A seismic monitoring station detects two distinct types of waves propagating through a uniform granite stratum from an underground tremor: a primary PPP-wave (longitudinal) and a secondary SSS-wave (transverse). Which of the following statements correctly describes a difference in their physical behavior?
Both the PPP-wave and the SSS-wave can be polarised because they are both mechanical progressive waves.
The SSS-wave can be polarised because its particle oscillations are perpendicular to the direction of propagation, whereas the PPP-wave cannot be polarised.
The PPP-wave can be polarised because its particle oscillations are parallel to the direction of wave travel, whereas the SSS-wave cannot be polarised.
Neither wave can be polarised because polarisation is a phenomenon that only applies to electromagnetic waves.