Evaluation of Lg as a Discriminant among Different Continental Crustal Structures

Lg is a useful discriminant among different continental structures. The group velocities and periods of the Lg stationary phases are diagnostics for crustal thickness and S-wave velocity, and for the velocity of Sn. Lg is insensitive to variation in the lid thickness and the S-wave velocity in the low-velocity zone; it is not a discriminant for the existence of a lid-low-velocity zone structure in the mantle. Examples of the discriminatory capabilities of Lg are given in both the frequency and time domain.