Accession Number : AD0714260

Title :   Oceanographic Observations of Oil Slicks During the Chevron Spill, March, 1970.

Descriptive Note : Technical rept.,

Corporate Author : LOUISIANA STATE UNIV BATON ROUGE COASTAL STUDIES INST

Personal Author(s) : Murray,Stephen P. ; Smith,William G. ; Sonu,Choule J.

Report Date : 30 SEP 1970

Pagination or Media Count : 115

Abstract : Oceanographic observations near the Chevron spilling well off the Mississippi Delta in March, 1970, revealed relative roles of various physical factors of the regional estuarine system in the behavior of oil slicks. Surface stress from the wind was most important; at speeds above 15 mph the slick orientation was generally determined by the wind direction. The wind also indirectly affected oil which was sunk by dispersant in that wind waves promoted mixing, which in turn affected the vertical stability, hence eventually the velocity profile. Wind setups and setdowns were correlated with downward and upward isopycnal movements, respectively. Both calculations and observations showed that tidal currents produced an L-shaped slick geometry when winds were below about 15 mph. The diurnal rotation of the tidal currents served to limit the excursion length of oil from the source, keeping it short of the nearest shore. The presence of fresh water from the Mississippi River in the surface layer and the consequent development of convergence lines often formed a natural barrier, preventing oil from encroaching upon the shore. Theoretical analysis using turbulent diffusion theory disclosed that the area and length of a steady-state oil slick increased with oil discharge but decreased with current speed and the lateral diffusion coefficient. (Author)

Descriptors :   (*WATER POLLUTION, *OILS), (*ESTUARIES, WATER POLLUTION), (*MEXICO GULF, WATER POLLUTION), WIND, WATER WAVES, INTERACTIONS, TIDES, COASTAL REGIONS, TEMPERATURE, SALINITY, DELTAS, DENSITY, PREDICTIONS, DATA PROCESSING, DIFFUSION, STATISTICAL DATA, PETROLEUM PRODUCTS, MISSISSIPPI, PETROLEUM INDUSTRY

Subject Categories : Hydrology, Limnology and Potamology
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE