AL -8 (m/z 217)

MS-44 (m/z 217)

S R

aaa 27

R

baD

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S R

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Macondo-1 (m/z 217)

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R S

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ab

ab 34

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23T

C24

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Ts

ab 29

ab 30

ab 31

ab 32

33

ab

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R S

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R R

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ab

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23T

C24

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Ts

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ab 30

ab 31

ab 32

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ab

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ab 30

ab 31

ab 32

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R S

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Macondo-1 (m/z 191)

AL -8 (m/z 191)

MS-44 (m/z 191)

29D

29D

29D

Time Time

Response Response Response

A

E F

C D

B

Ts/TmC27DS/C29S24tri/23tri29D/29Htriplet26tri/25tri28tri/29triC28R/C28S20tri/23triC29/C3035S/34S22tri/21triC31S/C30

G1

G4

G2

G3

Heirarchical cluster diagram of 39 sediment 

samples, 1 tarball, and the M-1 well oil from the 

northern Gulf of Mexico coast. The clusters marked 

in red, orange, and green indicates sediments with 

similar distribution of petroleum biomarkers. The 

cluster of blue crosses contains the sediment and 

tarball from site FL-18 and the M-1 well oil.

Figure 3. Hierarchical cluster diagram of 59 

sediment samples, 7 M-1 well oil splits, and 

20 tarballs from the northern Gulf of 

Mexico coast. The cluster marked in red indicates sediments and tarballs that group 

with M-1 well oil. The cluster of blue Xs 

represents a likely mixture of oils, possibly 

but not veriably including M-1 well oil. 

The colored squares are a two-way cluster 

representing the range in values of each 

variable, dark red being highest, dark blue 

lowest, and intermediate shades color 

being intermediate values.

Macondo–1 Well Oil in Sediment and Tarballs from the Northern Gulf of Mexico Shoreline 

By Florence L. Wong, Robert J. Rosenbauer, Pamela L. Campbell, Angela Lam, Thomas D. Lorenson, Frances D. Hostettler, and Burt Thomas

U.S. Geological Survey, Pacific Coastal and Marine Science Center, Menlo Park, California (contact: fwong@usgs.gov)

U.S. Department of the Interior

U.S. Geological Survey

2011

Open–File Report 2011–1164

Summary

 From April 20 through July 15, 2010, an estimated 4.4 million barrels 

(1 barrel = 42 gallons [~700,000 cu m]) of crude oil spilled into the 

northern Gulf of Mexico (nGOM) from the ruptured British Petroleum 

(BP) Macondo–1 (M–1) well after the explosion of the drilling platform 

Deepwater Horizon (Crone and Tolstoy, 2010). In addition, ~1.84 million 

gallons (~7,000 cu m) of hydrocarbon-based Corexit dispersants were 

applied to the oil both on and below the sea surface (Operational Science 

Advisory Team, 2010). An estimate of the total extent of the surface oil 

slick, derived from wind, ocean currents, aerial photography, and satellite 

imagery, was 68,000 square miles (~180,000 sq km; Amos and Norse, 

2010). Spilled oil from this event impacted sensitive habitat along the 

shores of the nGOM.

 In response to this environmental catastrophe, the U.S. Geological 

Survey (USGS) collected coastal sediment and tarball samples along the 

shores of the nGOM from Texas to Florida before and after oil made 

landfall. These sites included priority areas of the nGOM at highest risk 

for oil contamination. These areas included coastal wetlands, shorelines, 

and barrier islands that could suffer severe environmental damage if a 

significant amount of oil came ashore.

 Samples were collected before oil reached land from 69 sites; 49 were 

revisited to collect samples after oil landfall. This poster focuses on the 

samples from locations that were sampled on both occasions. The USGS 

samples and one M–1 well-oil sample provided by BP were analyzed for 

a suite of diagnostic geochemical biomarkers. Aided by multivariate 

statistical analysis, the M–1 well oil was not detected in the samples 

collected before landfall but have been identified in sediment and tarballs 

collected from Louisiana, Alabama, Mississippi, and Florida after 

landfall. None of the sediment hydrocarbon extracts from Texas 

correlated with the M–1 well oil. Oil-impacted sediment is confined to the 

shoreline adjacent to the cumulative oil slick of the Deepwater Horizon 

oil spill and no impact was observed outside of this area (Rosenbauer and 

others, 2010, 2011). Incorporation of the analytical data in geographical 

information systems (GIS) offers querying capabilities and visualizations 

such as those demonstrated here.

Acknowledgments

 Reviews by Mary McGann and Peter Swarzenksi greatly improved this presentation.

References Cited

Amos, John, and Norse, Elliott, 2010, BP spill was a greater disaster than public knew: news 

release by SkyTruth and ACBI, accessed November 10, 2010 at

http://mcbi.org/news/PRNorse–Amos–2010.pdf.

Crone, T.J., and Tolstoy, M., 2010, Magnitude of the 2010 Gulf of Mexico oil leak: Science, v. 

330, p. 634.

National Oceanic and Atmospheric Administration, 2010, Cumulative trajectory map, April 30: 

accessed January 5, 2011, at http://response.restoration.noaa.gov/book_shelf/1891_TM–2010– 

04–30–1453.pdf.

