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'''<this is a terrible site
{{Redirect|Oil Slick|the Transformers character|Oil Slick (Transformers)}}
{{For|the 2010 oil spill in the Gulf of Mexico|Deepwater '''''Italic text'''drastic'' oil spill}}
[[File:Oil-spill.jpg|thumb|A beach after an oil spill]]
[[File:Oil Slick in the Timor Sea September-2009.jpg|thumb|right|250px|Oil Slick from the [[Montara oil spill]] in the Timor Sea, September, 2009.]]


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⚫
An '''oil spill''' is an unintentional release of a [[liquid]] [[petroleum]] [[hydrocarbon]] into the environment due to human activity, and is a form of [[pollution]]. The term often refers to [[Marine (ocean)|marine]] oil spills, where oil is released into the [[ocean]] or [[coastal waters]]. Oil spills include releases of [[crude oil]] from [[Oil tanker|tankers]], [[Oil platform|offshore platforms]], [[drilling rig]]s and [[Oil well|wells]], as well as spills of [[refined petroleum products]] (such as [[gasoline]], [[diesel fuel|diesel]]) and their by-products, and heavier fuels used by large [[ship]]s such as [[bunker fuel]], or the spill of any oily refuse or [[waste oil]]. Spills may take months or even years to clean up.<ref>{{cite web |url= http://vimeo.com/10216588 |title=Hindsight and Foresight, 20 Years After the Exxon Valdez Spill

⚫
'''An '''oil spill''' is an unintentional release of a [[liquid]] [[petroleum]] [[hydrocarbon]] into the environment due to human activity, and is a form of [[pollution]]. The term often refers to [[Marine (ocean)|marine]] oil spills, where oil is released into the [[ocean]] or [[coastal waters]]. Oil spills include releases of [[crude oil]] from [[Oil tanker|tankers]], [[Oil platform|offshore platforms]], [[drilling rig]]s and [[Oil well|wells]], as well as spills of [[refined petroleum products]] (such as [[gasoline]], [[diesel fuel|diesel]]) and their by-products, and heavier fuels used by large [[ship]]s such as [[bunker fuel]], or the spill of any oily refuse or [[waste oil]]. Spills may take months or even years to clean up.<ref>{{cite web |url= http://vimeo.com/10216588 |title=Hindsight and Foresight, 20 Years After the Exxon Valdez Spill
| accessdate=2010-04-30 |first=NOAA Ocean Media Center
| accessdate=2010-04-30 |first=NOAA Ocean Media Center
| date=2010-03-16 |publisher=NOAA }}</ref>
| date=2010-03-16 |publisher=NOAA }}</ref>

Revision as of 13:58, 15 June 2010

<this is a terrible site

this is a terrible site>

An oil spill is an unintentional release of a liquid petroleum hydrocarbon into the environment due to human activity, and is a form of pollution. The term often refers to marine oil spills, where oil is released into the ocean or coastal waters. Oil spills include releases of crude oil from tankers, offshore platforms, drilling rigs and wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products, and heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil. Spills may take months or even years to clean up.[1]

Oil also enters the marine environment from natural oil seeps.[2] Most human-made oil pollution comes from land-based activity, but public attention and regulation has tended to focus most sharply on seagoing oil tankers.

Environmental effects

Surf Scoter covered in oil as a result of the 2007 San Francisco Bay oil spill. Less than 1% of oil soaked birds survive, even after cleaning.[3]

The oil penetrates up the structure of the plumage of birds, reducing its insulating ability, and so making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. It also impairs birds' flight abilities to forage and escape from predators. As they attempt to preen, birds typically ingest oil that covers their feathers, causing kidney damage, altered liver function, and digestive tract irritation. This and the limited foraging ability quickly causes dehydration and metabolic imbalances. Hormonal balance alteration including changes in luteinizing protein can also result in some birds exposed to petroleum.[4] Most birds affected by an oil spill die unless there is human intervention.[5][6] Marine mammals exposed to oil spills are affected in similar ways as seabirds. Oil coats the fur of Sea otters and seals, reducing its insulation abilities and leading to body temperature fluctuations and hypothermia. Ingestion of the oil causes dehydration and impaired digestions. Because oil floats on top of water, less sunlight penetrates into the water, limiting the photosynthesis of marine plants and phytoplankton. This, as well as decreasing the fauna populations, affects the food chain in the ecosystem. There are three kinds of oil-consuming bacterial. Sulfate Reducing Bacteria (SRB) and Acid Producing Bacteria are anerobic, while General Aerobic Bacteria (GAB) are aerobic. These bacteria occur naturally and will act to remove oil from an ecosystem, and their biomass will tend to replace other populations in the food chain.

