7

Scale: I - XII
METHOD: uses observations of people who experienced the earthquake to estimate its intensity

Question 8

ADVANTAGES OF MERCALLI SCALE

Answer 8

1) allows for the true impact of earthquake to be measured
2) a more meaningful measure, based on experience
3) different impacts taken into account, people experience different amounts of shaking in different places

Question 9

DISADVANTAGES OF MERCALLI SCALE

Answer 9

1) subjective
2) takes some time to measure as impacts of earthquakes happen over a period of time - there can be aftershocks days later