Datation of oil spills, St Brieuc wind farm site, Brittany, France

Sentinel-1 CSAR IW acquired on 08 June 2021 at 17:57:18 UTC
Sentinel-3 OLCI FR acquired on 13 June 2021 at 10:56:06 UTC
Sentinel-2 MSI acquired on 13 June 2021 at 11:21:11 UTC
Sentinel-1 CSAR IW acquired on 14 June 2021 at 17:56:25 UTC
Author(s): Sentinel Vision team, VisioTerra, France -
Keyword(s): Oil spill, pollution, marine environment, emergency, man-made disaster, ship, Normandy, France, Channel
Fig. 1 - S1 (14.06.2021 17:56) - The ship Aeolus declared that it had leaked 100 litres of oil.
The oldest part visible on the spill has likely been emitted 17 (conservative estimate, red) to 20h (lower confidence estimate, yellow) before.
Fig. 2 - S1 (13.06.2021 18:03) - Several tide cycles indicate this slick is ~18-21h old, 40 to 47 km long depending on the confidence level.
To be made of 62 200 m high turbines, the first eolian park of France is being constructed by the Dutch ship Aeolus. The site was however affected by an oil spill declared at 6:30 am on Monday 14 and estimated by the authorities as 16 km long.
Fig. 3 - S2 (13.06.2021 11:21) - This is the same slick 7 hours before the previous image, visible in the sun glint.
According to the tidal charts, it can be estimated at 15h old, it is coherent with the above estimate. Darker areas at south west are difficult to estimate reliably.
Fig. 4 - S3 OLCI (13.06.2021 10:56) - The same spill, not seen in the sun glint, can be found to be between 14h and 26h old.
Fig. 5 - Landsat-8 (12.06.2021 10:58) - The three cyan lines show 3 slicks at north-west, the oldest slick must be over 24h old.
Fig. 6 - S1 (08.06.2021 17:57) - This image shows Aeolus was already causing a significant leak one week before the declaration.