BGS launches three-year programme to remap UK seabed geology

The British Geological Survey has begun a three-year programme to develop new national-scale geological datasets for the UK Continental Shelf, providing offshore developers with a clearer picture of seabed and shallow subsurface conditions around the country.

The Seabed Geoscience for Marine Planning project, known as Seabed GeoMaP, will combine existing geological information, marine survey data and new analytical techniques to build a more consistent understanding of the UK seabed. The work will cover themes including seabed geomorphology, Quaternary sediment thickness, sediment variability, submarine landslides and the likelihood of future seabed change.

The UK Continental Shelf extends from the country's landmass beneath the surrounding seas and supports an increasingly dense range of infrastructure. Offshore wind farms, subsea power and telecommunications cables, pipelines and other marine developments all depend on reliable information about the ground they interact with.

For projects at an early stage, better regional geological information can help identify areas of higher uncertainty before detailed site investigation begins. Variations in sediment thickness, buried geological features, unstable slopes or zones susceptible to erosion can influence where foundations are positioned, how cable routes are selected and what investigation strategy is required before design progresses.

The project is particularly relevant to subsea cables, where the shallowest metres of the seabed can strongly influence installation and long-term performance. Earlier BGS research in the North Sea indicated that the upper seabed is considerably more geologically variable than previously assumed. That variability can affect burial depth, trenching methods and exposure to hazards such as erosion, anchors and fishing activity.

Seabed GeoMaP will not replace project-specific geophysical and geotechnical investigation. Instead, it is intended to improve the regional ground model available before those investigations are designed, helping developers focus surveys more effectively and understand potential geological hazards earlier in the project lifecycle.

The datasets will also contribute to The Crown Estate's Marine Delivery Routemap, a digital planning tool intended to model future use of the seabed and coastline around England, Wales and Northern Ireland. This will support decisions where offshore energy, environmental protection and infrastructure development increasingly compete for the same marine space.

Once completed, the new information will be made available through the Marine Data Exchange and the BGS GeoIndex, allowing it to be accessed across the offshore sector rather than remaining within individual project archives.

As offshore development expands, the quality of the ground model is becoming increasingly important at the planning stage. The new mapping programme aims to provide a stronger geological baseline across the UK Continental Shelf, giving designers and developers a clearer starting point before project-specific investigation and engineering begin.