Seabed classification at ocean margins

Ocean margins have become the focus of most geophysical and environmental surveys, because of their economic, scientific and oceanographic significance. These surveys deliver increasingly larger volumes of data, acquired by many types of techniques and sensors. Despite its importance, most of this data is still interpreted visually and qualitatively by skilled interpreters. Human interpretation is time-consuming and difficult to standardise; and, in certain conditions, it can be error-prone. Current research in data processing is shifting toward computer-based interpretation techniques, and in particular seafloor classification. After a brief review of the main characteristics of ocean margins, the different notions of classification will be presented, along with the desired aims. They will be followed with a review of non-acoustic and acoustic (mainly sonar) classification techniques, supplemented with actual examples when applicable. Seabed classification, in general and at ocean margins, is fast becoming a major tool in seafloor surveying and monitoring, and the last section will assess the latest tendencies, and the technical developments that can be expected in the near future.