GEOL463
VibroSeis source
Rather than using explosions, acoustic energy can be
distributed in time by using a hydraulic vibrator device
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Usually mounted on a heavy truck
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Small borehole vibrators, portable vibrators, and >100-ton
stationary vibrators also exist.
The signal consists of a quasi-monochromatic “sweep” of
gradually changing frequency, covering ~20-150 Hz
To produce stronger signal, vibrators are able to operate
synchronously (vibrate in-phase) in a group
The signal sent into the ground is carefully recorded and
afterwards “correlated” with the recordings to produce an
equivalent of impulsive excitation