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Ubiquitous tar balls with a California-source signature on the shorelines of Prince William Sound, Alaska

February 3, 1995

Although the shorelines of Prince William Sound still bear traces of the 1989 Exxon Valdez oil spill, most of the flattened tar balls that can be found today on these shorelines are not residues of Exxon Valdez oil. Instead, the carbon-isotopic and hydrocarbonbiomarker signatures of 61 tar ball samples, collected from shorelines throughout the northern and western parts of the sound, are all remarkably similar and have characteristics consistent with those of oil products that originated from the Monterey Formation source rocks of California. The carbonisotopic compositions of the tar balls are all closely grouped (<513Cpdb = -23.7 ± 0.2%o), within the range found in crude oils from those rocks, but are distinct from isotopic compositions of 28 samples of residues from the Exxon ValdezoW spill (<513Cpdb = -29.4 ± 0.1%o). Likewise, values for selected biomarker ratios in the tar balls are all similar but distinct from values of residues from the 1989 oil spill. Carbon-isotopic and biomarker signatures generally relate the tar balls to oil products used in Alaska before ~1970 for construction and pavements. How these tar balls with such similar geochemical characteristics became so widely dispersed throughout the northern and western parts of the sound is not known with certainty, but the great 1964 Alaska earthquake was undoubtedly an important trigger, causing spills from ruptured storage facilities of California-sourced asphalt and fuel oil into Prince William Sound.

Citation Information

Publication Year 1995
Title Ubiquitous tar balls with a California-source signature on the shorelines of Prince William Sound, Alaska
DOI 10.1021/es00010a033
Authors Keith A. Kvenvolden, Frances D. Hostettler, P. R. Carlson, John B. Rapp, C.N. Threlkeld, Augusta Warden
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Science & Technology
Series Number
Index ID 70208290
Record Source USGS Publications Warehouse
USGS Organization Pacific Coastal and Marine Science Center