Jump to content

Oil spill: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
Line 8: Line 8:
==Largest oil spills==
==Largest oil spills==
{{Main|List of oil spills}}
{{Main|List of oil spills}}
Crude oil and refined fuel spills from [[tanker (ship)|tanker ship]] accidents have damaged natural [[ecosystem]]s in [[Alaska]], the [[Gulf of Mexico]], the [[Galapagos Islands]], France and many [[List of oil spills|other places]]. The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons (e.g., [[Bp oil spill|Deepwater Horizon Oil Spill]], [[Atlantic Empress]], [[Amoco Cadiz]]). Smaller spills have already proven to have a great impact on ecosystems, such as the [[Exxon Valdez oil spill]].

Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin [[oil slick]] which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly [[bulldozed]] around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.

{| class="wikitable sortable" style="text-align:left"
{| class="wikitable sortable" style="text-align:left"
|+ '''Largest oil spills, ordered by [[ton]]s''' {{ref label|Note|a|a}}
|+ '''Largest oil spills, ordered by [[ton]]s''' {{ref label|Note|a|a}}

Revision as of 06:03, 18 August 2012

Kelp after an oil spill
Oil Sick from the Montara oil spill in the Timor Sea, September, 2009

An oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution. The term is usually applied to marine oil spills, where oil is released into the ocean or coastal waters, but spills may also occur on land. Oil spills may be due to 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, heavier fuels used by large ships such as bunker fuel, or the spill of any oily refuse or waste oil.

Major oil spills include the Kuwaiti oil fires, Kuwaiti oil lakes, Lakeview Gusher, Gulf War oil spill, and the Deepwater Horizon oil spill. Spilt oil penetrates into the structure of the plumage of birds and the fur of mammals, reducing its insulating ability, and making them more vulnerable to temperature fluctuations and much less buoyant in the water. Cleanup and recovery from an oil spill is difficult and depends upon many factors, including the type of oil spilled, the temperature of the water (affecting evaporation and biodegradation), and the types of shorelines and beaches involved.[1] Spills may take weeks, months or even years to clean up.[2]

Largest oil spills

Main article: List of oil spills

Crude oil and refined fuel spills from tanker ship accidents have damaged natural ecosystems in Alaska, the Gulf of Mexico, the Galapagos Islands, France and many other places. The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons (e.g., Deepwater Horizon Oil Spill, Atlantic Empress, Amoco Cadiz). Smaller spills have already proven to have a great impact on ecosystems, such as the Exxon Valdez oil spill.

Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin oil slick which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly bulldozed around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.

Largest oil spills, ordered by tons [a]
Spill / Tanker Location Date *Tons of crude oil
(thousands)		 Barrels
(thousands)		 US Gallons
(thousands)		 References
Kuwaiti oil fires [b]  Kuwait January 1991 - November 1991 136,000-205,000 1,000,000-1,500,000 42,000,000-63,000,000 [3]
Kuwaiti oil lakes [c]  Kuwait January 1991 - November 1991 3,409-6,818 25,000-50,000 1,050,000-2,100,000 [4][5][6]
Lakeview Gusher  United States, Kern County, California March 14, 1910 – September 1911 1,200 9,000 378,000 [7]
Gulf War oil spill [d]  Kuwait, Iraq, and the Persian Gulf January 19, 1991 - January 28, 1991 818–1,091 6,000–8,000 252,000–336,000 [4][8][9]
Deepwater Horizon  United States, Gulf of Mexico April 20, 2010 – July 15, 2010 560-585 4,100-4,900 172,000-180,800 [10][11][12][13][14]
Ixtoc I  Mexico, Gulf of Mexico June 3, 1979 – March 23, 1980 454–480 3,329–3,520 139,818–147,840 [15][16][17]
Atlantic Empress / Aegean Captain  Trinidad and Tobago July 19, 1979 287 2,105 88,396 [18][19][20]
Fergana Valley  Uzbekistan March 2, 1992 285 2,090 87,780 [21]
Nowruz Field Platform  Iran, Persian Gulf February 4, 1983 260 1,907 80,080 [22]
ABT Summer  Angola, 700 nmi (1,300 km; 810 mi) offshore May 28, 1991 260 1,907 80,080 [18]
Castillo de Bellver South Africa South Africa, Saldanha Bay August 6, 1983 252 1,848 77,616 [18]
Amoco Cadiz  France, Brittany March 16, 1978 223 1,635 68,684 [18][21][21][23][24]

Environmental effects

Surf Scoter covered in oil as a result of the 2007 San Francisco Bay oil spill.

