**7. Conclusions and summary**

Oil Spills have never occurred on the North Carolina or South Carolina US continental margins. However, they have occurred in the Gulf of Mexico where a great many oil drilling platforms are located, and many oil tankers transit Gulf Waters daily. In 2010, there was a major oil spill in the Gulf. In 2017, the US administration lifted a ban on oil drilling in North Carolina Coastal waters. So two questions arise: One, could an oil spill in the Gulf reach Carolina coastal waters? Secondly, if an oil spill were to occur in the future off North Carolina, could it reach the beaches under typical environmental conditions? We address both questions.

To address non-local oil spills reaching the Carolinas, we revisit a Red Tide outbreak on the West Florida Shelf that reached the coasts of the Carolinas. In August 1987, a Red Tide occurred on the West Florida continental shelf off Naples, Florida. Those deleterious plants reached North and South Carolina shelf waters by late October. Using data from that era, we create a data-based scenario by which atmospheric conditions combined with oceanic currents carried the Red Tide plants over 1600 kilometers (1010 miles). Then based on the surrogate Red Tide plants, we numerically modeled the atmospheric and oceanic conditions of 1987 and dumped passive oil particles into the numerical model off Naples, Florida. The model predicted that the oil would have reached Carolinas coastal waters. Thus, we demonstrate from both data and numerical modeling that oil spills in the Gulf of Mexico have the potential to reach the US eastern seaboard via a combination of atmospheric storms, major ocean currents, and atmospheric wind-driven surface currents.

To address the possibility of a local oil spill reaching the beaches of the Carolinas, we consider the 2017 U.S. White House removal of an oil-drilling ban in North Carolina coastal waters. Herein, we released oil spilled in a projected oil drilling location on the North Carolina shelf into our atmospheric and oceanic numerical model. Again, given typical atmospheric and oceanic phenomena, the hypothetically spilled oil reached the beaches of North Carolina.

Thus, we have demonstrated that as a matter of a series of non-local and local atmospheric and oceanic phenomenological consequences, in outer continental shelf waters, oil in the upper 15 meters of the water column can be carried long distances and then driven toward the coast and reach the beaches. This is especially true during the passage of an atmospheric Extra-Tropical Cyclone. If a Gulf Stream Frontal Filament is present offshore, then during the passage of a cyclone event, oil in the upper 15 meters, even well offshore (~75 m deep) will be carried to the coast.
