This is a time sequence of the simulated 3-D spatial distribution of oil products below the surface based on current advection and oil buoyancy in the region. The color-bar indicates the size of individual oil droplets for the hypothetical scenario without deep injection of dispersant. The formation of the prominent deep hydrocarbon plume (blue) and the layering of shallower plumes demonstrates that chemical dispersants injected at the wellhead were likely not effective in changing the amount of oil reaching the surface. These findings appear in a new article in Environmental Science and Technology. The oil in the top 20 m of the sea surface is not shown (e.g., transport of oil reaching the surface is not depicted).