Oil penetrates into the structure of the plumage of birds and the fur of mammals, reducing its insulating ability, and making them more vulnerable to temperature fluctuations and much less buoyant in the water.

Animals that rely on scent to find their babies or mothers fade away due to the strong scent of the oil. This causes a baby to be rejected and abandoned, leaving the babies to starve and eventually die. Oil can impair a bird's ability to fly, preventing it from foraging or escaping from predators. As they preen, birds may ingest the oil coating their feathers, irritating the digestive tract, altering liver function, and causing kidney damage. Together with their diminished foraging capacity, this can rapidly result in dehydration and metabolic imbalance. Some birds exposed to petroleum also experience changes in their hormonal balance, including changes in their luteinizing protein.[25] The majority of birds affected by oil spills die without human intervention.[26][27] Some studies have suggested that less than one percent of oil-soaked birds survive, even after cleaning,[28] although the survival rate can also exceed ninety percent, as in the case of the Treasure oil spill.[29]

Heavily furred marine mammals exposed to oil spills are affected in similar ways. Oil coats the fur of sea otters and seals, reducing its insulating effect, and leading to fluctuations in body temperature and hypothermia. Oil can also blind an animal, leaving it defenseless. The ingestion of oil causes dehydration and impairs the digestive process. Animals can be poisoned, and may die from oil entering the lungs or liver.

There are three kinds of oil-consuming bacteria. Sulfate-reducing bacteria (SRB) and acid-producing bacteria are anaerobic, 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

A U.S. Air Force Reserve plane sprays Corexit dispersant over the Deepwater Horizon oil spill in the Gulf of Mexico.
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".

Cleanup and recovery from an oil spill is difficult and depends upon many factors, including the type of oil spilled, the temperature of the water (affecting evaporation and biodegradation), and the types of shorelines and beaches involved.[30]

Methods for cleaning up include:[31]

  • Bioremediation: use of microorganisms[32] or biological agents[33] 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 bioremediation 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.[34]
  • Controlled burning can effectively reduce the amount of oil in water, if done properly.[35] But it can only be done in low wind,[citation needed] and can cause air pollution.[36]
Oil slicks on Lake Maracaibo.
Volunteers cleaning up the aftermath of the Prestige oil spill.
  • Dispersants can be used to dissipate oil slicks.[37] A dispersant is either a non-surface active polymer or a surface-active substance added to a suspension, usually a colloid, to improve the separation of particles and to prevent settling or clumping. They may rapidly disperse large amounts of certain oil types from the sea surface by transferring it into the water column. They will cause the oil slick to break up and form water-soluble micelles that are rapidly diluted. The oil is then effectively spread throughout a larger volume of water than the surface from where the oil was dispersed. They can also delay the formation of persistent oil-in-water emulsions. However, laboratory experiments showed that dispersants increased toxic hydrocarbon levels in fish by a factor of up to 100 and may kill fish eggs.[38] Dispersed oil droplets infiltrate into deeper water and can lethally contaminate coral. Recent research indicates that some dispersants are toxic to corals.[39]
  • 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 such as wetlands.[40]
  • Dredging: for oils dispersed with detergents and other oils denser than water.
  • Skimming: Requires calm waters
  • Solidifying: Solidifiers are composed of dry hydrophobic polymers that both adsorb and absorb. They clean up oil spills by changing the physical state of spilled oil from liquid to a semi-solid or a rubber-like material that floats on water. Solidifiers are insoluble in water, therefore the removal of the solidified oil is easy and the oil will not leach out. Solidifiers have been proven to be relatively non-toxic to aquatic and wild life and have been proven to suppress harmful vapors commonly associated with hydrocarbons such as Benzene, Xylene, Methyl Ethyl, Acetone and Naphtha. The reaction time for solidification of oil is controlled by the surf area or size of the polymer as well as the viscosity of the oil. Some solidifier product manufactures claim the solidified oil can be disposed of in landfills, recycled as an additive in asphalt or rubber products, or burned as a low ash fuel. A solidifier called C.I.Agent (manufactured by C.I.Agent Solutions of Louisville, Kentucky) is being used by BP in granular form as well as in Marine and Sheen Booms on Dauphin Island, AL and Fort Morgan, MS to aid in the Deepwater Horizon oil spill cleanup.
  • Vacuum and centrifuge: oil can be sucked up along with the water, and then a centrifuge can be used to separate the oil from the water - allowing a tanker to be filled with near pure oil. Usually, the water is returned to the sea, making the process more efficient, but allowing small amounts of oil to go back as well. This issue has hampered the use of centrifuges due to a United States regulation limiting the amount of oil in water returned to the sea.[41]

Equipment used includes:[35]

  • 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

Further information: Offshore oil spill prevention and response
  • 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.[42][43] 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.[44]

Shoreline type

Shoreline type is classified by rank depending on how easy the garet would be to clean up, how long the oil would persist, and how sensitive the shoreline is.[45] 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.[44] 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.[46] 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, 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.[44][46] Problems 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.[47]

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.[44][47] Some examples include airports, diving sites, popular beach sites, marinas, natural reserves or marine sanctuaries.

Estimating the volume of a spill

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.[48]

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 0.00004 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.[49] 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.[50]

See also

References

  1. ^ Lingering Lessons of the Exxon Valdez Oil Spill
  2. ^ "Hindsight and Foresight, 20 Years After the Exxon Valdez Spill". NOAA. 2010-03-16. Retrieved 2010-04-30. {{cite web}}: |first= missing |last= (help)
  3. ^ CNN.com, Kuwait still recovering from Gulf War fires, 3 Jan. 2003.
  4. ^ a b United Nations, Updated Scientific Report on the Environmental Effects of the Conflict between Iraq and Kuwait, 8 Mar. 1993.
  5. ^ United States Geological Survey, Campbell, Robert Wellman, ed. 1999. Iraq and Kuwait: 1972, 1990, 1991, 1997. Earthshots: Satellite Images of Environmental Change. U.S. Geological Survey. http://earthshots.usgs.gov, revised 14 Feb. 1999.
  6. ^ National Aeronautics and Space Administration, Goddard Space Flight Center News, 1991 Kuwait Oil Fires, 21 Mar. 2003.
  7. ^ Harvey, Steve (2010-06-13). "California's legendary oil spill". Los Angeles Times. Retrieved 2010-07-14.
  8. ^ United States Environmental Protection Agency, Report To Congress United States Gulf Environmental Technical Assistance From January 27 - July 31 1991
  9. ^ National Oceanic and Atmospheric Administration, Office of Response and Restoration, Emergency Response Division, Incident News: Arabian Gulf Spills, updated 18 May 2010.
  10. ^ Campbell Robertson /Clifford Krauss (2 August 2010). "Gulf Spill Is the Largest of Its Kind, Scientists Say". The New York Times. New York Times. Retrieved 2 August 2010.
  11. ^ CNN (1 July 2010). "Oil disaster by the numbers". CNN. Retrieved 1 July 2010. {{cite news}}: |author= has generic name (help)
  12. ^ Consumer Energy Report (20 June 2010). "Internal Documents: BP Estimates Oil Spill Rate up to 100,000 Barrels Per Day". Consumer Energy Report. Retrieved 20 June 2010.
  13. ^ Big Oil Plans Rapid Response to Future Spills
  14. ^ Khatchadourian, Raffi (March 14, 2011). "The Gulf War". The New Yorker. {{cite web}}: Italic or bold markup not allowed in: |publisher= (help)
  15. ^ "IXTOC I". National Oceanic and Atmospheric Administration. Retrieved 2008-11-03.
  16. ^ "Ixtoc 1 oil spill: flaking of surface mousse in the Gulf of Mexico". Nature Publishing Group. Retrieved 2008-11-03.
  17. ^ 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)
