Read the following passage and select the option which correctly fill blanks (i), (ii), (iii) and (iv).
(i) is the point of origin of an earthquake. (ii) measures the strength of an earthquake by estimating the amount of energy released at the focus. The point vertically above the origin point on the surface of the Earth, is (iii) . Seismic waves are detected, recorded and measured by (iv) .
Itâs seismograph that measures the strength of the earthquake.