Cleanup and recovery

Clean-up efforts after the Exxon Valdez oil spill.
A US Navy oil spill response team drills with a "Harbour Buster high-speed oil containment system".

A sheen is usually dispersed (but not cleaned up) with detergents which makes oil settle to the bottom. Oils that are denser than water, such as Polychlorinated biphenyls (PCBs), can be more difficult to clean as they make the seabed toxic.[citation needed]

Recovering the oil is difficult and depends upon many factors, including the type of oil spilled, the temperature of the water (in warmer waters, some oil may evaporate), and the types of shorelines and beaches involved.[7] Methods for cleaning up include:

  • Bioremediation: use of microorganisms[8] or biological agents[9] to break down or remove oil.
  • Bioremediation Accelerator: Oleophilic, hydrophobic chemical, containing no bacteria, which chemically and physically bonds to both soluble and insoluble hydrocarbons. The bioremedation accelerator acts as a herding agent in water and on the surface, floating molecules to the surface of the water, including solubles such as phenols and BTEX, forming gel-like agglomerations. Undetectable levels of hydrocarbons can be obtained in produced water and manageable water columns. By overspraying sheen with bioremediation accelerator, sheen is eliminated within minutes. Whether applied on land or on water, the nutrient-rich emulsion creates a bloom of local, indigenous, pre-existing, hydrocarbon-consuming bacteria. Those specific bacteria break down the hydrocarbons into water and carbon dioxide, with EPA tests showing 98% of alkanes biodegraded in 28 days; and aromatics being biodegraded 200 times faster than in nature they also sometimes use the hydrofireboom to clean the oil up by taking it away from most of the oil and burning it.[10]
  • Controlled burning can effectively reduce the amount of oil in water, if done properly.[11] But it can only be done in low wind,[citation needed] and can cause air pollution.[12]
Oil slicks on Lake Maracaibo.
Volunteers cleaning up the aftermath of the Prestige oil spill.
  • Dispersants act as detergents, clustering around oil globules and allowing them to be carried away in the water.[13] This improves the surface aesthetically, and mobilizes the oil. Smaller oil droplets, scattered by currents, may cause less harm and may degrade more easily. But the dispersed oil droplets infiltrate into deeper water and can lethally contaminate coral. Recent research indicates that some dispersants are toxic to corals.[14]
  • Watch and wait: in some cases, natural attenuation of oil may be most appropriate, due to the invasive nature of facilitated methods of remediation, particularly in ecologically sensitive areas. [citation needed]
  • Dredging: for oils dispersed with detergents and other oils denser than water.
  • Skimming: Requires calm waters
  • Solidifying.[citation needed]

Equipment used includes:[11]

  • Booms: large floating barriers that round up oil and lift the oil off the water
  • Skimmers: skim the oil
  • Sorbents: large absorbents that absorb oil
  • Chemical and biological agents: helps to break down the oil
  • Vacuums: remove oil from beaches and water surface
  • Shovels and other road equipments: typically used to clean up oil on beaches

Prevention

  • Seafood Sensory Training- in an effort to detect oil in seafood, Inspectors and regulators are being trained to to sniff out seafood tainted by oil in the Gulf of Mexico and make sure the product reaching consumers is safe to eat.[15]
  • Secondary containment - methods to prevent releases of oil or hydrocarbons into environment.
  • Oil Spill Prevention Containment and Countermeasures (SPCC) program by the United States Environmental Protection Agency.
  • Double-hulling - build double hulls into vessels, which reduces the risk and severity of a spill in case of a collision or grounding. Existing single-hull vessels can also be rebuilt to have a double hull.

