Modelling oil trajectories and potentially contaminated areas from the Sanchi oil spill.

ABSTRACT

Oil spills are major threats to marine ecosystems. Here, we establish a three-dimensional oil spill model to simulate and project the short- and long-term trajectories of oil slicks and oil-contaminated water that leaked from the Sanchi wreckage. The pollution probability in surrounding areas for the period up to 180 days after the Sanchi sank is statistically analysed. The short-term simulations are consistent with synchronous SAR images and observational reports. The potentially polluted areas depend on the properties of the released oil. The coastal areas most likely to be affected by the bunker oil are located in the Ryukyu Island Chain, Tsushima Strait, on the south and east coasts of Japan. Approximately 50% to 70% of oil particles remain in the ocean and mainly expand along the Ryukyu Island Chain and the region southeast of the Sanchi wreck. Subsurface oil-contaminated water is likely to enter the Sea of Japan along the Tsushima Strait. Due to the rapid evaporation rate of condensate oil, the potentially polluted area is confined to regions within a 100 × 100 km area around the location of the shipwreck, and the contaminated region is closely associated with the surface wind.