Operational Science Advisory Team (OSAT), 2010, Summary report for sub-sea and sub-surface 

oil and dispersant detection—sampling and monitoring; prepared for Paul F. Zukunft, RADM, 

U.S. Coast Guard, Federal On–Scene Coordinator, Deepwater Horizon MC252, accessed June 

23, 2011, at 

http://www.restorethegulf.gov/sites/default/files/documents/pdf/OSAT_Report_FINAL_17DEC.

pdf

Rosenbauer, R.J., Campbell, P.L., Lam, Angela, Lorenson, T.D., Hostettler, F.D., Thomas, Burt, 

and Wong, F.L., 2010, Reconnaissance of Macondo–1 well oil in sediment and tarballs from the 

northern Gulf of Mexico shoreline, Texas to Florida: U.S. Geological Survey Open–File Report 

2010–1290, 22 p. (available at http://pubs.usgs.gov/of/2010/1290/).

Rosenbauer, R.J., Campbell, P.L., Lam, Angela, Lorenson, T.D., Hostettler, F.D., Thomas, Burt, 

and Wong, F.L., 2011, Petroleum hydrocarbons in sediment from the northern Gulf of Mexico 

shoreline, Texas to Florida: U.S. Geological Survey Open–File Report 2011–1014, 22 p. 

(available at http://pubs.usgs.gov/of/2011/1014/).

Figure 6. Photograph of oil from the Deepwater Horizon oil spill 

floating on the surface of the water in Bay Jimmy in Plaquemines 

Parish, Louisiana, June 2010. Booms were emplaced in an attempt to 

keep the oil out of the marshes. See figure 5 for photo location. (AP 

Photo, Gerald Herbert, http://www.cbsnews.com/stories/2010/06/

29/tech/main6629462.shtml)

GIS tools organize and visualize critical analytical data.

Figure 1. Map showing locations of shoreline sediment samples 

that were collected both before (May 2010) and after (October 

2010) local landfall of BP oil. Biomarker analysis of samples 

collected before landfall: green squares, detectable oil, shows that 

none of these samples was related to BP Macondo–1 oil; white 

squares, oil was not detected; two samples had too few biomarkers 

to provide identification; and one sample bottle (not analyzed) was 

broken in transit. The blue shading depicts the cumulative areal 

coverage of the BP M–1 well-oil spill as of April 30, 2010 

(National Oceanic and Atmospheric Administration, 2010).

Figure 2. Map indicating the approximate geochemical 

composition of the extracted organic matter of samples collected 

after M–1 oil made landfall across the Gulf of Mexico. The gulf is 

affected by a significant quantity and variety of natural oil seepage. 

As a result, both thermally immature and mature oil residues, 

likely from natural seepage, can be detected in some samples.

 A blue pie marker indicates sediment containing oil that 

correlates with M–1 well oil; a white marker indicates sediment 

containing mature oil that does not correlate with M–1 well oil; a 

purple marker indicates sediment containing immature oil and (or) 

biogenic material that does not correlate with M–1 well oil; and an 

orange marker indicates terrigenous material. Pie markers with a 

combination of colors are not intended to indicate proportion but 

rather to indicate that the sediment contains a mixture of 

components. The pie diagrams are offset from the sample locations 

for clarity. See figure 1 for sample locations. 

Figure 3. Map showing location of sediment samples collected 

after oil landfall that correlate with M–1 well oil. Correlated M–1 

oil is indicated with a blue-filled circle; uncorrelated oil with an 

open circle; and a likely mixture of oils (possibly but not verifiably 

including M–1 well oil) with a half-filled circle. 

Figure 4. Map showing locations of tarball samples collected in 

October 2010 after oil landfall that correlate with M–1 well oil. 

Correlated M–1 tarballs are indicated with a blue-filled diamond; 

uncorrelated tarballs with an open diamond.

Figure 8. Photograph showing tarball found on the beach on 

Dauphin Island, Alabama, in May 2010. See figure 5 for photo 

location. (Photo from NOAA, http://oceanservice.noaa.gov/

deepwaterhorizon/images/dauphinisland3_b.jpg)

10 cm

Figure 7. Photograph of oil stranded on the north Chandeleur 

Islands on May 8, 2010. Four areas with this kind of oiling were 

100–300 m (300–900 ft) long by 0.5–2 m (1.5–6 ft) wide, with 

25–90 percent distribution of oil <1 cm (0.5 in) thick. Three of the 

four areas were on the north sides of the inlets between the islands. 

See figure 5 for photo location. (Photo from NOAA, 

http://www.noaa.gov/deepwaterhorizon/video/oceanservice/deepw

aterhorizon/images/chandeleur_island_b.jpg)

Figure 5. Map showing locations of photographs (figs. 6–8). The 

blue shading depicts the extent of BP oil as of mid-July 2010 

(Amos and Norse, 2010).

Plaquemines

Parish

Dauphin

Island

Chandeleur

Islands

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not

imply endorsement by the U.S. Government

Digital files available at http://pubs.usgs.gov/of/2011/1164/

Suggested Citation: Wong, F.L., Rosenbauer, R.J., Campbell, P.L., Lam, Angela, Lorenson, T.D., Hostettler, F.D., 

Thomas, Burt, 2011, Macondo–1 well oil in sediment and tarballs from the northern Gulf of Mexico shoreline: 

U.S. Geological Survey Open–File Report 2011–1164 [http://pubs.usgs.gov/of/2011/1164/].