Environmental Sensitivity Index (ESI) mapping

Environmental Sensitivity Index (ESI) maps are used to identify sensitive shoreline resources prior to an oil spill event in order to set priorities for protection and plan cleanup strategies.[16][17] By planning spill response ahead of time, the impact on the environment can be minimized or prevented. Environmental sensitivity index maps are basically made up of information within the following three categories: shoreline type, and biological and human-use resources.[18]

Shoreline type

Shoreline type is classified by rank depending on how easy the garet would be to cleanup, how long the oil would persist, and how sensitive the shoreline is.[19] The floating oil slicks put the shoreline at particular risk when they eventually come ashore, covering the substrate with oil. The differing substrates between shoreline types vary in their response to oiling, and influence the type of cleanup that will be required to effectively decontaminate the shoreline. In 1995, the US National Oceanic and Atmospheric Administration extended ESI maps to lakes, rivers, and estuary shoreline types.[18] The exposure the shoreline has to wave energy and tides, substrate type, and slope of the shoreline are also taken into account – in addition to biological productivity and sensitivity. The productivity of the shoreline habitat is also taken into account when determining ESI ranking.[20] Mangroves and marshes tend to have higher ESI rankings due to the potentially long-lasting and damaging effects of both the oil contamination and cleanup actions. Impermeable and exposed surfaces with high wave action are ranked lower due to the reflecting waves keeping oil from coming onshore, and the speed at which natural processes will remove the oil.

Biological resources

Habitats of plants and animals that may be at risk from oil spills are referred to as “elements” and are divided by functional group. Further classification divides each element into species groups with similar life histories and behaviors relative to their vulnerability to oil spills. There are eight element groups: Birds, Reptiles and Amphibians, Fish, Invertebrates, Habitats and Plants, Wetlands, and Marine Mammals and Terrestrial Mammals. Element groups are further divided into sub-groups, for example, the ‘marine mammals’ element group is divided into dolphins, manatees, pinnipeds (seals, sea lions & walruses), polar bears, sea otters and whales.[18][20] Issues taken into consideration when ranking biological resources include the observance of a large number of individuals in a small area, whether special life stages occur ashore (nesting or molting), and whether there are species present that are threatened, endangered or rare.[21]

Human-use resources

Human use resources are divided into four major classifications; archaeological importance or cultural resource site, high-use recreational areas or shoreline access points, important protected management areas, or resource origins.[18][21] Some examples include airports, diving sites, popular beach sites, marinas, natural reserves or marine sanctuaries.

Estimating the volume of a spill

File:Bottsand.jpg
Bottsand class oil recovery ship of the German Navy.

By observing the thickness of the film of oil and its appearance on the surface of the water, it is possible to estimate the quantity of oil spilled. If the surface area of the spill is also known, the total volume of the oil can be calculated.[22]

Film thickness Quantity spread
Appearance in mm nm gal/sq mi L/ha
Barely visible 0.0000015 0.0000380 38 25 0.370
Silvery sheen 0.0000030 0.0000760 76 50 0.730
First trace of color 0.0000060 0.0001500 150 100 1.500
Bright bands of color 0.0000120 0.0003000 300 200 2.900
Colors begin to dull 0.0000400 0.0010000 1000 666 9.700
Colors are much darker 0.0000800 0.0020000 2000 1332 19.500

Oil spill model systems are used by industry and government to assist in planning and emergency decision making. Of critical importance for the skill of the oil spill model prediction is the adequate description of the wind and current fields. There is a worldwide oil spill modelling (WOSM) program.[23] Tracking the scope of an oil spill may also involve verifying that hydrocarbons collected during an ongoing spill are derived from the active spill or some other source. This can involve sophisticated analytical chemistry focused on finger printing an oil source based on the complex mixture of substances present. Largely, these will be various hydrocarbons, among the most useful being polyaromatic hydrocarbons. In addition, both oxygen and nitrogen heterocyclic hydrocarbons, such as parent and alkyl homologues of carbazole, quinoline, and pyridine, are present in many crude oils. As a result, these compounds have great potential to supplement the existing suite of hydrocarbons targets to fine tune source tracking of petroleum spills. Such analysis can also be used to follow weathering and degradation of crude spills.[24]

Largest oil spills

Main article: List of oil spills

Note: the extent of the ongoing Deepwater Horizon oil spill has not been well determined as of this writing.

