Amplified sediment waves in the Irish Sea (AMSEDIS)

Very large and extremely large sediment waves (> 3 and >18m in height resp.) are striking yet insufficiently understood seabed features in many shelf seas. Their development and migration remains problematic to model due to the number of parameters involved and the sparseness of targeted field data to validate predictions against. In addition, exceptionally high sediment waves have recently been observed on shelf seas world-wide and reach unique heights of up to 36 m in the Irish Sea. It is uncertain how the interplay between geological, biogeochemical and hydrodynamic processes influences the migration and extreme growth of these sediment waves. AmSedIS thus sets out to (1) study carbonate formation due to methane oxidation in gas seepage and establish its association with extreme sediment wave growth and to (2) quantify the role of sediment grain size and sorting on both “extreme” and “normal” sediment wave development. In the Irish Sea, both gas seepage and extremely high sediment waves (up to 36m high) have been documented, often even in the same area.