To study oil pollution on the surface of the Caspian Sea in the area of the ports of Aktau, Kuryk and Ersai, the archives of radar data obtained from the synthetic aperture radars of the Sentinel-1 satellite constellation belonging to the European Space Agency for the period 2013 - 2022 were selected. For this purpose, a specialized satellite information service “See the Caspian Sea” (STCS) (http://caspian.geosmis.ru) created in 2023 jointly by Space Research Institute and Shirshov Institute of Oceanology of Russian Academy of Sciences was used. This system is specifically designed for the Caspian Sea and is created on the basis of the existing “See the Sea” (STS) service, which is part of the “IKI-Monitoring” Center for Collective Use established in Space Research Institute. For a given polygon in the region of the ports of Aktau, Kuryk and Ersai, in the STCS system, time series archives consisting of more than 3,700 radar images were examined. Each image was manually analyzed to identify dark areas of reduced radar signal that could be identified as oil contamination. A total of 15 oil slicks were discovered, up to 89 km in length and up to 8 km2 in area. A satellite image of each oil slick is presented in the article, as well as its main characteristics. In addition, as part of the project “Satellite monitoring of the water areas of the ports of Aktau and Kuryk”, sea water samples were taken in the area of the ports of Aktau and Kuryk, which showed the content of oil products in the range of 0.014-0.1 mg/dm3. Thus, the resulting concentrations turned out to be less than the maximum permissible concentration of 0.1 mg per liter.
Read full abstract