Vibroseis

OBS: Vibroseis : Dénomination d'un procédé de sismique réflexion utilisant l'envoi d'une onde entretenue à l'aide d'un vibrateur.

CONT: ... there is vibroseis, a system which ... employs a non-impulsive source. The vibroseis transmitters are like huge loud-speakers with their diaphragms pressed against the ground ... The smaller models are electromagnetic like their radio counterparts, while the larger ones are operated hydraulically. The message which they transmit into the ground is a wave train of varying frequency ...