South West Deeps East interpolated map

This map was created by JNCC by combining UKSeaMap 2025 biological zones with a sediment map created using inverse distance weighting to interpolate between sediment samples. The sediment data was in the form of % sand, % mud and % gravel obtained from particle size analysis of grab samples, collated by JNCC and BGS to form the UK PSA database used in BGS Predictive Seabed Sediments (UK) modelling (Dove et al, 2025). This site includes negligible quantities of mud, meaning that the interpolation could be carried out on a single variable - in this case the % sand - and the rest was inferred to be gravel. The proportions were converted into the sediment classes used in the Marine Habitat Classification for Britain and Ireland, which, uses a 4:1 sand:mud ratio to distinguish sandy habitat from muddy habitat.