Oil spills of over 100,000 tons or 30 million US gallons, ordered by tons[a]
Spill / Tanker Location Date *Tons of crude oil Barrels US Gallons Reference
Lakeview Gusher  United States, Kern County, California March 14, 1910 - September 1911 1,230,000 9,020,000 378,840,000 [25][26][27]
Gulf War oil spill  Iraq, Arabian Gulf and Kuwait January 23, 1991 750,000–1,500,000 5,500,000–11,000,000 231,000,000–462,000,000 [28][29][30]
Ixtoc I oil spill  Mexico, Gulf of Mexico June 3, 1979 – March 23, 1980 454,000–480,000 3,329,000–3,520,000 139,818,000–147,840,000 [31][32][33]
Deepwater Horizon  United States, Gulf of Mexico April 20, 2010 to present (5221 days) 136,800–701,000 1,003,200–5,140,666 42,134,400–215,908,000 [34][35]

[36]

Atlantic Empress / Aegean Captain  Trinidad and Tobago July 19, 1979 287,000 2,105,000 88,396,000 [37][38][39]
Fergana Valley  Uzbekistan March 2, 1992 285,000 2,090,000 87,780,000 [28]
Nowruz Field Platform  Iran, Arabian Gulf February 4, 1983 260,000 1,907,000 80,080,000 [40]
ABT Summer  Angola, 700 nmi (1,300 km; 810 mi) offshore May 28, 1991 260,000 1,907,000 80,080,000 [37]
Castillo de Bellver  South Africa, Saldanha Bay August 6, 1983 252,000 1,848,000 77,616,000 [37]
Amoco Cadiz  France, Brittany March 16, 1978 223,000 1,635,000 68,684,000 [28][28][37][41][42]
M/T Haven  Italy, Mediterranean Sea near Genoa April 11, 1991 144,000 1,056,000 44,352,000 [37]
Odyssey  Canada, 700 nmi (1,300 km; 810 mi) off Nova Scotia November 10, 1988 132,000 968,000 40,656,000 [37]
Sea Star  Iran, Gulf of Oman December 19, 1972 115,000 843,000 35,420,000 [28][37]
Irenes Serenade  Greece, Pylos February 23, 1980 100,000 733,000 30,800,000 [37]
Urquiola  Spain, A Coruña May 12, 1976 100,000 733,000 30,800,000 [37]
Torrey Canyon  United Kingdom, Isles of Scilly March 18, 1967 80,000–119,000 587,000–873,000 24,654,000–36,666,000 [28][37]
Exxon Valdez  United States, Alaska March 24, 1989 37,000 271,333 11,396,000

a One tonne of crude oil is roughly equal to 308 US gallons or 7.33 barrels approx.; 1 oil barrel is equal to 35 imperial or 42 US gallons.

