Oil trajectory analysis for oil spill surveillance by SAR in the Mediterranean Sea

Abstract

Oil trajectory analysis (OTA) provides statistics of direction and distance of provenience of oil spills reaching specific coastal sites. Applied to marine protected areas (MPA), this information could be used to introduce priority criteria in satellite oil spill surveillance. OTA in the Mediterranean Sea was based on 10-days oil trajectories tracked backward-in-time for five years (2015-2019) and aggregated on monthly basis. On average, travel time increases from 12 h at 5 km from the coast to 1.5 days at 10 km and 2 days at 15 km. The beaching probability decreases from 25 % at 5 km to 8 % at 10 km and 5 % at 15 km. Locally, the oil transport is influenced by persistent winds and/or energetic current systems in the area. Using an attention threshold of 5 % of beaching probability around MPA, several offshore areas of the Mediterranean Sea deserving high monitoring priority in summer and winter have been identified.

Keywords: Backtracking; Marine protected areas; Mediterranean Sea; Oil pollution; Oil spill surveillance by SAR; Oil trajectory analysis.