Using Envisat ASAR Images to Detect and Characterize Hydrocarbon Seeps in the Caspian Sea

Abstract:
Analysis of the GIS based oil slick distribution map created from seven Envisat ASAR images showed that the main hydrocarbon contribution in the south-west part of the Caspian Sea comes, most likely, from the seafloor mud volcanoes. In total about 100 active mud volcanoes having repeating or periodic regime were identified in this area; they are distributed widely across the south-western Azeri and western Iranian sectors. As estimated they produce up to 16,000 tonnes of crude oil per year that means a strong impact on the marine environment of the Caspian Sea. There is a link between activity of underwater mud volcanoes and intensity of earthquakes in the region. Evidently the Envisat, in its IM and WSM modes, significantly contributes to investigation the temporal and spatial variability of the phenomena related to natural seeps in the sea.