See also

References

  1. ^ "Hindsight and Foresight, 20 Years After the Exxon Valdez Spill". NOAA. 2010-03-16. Retrieved 2010-04-30. {{cite web}}: |first= missing |last= (help)
  2. ^ http://seeps.geol.ucsb.edu/
  3. ^ "Less Than 1% of Oil-Soaked Birds Survive : TreeHugger". www.treehugger.com. Retrieved 2010-06-09.
  4. ^ C. Michael Hogan (2008), "Magellanic Penguin", GlobalTwitcher.com, ed. N. Stromberg.
  5. ^ Dunnet, G., Crisp, D., Conan, G., Bourne, W. (1982) "Oil Pollution and Seabird Populations [and Discussion]" Philosophical Transactions of the Royal Society of London. B 297(1087): 413–427
  6. ^ Untold Seabird Mortality due to Marine Oil Pollution, Elements Online Environmental Magazine.
  7. ^ Lingering Lessons of the Exxon Valdez Oil Spill
  8. ^ http://www.enviroliteracy.org/article.php/540.html
  9. ^ http://www.epa.gov/oilspill/ncp/bagents.htm
  10. ^ http://www.epa.gov/emergencies/content/ncp/products/s200.htm
  11. ^ a b "Emergency Response: Responding to Oil Spills". Office of Response and Restoration. National Oceanic and Atmospheric Administration. 2007-06-20.
  12. ^ Oil Spills
  13. ^ "Detergent and Oil Spills". NEWTON BBS. 2002-10-12. Retrieved 2007-07-29.
  14. ^ Barry, Carolyn (2007). Slick Death: Oil-spill treatment kills coral, Science News vol. 172, p. 67.
  15. ^ http://news.yahoo.com/s/ap/20100607/ap_on_bi_ge/us_gulf_oil_spill_seafood_sniffers
  16. ^ "Environmental Sensitivity Index (ESI) Maps". Retrieved 2010-05-27.
  17. ^ http://response.restoration.noaa.gov/
  18. ^ a b c d NOAA (2002). Environmental Sensitivity Index Guidelines, version 3.0. NOAA Technical Memorandum NOS OR&R 11. Seattle: Hazardous Response and Assessment Division, National Oceanic and Atmospheric Administration, 129p.
  19. ^ Gundlach, E.R. and M.O. Hayes (1978). Vulnerability of Coastal Environments to Oil Spill Impacts. Marine Technology Society. 12 (4): 18-27.
  20. ^ a b NOAA (2008). Introduction to Environmental Sensitivity Index maps. NOAA Technical Manual. Seattle: Hazardous Response and Assessment Division, National Oceanic and Atmospheric Administration, 56p.
  21. ^ a b IMO/IPIECA (1994). Sensitivity Mapping for Oil Spill Response. International Maritime Organization/ International Petroleum Industry Environmental Conservation Association Report Series, Volume 1. 22p.
  22. ^ Metcalf & Eddy. Wastewater Engineering, Treatment and Reuse. 4th ed. New York: McGraw-Hill, 2003. 98.
  23. ^ Anderson, E.L., E. Howlett, K. Jayko, V. Kolluru, M. Reed, and M. Spaulding. 1993. The worldwide oil spill model (WOSM): an overview. Pp. 627–646 in Proceedings of the 16th Arctic and Marine Oil Spill Program, Technical Seminar. Ottawa, Ontario: Environment Canada.
  24. ^ Wang, Z., M. Fingas, and D.S. Page. 1999. Oil spill identification. Journal of Chromatography A. 843: 369-411. doi:10.1016/S0021-9673(99)00120-X.
  25. ^ Rintoul, William, Drilling Through Time, pp. 13-15, (Sacramento, California: California Department of Conservation, Division of Oil and Gas, 1990).
  26. ^ Lakeview Gusher of 1910, Maricopa, California
  27. ^ Lakeview Gusher Site
  28. ^ a b c d e f "Oil Spill History". The Mariner Group. Retrieved 2008-11-02.
  29. ^ "Gulf Found to Recover from War's Oil Spill, The New York Times (March 17, 1993). Retrieved 2010-6-7.
  30. ^ "Major Oil Spills". Retrieved 2008-11-02.
  31. ^ "IXTOC I". National Oceanic and Atmospheric Administration. Retrieved 2008-11-03.
  32. ^ "Ixtoc 1 oil spill: flaking of surface mousse in the Gulf of Mexico". Nature Publishing Group. Retrieved 2008-11-03.
  33. ^ John S. Patton, Mark W. Rigler, Paul D. Boehm & David L. Fiest (1981-03-19). "Ixtoc 1 oil spill: flaking of surface mousse in the Gulf of Mexico". NPG (Nature Publishing Group). Retrieved 2007-07-29.{{cite web}}: CS1 maint: multiple names: authors list (link)
  34. ^ Ian R. MacDonald (21 May 2010). "The Measure of a Disaster". The New York Times. Retrieved 7 June 2010. {{cite news}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  35. ^ "Flow Rate Group Provides Preliminary Best Estimate Of Oil Flowing from BP Oil Well". Deepwater Horizon Unified Response Command. 27 May 2010. Retrieved 7 June 2010.
  36. ^ "Admiral Allen; Dr. McNutt Provide Updates on Progress of Scientific Teams Analyzing Flow Rates from BP's Well". 2010-06-10.
  37. ^ a b c d e f g h i j "Major Oil Spills". International Tanker Owners Pollution Federation. Retrieved 2008-11-02.
  38. ^ "Atlantic Empress". Centre de Documentation de Recherche et d'Expérimentations. Retrieved 2008-11-10.
  39. ^ "Tanker Incidents". Retrieved 2009-07-19.
  40. ^ "Oil Spills and Disasters". Retrieved 2008-11-16.
  41. ^ "Amoco Cadiz". National Oceanic and Atmospheric Administration. Retrieved 2008-11-16.
  42. ^ [1]

Further reading

  • The World Almanac and Book of Facts, 2004
  • Oil Spill Case Histories 1967-1991, NOAA/Hazardous Materials and Response Division, Seattle WA, 1992
  • Nelson-Smith, Oil Pollution and Marine Ecology, Elek Scientific, London, 1972; Plenum, New York, 1973
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