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AMO/QO Physics Seminar


"The redistribution of Petroleum Hydrocarbons in the deep water of the Gulf of Mexico during and following the Deepwater Horizon accident in 2010"


Dr. Norman L. Guinasso, Jr.
Department of Oceanography
Geochemical and Environmental Research Group
Texas A&M University


ABSTRACT 

In 2010 the Macondo well blowout released an unprecedented amount of oil into the deep waters of the Gulf of Mexico. A large amount of this oil remained in the deeper waters mostly likely because dispersants were injected directly into the flow at the wellhead in water 1500m deep. This oil in the deeper waters was redistributed by deep ocean currents. A major driver of the deep currents is the flow of the Loop Current through the Yucatan Straits and the mesoscale eddies that detach from this flow. The mesoscale eddies represent high and low pressure regions in the ocean. Currents flow counter-clockwise around high pressure eddies and clockwise around low pressure ones. These eddies have a scale of order of 100km and propagate westward through the Gulf. Currents in these eddies can reach 1-2 m/s and extend deep into the ocean at lower velocities. High pressure eddies can raise sea level 10’s of cm above the geoid. Our knowledge of the deep currents is informed by satellite altimeters which can measure the sea surface height to precisions approaching 1cm. Satellite altimetry during the incident revealed the Loop Current breaking off to form a warm core ring. Measurements made by TAMU scientist during the spill indicate that very tiny amounts of the oil may have been entrained in this eddy. During the spill over 30,000 water samples were collected and analyzed for petroleum chemical species. BP has published an online database of these measurements. I will present my analysis of this data which show high concentrations in the deep waters during the spill extending 50-100 km from the release site. These levels drop quickly toward background levels after the end of the release.


Wednesday, June 10, 2015
IQSE 578, 2:00 PM
Mitchell Physics Building


Department of Physics
Texas A&M University



Host: Dr. Hans Schuessler