Sediment Profile Imaging (SPI)
Sediment Profile Imaging (SPI) is used to create underwater photographs of the interface between the seabed/riverbed and the overlaying water. The camera is mounted vertically within a waterproof housing. Photos are acquired through a 45º angle prism which provides a horizontal, cross-sectional photo of the upper ~20cm of the surface sediment. The SPI camera is deployed at aquatic disposal sites, construction sites, and sediment cap locations to provide before- and after-activity conditions, or Superfund sites for sediment assessment or simply to limit direct human interaction with the sediment.
SPI images may be analyzed to determine sediment type, to evaluate the in situ chemical REDOX state of the surface layers (through color analysis), and to evaluate benthic ecological cycling in surface sediments (e.g. presence of organisms, and evidence of bioturbation, and/or bio-irrigation). The camera view frame is scaled; therefore, the imagery can be used to perform in situ measurements of layer thickness, benthic community characterization, and sediment grain size.
OSI supports clients engaged in contaminated sediment site remedial investigation/feasibility study (RI/FS) activities, environmental risk assessment, biogeochemical modeling, and sediment cap monitoring.