Predictor variables and groundtruth samples for north-west European continental shelf quantitative sediment analysis dataset https://portal.medin.org.uk/portal/start.php?tpc=009_CEFAS0c33c81e-43d1-4b57-9740-8d2d6833c15b Input data used to model sediment grain size for the north-west European continental shelf. Data includes: Sediment groundtruth observations with measured fractions of mud, sand and gravel, also converted to two additive log-ratios. These total 45761 samples. Also included are the eight predictor variables that were used to model sediment grain size. These were: Bathymetry, Bathymetric position index at a 50-pixel radii, Bathymetric position index at a 434-pixel radii, Distance from coast, Current speed at the seabed, Wave peak orbital velocity at the seabed, and suspended inorganic particulate matter for summer and winter as two separate variables. 20190411 20190409