Which one of the following statements regarding the earthquakes are correct?
1) The intensity of earthquake is measured on mercalli scale
2) The magnitude of earthquake is a measure of the energy released.
3) Earthquake magnitudes are based on direct measurements of the amplitude of seismic waves.
4) In the Richter scale,each whole number demonstrates a hundred fold increase in the amount of energy released
1,2 and 3
2,3 and 4
1 and 4
1 and 3
A. 1,2 and 3