The Semblance plug-in is used to pick velocity-time pairs and ETA-time pairs based on hyperbolic searches for coherence between multiple seismic signals in migrated gathers. The goal of this utility is to provide a robust velocity analysis to aid in further iterations of migration. In Tsunami’s Semblance Builder, the user is capable of picking both RMS and ETA semblance simultaneously, with instantaneous on-screen updates of the flattened gathers. With the Semblance utility, the user can choose to output an RMS velocity model and/or an ETA model of interpolated Semblance picks.