Enhancing low-frequency water-column acoustic reflections in marine multichannel seismic data for seismic...

Area of Science:

• Marine geophysics
• Oceanography
• Acoustics

Background:

• Marine seismic surveys traditionally collect, but underutilize, weak water-column reflections due to low acoustic impedance contrast.
• The emerging field of seismic oceanography aims to leverage these reflections for imaging ocean structures.

Purpose of the Study:

• To investigate the acoustic multipath structure of marine seismic data, specifically focusing on water-column reflections.
• To develop and validate a novel method for enhancing water-column reflections and suppressing interfering bubble waves for improved oceanographic imaging.

Main Methods:

• A two-step matched filtering approach was developed to enhance water-column reflections.
• The method was applied to seismic data from the Gulf of Mexico.
• Performance was evaluated by comparing results with traditional matched filtering techniques.

Main Results:

• The new approach significantly improved the imaging of mesoscale ocean structures.
• An 11.3-dB increase in signal-to-noise ratio was achieved by noise removal.
• An 8-dB improvement in signal-to-reverberation ratio was obtained by suppressing bubble waves, preserving oceanographic information.

Conclusions:

• The study provides valuable insights into the characteristics of water-column acoustic reflections.
• The developed method offers enhanced tools for acoustic imaging of mesoscale ocean structures using seismic data.