Remote sensing and GIS-based analysis of hydrocarbon seeps: Detection, mapping, and quantification

Abstract

The thesis aims to elucidate the transport and fate of hydrocarbon emissions from deep-sea seeps through the water column towards the atmosphere. An array of hydroacoustic, satellite, and optical imaging techniques was employed to detect, map, and quantify such seeps and accompanying oil and gas emissions. The major finding is that gas transport via bubbles is the overwhelming mechanism, to transfer hydrocarbons to the hydrosphere. However, only at seeps that discharge oil and gas (oily gas bubbles) these emissions might reach the sea surface and atmosphere. At other sites gas dissolves in the water column, thus not representing a primary source of atmospheric methane and higher hydrocarbon concentrations. Therefore it is suggested to focus research on oil seeps when aiming to study the potential effect of marine hydrocarbon seeps on the present climate.