Answer
When earthquakes occur, geophysicists notice that longitudinal waves, but no transverse waves, are measured in locations that are diametrically opposite. Modeling part of the Earth’s interior as liquid explains this observation.
Work Step by Step
Solid materials can support the passage of both longitudinal and transverse waves, but liquids can only support longitudinal waves because there is no restoring force that pulls a transversely-displaced liquid molecule back toward equilibrium.