Relationship between resistivity and physical properties of seafloor sediments in the hydrate production test area of the South China Sea

The vast distribution, abundant reserves, and high combustion utilization rate of natural gas hydrate make it an appealing alternative energy source. Nevertheless, the special physical and mechanical properties of the hydrate production test area in the South China Sea have led to frequent geological disasters, requiring monitoring and early warning of potential geohazards. To facilitate this process, a model was established to determine the relationship between sediment resistivity and physical properties in this area. However, there is currently no suitable sediment resistivity inversion model for this region. We obtained an 8 m-long core sediment sample from the hydrate production test area in the South China Sea using a core sediment sampler aboard the research vessel "Marine Geology 6". Indoor geotechnical tests were conducted to determine the vertical variation characteristics of the sediment, and indoor resistivity tests were performed to obtain its resistivity vertical variation. Using empirical power function formulae, we established a relationship model between resistivity and physical properties, which we then compared with relevant data from nearby sea areas. This model lays the foundation for using in situ resistivity to invert the dynamic changes of sediment physical properties and promote the development of deep-sea engineering geology.