A new seabed mobility index for the Irish Sea: Modelling seabed shear stress and classifying sediment mobilisation to help predict erosion, deposition, and sediment distribution

The seafloor is increasingly being used for siting renewable energy and telecommunication infrastructure as well supporting key fisheries biodiversity. Understanding seabed stability sediment dynamics is, therefore, a fundamental need offshore engineering geoscience biological studies. In this study we aim to quantify the levels of mobility in Irish Sea: an area increasing socio-economic interest subsequent pressures. temporal spatial interaction between bathymetry, hydrodynamics sediments leads complex pattern erosion, bedload transport deposition which can affect modify habitats. Information on current wave conditions were obtained from numerical modelling assess their role generating hydrodynamic conditions. These outputs coupled with observed grain-size data predict exceedance thresholds by bed shear stress values period one year according empirical formulae. Exceedance frequency calculate number disturbance indexes allow robust assessment dynamics. Sediment sea, average, mobilised 35% time during year, studied over 50% time. Even areas low mobilisation (<5%), there are implications bedform patterns calculated discussed context geomorphology both environmental considerations.