Efficient 2D shear-wave velocity subsurface profiling via passive multi-component seismic data.

Area of Science:

• Geophysics
• Seismology
• Earth Sciences

Background:

• Reconstructing 2D subsurface shear-wave velocity (V_S) structures using surface seismic methods is challenging due to limited depth penetration and non-uniqueness.
• Passive seismic methods offer potential but require robust analysis techniques for accurate subsurface imaging.

Purpose of the Study:

• To present an efficient technique for joint acquisition and analysis of multi-component passive seismic data for robust 2D V_S models.
• To introduce the 2D SuPPSALA (2D SUbsurface Profiling via Passive Surface-wave data Analysis from Linear Arrays) method.

Main Methods:

• Combines surface-wave dispersion from moving subarrays with station-specific spectral ratios in a unified joint inversion framework.
• Utilizes multi-component passive seismic data from linear arrays (3-component nodes or cabled systems).

Main Results:

• Successfully generated a 2D V_S model in a shallow perilagoon environment with abrupt lateral variations.
• Clearly imaged palaeodunes and palaeochannels, correlating low velocities (<100 m/s) with peat and high velocities (>300 m/s) with sandy deposits.
• Independent electromagnetic data validated the seismic profile, confirming mutual agreement.

Conclusions:

• The 2D SuPPSALA method provides enhanced depth sensitivity and reduced ambiguity compared to conventional techniques.
• The methodology is efficient, relies on simpler field operations, and is applicable to kilometer-scale profiles.