MATERIAL_TYPE: weathered oil
MATERIAL: Weathered oil from the Deepwater Horizon spill
COLLECTION_LOCALITY:Gulf of Mexico
COLLECTION_LATITUDE: 28deg 53' 57.0" N
COLLECTION_LONGITUDE: 89deg 05' 50.7" W
ORIGINAL_DONOR: Gregg Swayze , USGS
CURRENT_SAMPLE_LOCATION: USGS, Denver
Sample is an emulsified oil collected from the Gulf of Mexico soon after the start of the Deepwater Horizon (Macondo-252, BP 2010) oil spill in 2010. The original sample had a 60:40 oil to water ratio. This sample was then separated into oil and water using a heat lamp and recombined into oil water emulsions of different percentages. The water used was oil free water from the Gulf of Mexico collecte the same day.
This series contains a synthetic emulsion with oil to water ratio of 92:8 using oil heat separated from DWH10-3.
No additional compositional details available.
SPECTROSCOPIC_DISCUSSION: Spectra of five thicknesses of the emulsion were measured: 0.05 0.1, 0.5, 1.85, and 4 mm. The spectra show C-H absorptions at 1.2, 1.7 and 2.25 microns. Note that the high-oil-content spectra vary in color, at visible wavelengths, with thickness while the color of higher water content oil emulsions change little in color with thickness. The reflectance level and oil:water ratio can vary by up to plus or minus a few percent from its reported value given uncertainties in the oil:water ratio of the prepared sample, its water droplet size, and the optical configuruation used to measure it.
This spectrum was published and described in:
Clark, R.N., Swayze, G.A., Leifer, I. Livo, K.E., Kokaly, R., Hoefen, T., Lundeen, S., Eastwood, M., Green, R.O., Pearson, N., Sarture, C., McCubbin, I., Roberts, D., Bradley, E., Steele, D., Ryan, T., Dominguez, R., and the Air borne Visible/Infrared Imaging Spectrometer (AVIRIS) Team, 2010, A method for quantitative mapping of thick oil spills using imaging spectroscopy: U.S. Geological Survey Open-File Report 2010-1167, 51 p.
SPECTRAL_PURITY: 1a2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns