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Distribution of hydrocarbons released during the 2010 MC252 oil spill in deep offshore waters
2013
Spier, Chelsea | Stringfellow, William T. | Hazen, Terry C. | Conrad, Mark
The explosion of the Deepwater Horizon oil platform on April 20th, 2010 resulted in the second largest oil spill in history. The distribution and chemical composition of hydrocarbons within a 45 km radius of the blowout was investigated. All available certified hydrocarbon data were acquired from NOAA and BP. The distribution of hydrocarbons was found to be dispersed over a wider area in subsurface waters than previously predicted or reported. A deepwater hydrocarbon plume predicted by models was verified and additional plumes were identified. Because the samples were not collected systematically, there is still some question about the presence and persistence of an 865 m depth plume predicted by models. Water soluble compounds were extracted from the rising oil in deepwater, and were found at potentially toxic levels outside of areas previously reported to contain hydrocarbons. Application of subsurface dispersants was found to increase hydrocarbon concentration in subsurface waters.
Mostrar más [+] Menos [-]Effects of seasonal variations on sediment-plume streaks from dredging operations
2018
Kim, Nam Hoon | Pham, Van Sy | Hwang, Jin Hwan | Won, Nam Il | Ha, Ho Kyung | Im, Jungho | Kim, Youngsung
When mixtures of aggregates and water dredged from the seabed are discharged at the surface into the adjacent water from a barge, coarse sediments sink immediately and fine sediments are suspended forming a plume. Recently, elongated plumes of fine sediment were observed by satellites near a dredging location on the continental shelf. Such plume streaks were longer in certain conditions with seasonality than expected or reported previously. Therefore, the present work studied the appearance of sediment plume with field measurements and numerical simulations and explains the seasonally varying restoring force and thicknesses of the surface mixed layer resulting from the vertical density distribution near the surface, along with mixing by hydrodynamic process. The resulting mixtures, after vertical restoring and mixing with the surroundings, determine the horizontal transport of suspended sediments. A numerical model successfully reproduced and explained the results from field measurements and satellite images along with the seasonal variations.
Mostrar más [+] Menos [-]A review of the physical impacts of sediment dispersion from aggregate dredging
2015
Spearman, Jeremy
The disturbance and subsequent dispersion of sediment arising from aggregate dredging results in increases in suspended sediment concentrations and, potentially, settlement of fine sediment or sand onto the bed, which may both cause adverse effects on local ecology. This subject is one area which has seen much research over many years and this paper sets out to synthesise some basic general conclusions for use when assessing the significance of planned operations. The literature detailing the dispersion of fine sediment plumes, and the longer term dispersion of sand released through the dredging process, is scrutinised, and in some cases re-evaluated, and used to identify an evidence-based footprint of potential impact.
Mostrar más [+] Menos [-]Behavior and dynamics of bubble breakup in gas pipeline leaks and accidental subsea oil well blowouts
2018
Wang, Binbin | Socolofsky, Scott A. | Lai, Chris C.K. | Adams, E Eric | Boufadel, Michel C.
Subsea oil well blowouts and pipeline leaks release oil and gas to the environment through vigorous jets. Predicting the breakup of the released fluids in oil droplets and gas bubbles is critical to predict the fate of petroleum compounds in the marine water column. To predict the gas bubble size in oil well blowouts and pipeline leaks, we observed and quantified the flow behavior and breakup process of gas for a wide range of orifice diameters and flow rates. Flow behavior at the orifice transitions from pulsing flow to continuous discharge as the jet crosses the sonic point. Breakup dynamics transition from laminar to turbulent at a critical value of the Weber number. Very strong pure gas jets and most gas/liquid co-flowing jets exhibit atomization breakup. Bubble sizes in the atomization regime scale with the jet-to-plume transition length scale and follow −3/5 power-law scaling for a mixture Weber number.
Mostrar más [+] Menos [-]Mercury levels in the plumage of red-billed gulls Larus novaehollandiae scopulinus of known sex and age
1990
Furness, R.W. | Lewis, S.A. | Mills, J.A.
An association of mangrove mutation, scarlet ibis, and mercury contamination in Trinidad, West Indies
1999
Klekowski, E.J. | Temple, S.A. | Siung-Chang, A.M. | Kumarsingh, K. (Biology Department, University of Massachusetts, Amherst, MA 01003 (USA))
Deposition rates of heavy metals in south-eastern Schleswig-Holstein (Germany) and their temporal and spacial trends as investigated by means of moulted goshawk feathers
1992
Ellenberg, H. (Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Weltforstwirtschaft) | Kuehnast, O.
Cleansing oiled feathers - magnetically
1999
Orbell, J.D. | Tan, E.K. | Coutts, M. | Bigger, S.W. | Ngeh, L.N. (School of Life Sciences and Technology, Victoria University of Technology, P.O. Box 14428, Melbourne City MC, Victoria 8001 (Australia))