Mitigating Shallow Subsurface Risk with Marine Electrical Resistivity Tomography (MERT)

This paper presents the application and advantages of Marine Electrical Resistivity Tomography (MERT) for mitigating shallow subsurface risks in maritime developments. The rapid expansion of maritime infrastructure necessitates detailed subsurface characterization, which is often challenged by limitations in traditional geophysical methods. This study highlights the capabilities of MAPPEM's 2D MERT system, a non-invasive technique that provides continuous resistivity profiles in offshore and nearshore areas. The system, towed near the seafloor, utilizes a dipole-dipole electrode configuration and inhouse and off-the-shelf inversion algorithms to generate 2D subsurface resistivity images. Key advantages of MERT include its ability to penetrate all lithologies without masking effects, differentiate lithology, detect objects, and image through acoustic masks, as demonstrated through examples involving calcarenite and shallow gas imaging. Furthermore, the paper discusses the potential of MERT in characterizing clay-rich areas, which is crucial for optimizing cable routes and foundation designs. By integrating resistivity data with other geodata, MERT enhances subsurface understanding, reduces project uncertainties, and facilitates the development of reliable ground models. This research underscores MERT's potential as a valuable tool in site investigation programs, contributing to the safe, efficient, and sustainable implementation of maritime projects.