root-mean-square velocity

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root-mean-square velocity (Vrms) The velocity of waves through subsurface media down to the nth interface, such that Vrms = (ΣVint 2titi)½, where Vint and ti are the interval velocity and single-travel time through the ith interval. Vrms is usually derived from normal moveout measurements from a T2−X2 graph, and is commonly several percent larger than the corresponding average velocity.