Researchers at the Woods Hole Oceanographic Institution (WHOI) have detected a plume of hydrocarbons that is at least 22 miles long and more than 3,000 feet below the surface of the Gulf of Mexico, a result of the BP Deepwater Horizon oil spill, reports a study published in Science.

The 1.2-mile-wide, 650-foot-high plume of trapped hydrocarbons provides a clue on where all the oil has gone as oil slicks on the surface disappear.