The drift and spreading of the Runner 4 oil spill and the ice conditions in the Gulf of Finland, winter 2006

The drift and spreading of the Runner 4 oil spill in the ice-covered Gulf of Finland is analysed. The oil spill was caused by the sinking of the Dominican-registered cargo ship Runner 4 on 5 March 2006, after collision with the Malta-registered cargo ship Svjatoi Apostol Andrey. This oil spill was very difficult to detect in the first week due to severe ice conditions. Combating operations started when the wind pushed the ice floes away and the spill was observed in open sea areas. Two efforts were made to collect and control the oil spill, one during 15–19 March and the other on 9 April. A sea ice dynamics model is employed to simulate the evolution of the ice conditions. A comparison between the oil spill coverage and the sea ice movement suggests that part of the oil followed with the ice while the other part of it must have drifted together with the surface current. The observations also show that the oil was continuously leaking from the hole in the left side of the Runner 4, at least until 9 April.