  18. ^ a b c d "Major Oil Spills". International Tanker Owners Pollution Federation. Retrieved 2008-11-02.
  19. ^ "Atlantic Empress". Centre de Documentation de Recherche et d'Expérimentations. Retrieved 2008-11-10.
  20. ^ "Tanker Incidents". Retrieved 2009-07-19.
  21. ^ a b c "Oil Spill History". The Mariner Group. Retrieved 2008-11-02.
  22. ^ "Oil Spills and Disasters". Retrieved 2008-11-16.
  23. ^ "Amoco Cadiz". National Oceanic and Atmospheric Administration. Retrieved 2008-11-16.
  24. ^ [1][dead link]
  25. ^ C. Michael Hogan (2008), "Magellanic Penguin", It can take over 1 year to solve the problem of an oil spill. GlobalTwitcher.com, ed. N. Stromberg.
  26. ^ 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
  27. ^ Untold Seabird Mortality due to Marine Oil Pollution, Elements Online Environmental Magazine.
  28. ^ "Expert Recommends Killing Oil-Soaked Birds". Spiegel Online. May 6, 2010. Retrieved August 1, 2011.
  29. ^ AC Wolfaardt, AJ Williams, LG Underhill, RJM Crawford & PA Whittington (2009): Review of the rescue, rehabilitation and restoration of oiled seabirds in South Africa, especially African penguins Spheniscus demersus and Cape gannets Morus capensis, 1983–2005, African Journal of Marine Science, 31:1, 31-54
  30. ^ Lingering Lessons of the Exxon Valdez Oil Spill
  31. ^ Oil spill cleanup technology Patents and patent applications
  32. ^ "The Environmental Literacy Council - Oil Spills". Enviroliteracy.org. 2008-06-25. Retrieved 2010-06-16.
  33. ^ "Biological Agents". {{cite web}}: Text "Emergency Management" ignored (help); Text "US EPA" ignored (help)
  34. ^ "S-200 | NCP Product Schedule | Emergency Management | US EPA". Epa.gov. Retrieved 2010-06-16.
  35. ^ a b "Emergency Response: Responding to Oil Spills". Office of Response and Restoration. National Oceanic and Atmospheric Administration. 2007-06-20.
  36. ^ Oil Spills
  37. ^ "Spill Response - Dispersants". International Tanker Operators Pollution Federation Limited. Retrieved 2010-05-03.
  38. ^ "Spill Response - Dispersants Kill Fish Eggs". journal Environmental Toxicology and Chemistry. Retrieved 2010-05-21.
  39. ^ Barry, Carolyn (2007). Slick Death: Oil-spill treatment kills coral, Science News vol. 172, p. 67.
  40. ^ Pezeshki, S. R., Hester, M. W., Lin, Q. & Nyman, J. A. (2000). The effects of oil spill clean-up on dominant US Gulf coast marsh macrophytes: a review. Environmental Pollution. 108: 129-139.
  41. ^ Fountain, Henry (2010-06-24). "Advances in Oil Spill Cleanup Lag Since Valdez". New York Times. Retrieved 2010-07-05.
  42. ^ "Environmental Sensitivity Index (ESI) Maps". Retrieved 2010-05-27.
  43. ^ "NOAA's Ocean Service Office of Response and Restoration". Response.restoration.noaa.gov. Retrieved 2010-06-16.
  44. ^ 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.
  45. ^ Gundlach, E.R. and M.O. Hayes (1978). Vulnerability of Coastal Environments to Oil Spill Impacts. Marine Technology Society. 12 (4): 18-27.
  46. ^ 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.
  47. ^ 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.
  48. ^ Metcalf & Eddy. Wastewater Engineering, Treatment and Reuse. 4th ed. New York: McGraw-Hill, 2003. 98.
  49. ^ 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.
  50. ^ 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.

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


—

Retrieved from "https://en.wikipedia.org/w/index.php?title=Oil_spill&oldid=507945275"