Oil Spills

Deep Water Horizons

I’m McKensie Daugherty, your host for on the ocean. Did you know the ocean has many natural oil seeps? Oil is constantly being released from the sediments into the water column in the world’s oceans. This oil is normally taken care of naturally by bacteria, so other organisms living there are not harmed. The trouble with oil in the ocean occurs when oil is introduced into the ocean by human impacts (such as oil spills, and runoff from stormwater systems). On April 20th, 2010 the Deepwater Horizon drilling rig experienced an explosion that engulfed the platform, killing 11 and injuring 16 people. This explosion led to the drill rig sinking, as well as a long-term leak of oil and gas from the well. This leak at 1500 meters depth presented a problem, in that it was technically extremely difficult to attempt to cap the well. Because this leak was so deep, several attempts to cap it failed, so that the leakage of crude oil into the water column of the Gulf of Mexico continued for 3 months. In total, the well leaked 700,000 tons of oil and a quarter of a million tons of methane into the ocean, and the surface slicks that resulted coated 626 miles of coastline with crude oil and an oil/water emulsion called mousse. The spill closed most of the northern Gulf of Mexico to fishing, and was so serious that the national guard was called out to help. Overall, this and other oil spills can be incredibly detrimental to ocean life. This month we will go into why oil spills are deleterious, how to help clean them, and what researchers at Texas A&M are doing to understand these events better. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Piers Chapman

http://gisr-consortium.org/

Oil in the Ocean

I’m McKensie Daugherty, your host for On the Ocean. Oil leakage in any ocean can either be incredibly harmful, or totally normal phenomena depending on the amounts and souces of oil and gas being introduced into the water column. Oil spilled from wells in the deep ocean breaks up into droplets of sizes that vary depending on oil type and the turbulence within the flow from the wells. These droplets rise together in a vertical plume that eventually is trapped by the layered density structure of the ocean. Droplet size and their flow rate determine what impacts oil spilling in the ocean can have. Smaller oil droplets are affected by inner ocean turbulence, and can become trapped in what’s known as an intrusion layer below the water surface at the top of the plume. Dissolved hydrocarbons and small oil droplets sequestered in the intrusion layer can then be degraded by bacteria in the water column. Larger oil droplets rise to the sea surface because the internal ocean turbulence is not strong enough to keep them in an instrusion layer. When oil reaches the surface, wind and waves can carry the oil to the shore where it causes arguably the most harm and most likely comes in to contact with humans. This is where dispersants come in. Dispersants are chemicals used to break up larger oil droplets into smaller ones and either keep them in the intrusion layer or force them to mic onto the upper layers of the water column instead of remaining as a solid layer on the surface. In either case, the effect of oil on the shoreline is reduced. Many factors affect oil droplet size, and researchers at Texas A&M University are trying to understand them using controlled experiments and the use of computer models. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Scott Socolofsky

http://gisr-consortium.org/

http://gisr-consortium.org/

I’m McKensie Daugherty, your host for on the ocean. Today we dive back into the Deep Water Horizon spill, and the efforts to clean it before it impacted the Gulf of Mexico. The well at the Deep Water Horizons spilled up to 60,000 barrels of crude oil per day, according to the government’s estimate. In this oil spill, a high priority is cleaning up the oil spilling out before it reaches a shore. Many tactics are used during oil spill cleanup, including dispersants, booms, and controlled burns. Some components of oil dissolve naturally, while dispersants are chemicals used to break up the oil into smaller droplets which encourages further break down by the bacteria. In either case the oil cannot get to the shore where it does the most damage. Nearly 2 million gallons of dispersants were used during the Deep Water Horizon spill to try and reduce the amount of oil headed to shore, including the first use of dispersants at depth during a spill. Booms are large floating barriers used to contain oil spills. 2,000 miles of boom were used in the cleanup of the Deep Water Horizons spill, mainly to try and keep oil off the shoreline. The National Guard deployed 44,000 people for cleanup, while 6,000 ships were also used for various activities, including boom and dispersant deployment. Dispersants need mechanical energy to work its best, so high wave activity is necessary. This was a problem in the Gulf at the time of the spill, so the mechanical energy was provided by the churning water caused by the boats working in the area. You can also try burning the oil floating in the ocean, and there were 400 controlled burns during the cleanup effort. Overall, thousands of people were involved in attempting to control this oil spill and save the shoreline. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Piers Chapman

http://gisr-consortium.org/

Texas A&M Researchers on Oil Spills

I’m McKensie Daugherty, your host for on the ocean. Oil spills like the Deep Water Horizon event cause massive disruption to marine ecosystems and economies. Therefore, many institutions study these events to better understand why they happen, and what the best ways are to control and clean them. Researchers at Texas A&M University were a part of these projects with experiments to learn how future oil spills move in the ocean and what this means for their ability to predict how oil spills will move in the Gulf of Mexico. One experiment involved putting a non-harmful tracer compound into the ocean and then measuring where it ended up after certain times. This way, scientists can track the dynamics and movement of molecules similar to crude oil and the direction and how quickly they move in the ocean. This experiment also allowed scientists to check their computer models of circulation for validity, and gain additional samples from longer-term current meter moorings. The regional models created and used by Texas A&M scientists have many ranges of scales, from 10-50 meters resolution within Galveston Bay, to several kilometer resolution throughout the entire Gulf of Mexico. They have also created models at the molecular scale to understand oil droplet movement. By incorporating data in their models, researchers can test them to understand how and why oil moves across the Gulf of Mexico, and predict where oil from any future spill might go, and the ecosystems and economies the oil will affect. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Piers Chapman

http://gisr-consortium.org/