A Very Low Frequency Marine Vibrator

Summary There has been an increasing interest in the industry for powerful very low frequency (VLF) seismic sources. The lowest frequency range is important for deriving the elastic properties of the subsurface by seismic full wave field inversion (FWI). Accordingly, there has been a need for powerful low frequency marine sound sources operating in the frequency band of 1 to 5 Hz. This paper describes a new low frequency source that is easy to deploy and operate from a small vessel. The new very low frequency source is built on a novel source concept using resonance to increase acoustic efficiency and at the same time decrease complexity of the source. The resonance frequency of the source can easily be adjusted to a certain frequency or adaptive in case of running sweeps in the frequency band of 1 to 5 Hz. This less complex source can be deployed at a water depth of 5 m or less and will give a SPL of more than 190 dB rel. 1 micro-Pa in the frequency range from 2 to 5 Hz.