They are refracted slightly as they pass the boundary between the mantle and the liquid outer core.
They are refracted slightly as they pass the boundary between the mantle and the liquid outer core. These longitudinal waves can travel through gases, liquids, and solids. They can provide an early warning for deep, distant earthquakes,  arriving up to a minute before other destructive waves. FTP, name these seismic waves that travel faster than S-waves.
They are refracted slightly as they pass the boundary between the mantle and the liquid outer core.
P-waves  (primary waves)