SEISMIC WAVE SPEED (VELOCITY) DEPENDS ON ELASTIC CONSTANTS (MODULI) AND DENSITY
– BULK MODULUS – LARGER IS HARDER TO COMPRESS
– SHEAR MODULUS – LARGER IS HARDER TO SHEAR
– DENSITY
COMPRESSIONAL (P) WAVE SPEED VP DEPENDS ON BOTH MODULI
SHEAR (S) WAVE SPEED VS DEPENDS ON SHEAR MODULUS
P WAVES TRAVEL FASTER (ABOUT 1.7X ) THAN S WAVES
S WAVES CANNOT TRAVEL THROUGH LIQUID ( = 0) LIKE OUTER CORE