Trajectory Analysis for the Exxon Valdez: Hindcast Study

Autor: Glen Watabayashi, J. C. Petersen, D. L. Payton, J. A. Galt
Rok vydání: 1991
Předmět:
Zdroj: International Oil Spill Conference Proceedings. 1991:629-634
ISSN: 2169-3358
2169-3366
DOI: 10.7901/2169-3358-1991-1-629
Popis: The movement and spreading of the oil from the tanker Exxon Valdez accident was a vital issue in the massive response activities launched by industry, private groups, state governments and the federal government. To address this issue, a number of observational and forecast programs were carried out. These accumulated an unprecedented amount of observational data ranging from visual and remote-sensing distribution information to fairly complex adaptations of standard trajectory analysis routines. This paper reports on a hindcast study that used observational data and computational procedures to provide a quantitative estimate of the oil distribution over time. The major difficulty in doing this work was associated with the fact that both the observational and computational data had errors. Typically, the observational distribution data were nonquantitative and tended to have a number of false positives, while the wind and current data used in the computational procedure lacked detail or were improperly scaled. To reconcile these difficulties, a statistical procedure was developed that helped identify various types of errors. This procedure was used to produce an observationally corrected, mass-balanced trajectory hindcast model. The results of the hindcast model are available in a variety of formats and indicate the following general conclusions: by the end of the second week of April, approximately 30 percent of the spilled oil may have been lost to weathering processes, 40 percent beached within Prince William Sound, 25 percent exited Prince William Sound, and about 5 percent remained floating within Prince William Sound. Further analysis indicates that, of the oil leaving the Prince William Sound system, approximately 10 percent traveled beyond Gore Point, and about 2 percent got as far as Shelikof Strait.
Databáze: OpenAIRE