किस प्रकार की भूकंपीय तरंग पृथ्वी के तरल बाहरी कोर (liquid outer core) से होकर यात्रा नहीं कर सकती है?

Secondary (S) seismic waves cannot pass through liquids because:

Which of the following instruments is used to record the waves generated by an earthquake?

The place on the surface of the Earth vertically above the place of origin of an earthquake is called the: