Love waves occur when there is a general increase of S- wave velocity with depth. The particle motion is transverse and horizontal. Generally, Love waves velocities are greater than Rayleigh waves. Love waves arrives first before Rayleigh waves on seismograph. This is how it was determined that the outer core consists of liquid.
Unsaturated sediments have lower values than saturated sediments.
Unconsolidated sediments have lower values than consolidated sediments. Velocities are very similar in saturated, unconsolidated sediments. Weathered rocks have lower values than similar rocks that are unweathered. Fractured rocks have lower values than similar rocks that are unfractured. The earthquake focus or hypocenter is the point where the earthquake originated.