About one-half of the oil in the ocean comes from natural oil seeps. Marine chemist and Coastal Ocean Institute Director Chris Reddy studies oil that is naturally seeping into the oceans in order to better understand accidental oil spills. This illustration shows the route traveled by oil leaving the
subseafloor reservoir as it travels through the water column to the
surface and ultimately sinks and falls out in a plume shape onto the seafloor where it
remains in the sediment.
(Illustration by Jack Cook, Woods Hole Oceanographic Institution)