Mysterious oil spill on Brazilian coast: Analysis and estimates

Highlights: • The oil spilled volume was estimated using weathering equations by model (STFM). • STFM is the Spill, Transport and Fate Model. • Spilled volume was considerably smaller than that of a full tanker. • The spill was possibly by buoyancy problems on the tanker losing its cargo part. In 2019–2020, a mysterious oil spill reached a large part of the Brazilian coast. In order to contribute to the clarification part of these mysteries involving this accident, the present study aims to estimate the initial volume spilled using the STFM (Spill, Transport and Fate Model). We started from the hypothesis that the leak was caused by tanker buoyancy problems (hull rupture or engine failure), resulting in slow loss of part of its cargo (leaking or dumping) in the subsurface waters. The estimated volume (5000–12,500 m³) was similar to that expected in a continuous leak from an internal compartment tanker with the size between PANAMAX and SUEZMAX. This volume may have been the largest oil spill on the Brazilian coast since 2004, and it caused institutional and socioeconomic crisis because of the poor management of public resources.