Key information
Scale:
1:10 000 – 1:50 000Coverage:
RegionalAvailability:
FreeFormat:
Free to view via online map viewerUses:
Regional-level useGet data
Free access
The maps are free to view online via the BGS Offshore GeoIndex
Offshore GeoIndexSupporting documents
User guides are available via the links in the map series in the table further down the page below.
BGS has initiated a new programme of mapping the seabed geology of the UK’s continental shelf, the first effort to consistently characterise the geology of the seabed in over 20 years. These new, fine-scale maps provide detailed and accurate characterisation of the seabed geology, integrating substrate geology, structural geology and seabed geomorphology.

Dark blue area shows the coverage of the BGS Seabed Geology 10K: offshore Yorkshire map. Background image from World Ocean Base dataset compiled by Esri, Garmin, GEBCO, NOAA NGDC, and other contributors. Basemap created using ArcGIS. Copyright © Esri. All rights reserved. www.esri.com

Dark blue area shows the coverage of the BGS Seabed Geology 10K: East Anglia. Background image from World Ocean Base dataset compiled by Esri, Garmin, GEBCO, NOAA NGDC, and other contributors. Basemap created using ArcGIS. Copyright © Esri. All rights reserved. www.esri.com
The digital maps are intended as resources to support a diverse range of offshore activities and applications, including scientific research, offshore development, conservation initiatives and marine spatial planning and management.
The new mapping is based primarily on high-resolution bathymetry data produced by the UK Civil Hydrography Programme (CHP). Analysis and interpretation are further informed by secondary data and information resources, including:
- acoustic backscatter
- physical samples (for example grabs, cores and boreholes)
- seismic data
- academic and publicly accessible industry data and literature
- previous BGS mapping (onshore and offshore)
The CHP is administered by the Maritime and Coastguard Agency (MCA), with technical oversight, data validation and onward charting undertaken by the UK Hydrographic Office (UKHO).

BGS Seabed Geology 10K: Anglesey map, showing geomorphology layers (lines and points), structural geology, substrate geology and hillshade. Contains OS data © Crown Copyright and database right 2020. The underlying hillshade image is derived from bathymetric data acquired by the MCA © Crown Copyright 2022, released under OGL.

Section of the BGS Seabed Geology 10K: Anglesey map, showing geomorphology layers (lines and points), structural geology and substrate geology. Contains OS data © Crown Copyright and database right 2020.

Section of the BGS Seabed Geology 10k: Anglesey map, showing geomorphology layers (lines and points) and hillshade. Contains OS data © Crown Copyright and database right 2020. The underlying hillshade image is derived from bathymetric data acquired by the MCA © Crown Copyright 2022, released under OGL.

Section of the BGS Seabed Geology 10k: Anglesey map, showing bathymetry data (depth and hillshade). Contains OS data © Crown Copyright and database right 2020. The underlying hillshade image is derived from bathymetric data acquired by the MCA © Crown Copyright 2022, released under OGL.

Section of the BGS Seabed Geology 10k: Anglesey map, showing geomorphology layers (lines and points), structural geology, substrate geology and hillshade. Contains OS data © Crown Copyright and database right 2020. The underlying hillshade image is derived from bathymetric data acquired by the MCA © Crown Copyright 2022, released under OGL.
Product summary
The new fine-scale BGS Seabed Geology mapping comprise three complimentary components (or layers):
- substrate geology: distribution of bedrock and superficial geological units interpreted to be dominant within the top 1 m below seabed
- structural geology: principal structural features such as faults and folds observed at rockhead
- seabed geomorphology: physical morphology and interpreted geomorphic character of the seabed
Further detail on the mapping process and dataset characteristics are described within individual dataset user guides.

Available fine-scale maps
The BGS Seabed Geology maps can be viewed under the BGS fine-scale maps drop-down menu within the Offshore Geoindex.
* Bedrock and structural geology only. The Dorset map was produced under the auspices of the Marine Environmental Mapping Programme (MAREMAP), in collaboration between BGS and the University of Southampton.
Relative topics
Related news

Why do we store geological core?
11/09/2025
With space at a premium and the advance of new digitisation techniques, why does retaining over 600 km of physical specimens remain of national importance?

PhD adventures in the Philippines: coring around Lake Bulusan
05/09/2025
Chris Bengt recounts his two-week field trip to Bulusan Volcano Natural Park in the Philippines to collect lake sediment cores, fresh soil and water samples.

New seabed sediment maps reveal what lies beneath the waves
03/09/2025
Marine ecosystem science and offshore infrastructure will be boosted by a new dataset showing sediment composition across the UK continental shelf.

New geological ‘pathways’ discovered beneath Welsh capital
02/09/2025
Scientists have discovered cavities in the clay underneath Cardiff, which will influence the siting of future geothermal developments.

Seabed sediments 250K
The 1:250 000-scale offshore geological maps for seabed sediments are available digitally.

Offshore bedrock 250K
The 1:250 000-scale offshore geological map for bedrock geology (BGS Geology: marine bedrock 250k) is available digitally.

BGS artificial ground data: what do you need from a geological survey?
28/08/2025
BGS is seeking user feedback on artificial ground data: how you use it, what information you consider, and what we can do to improve our offering.

New research published on brownfield land
27/08/2025
National Brownfield Forum research on the interactions of policies affecting the planning and development of brownfield land has been published.

Join our consortium – de-risking underground thermal energy storage
25/08/2025
BGS is inviting interested parties to investigate how site-scale geological data can be used to optimise thermal storage scheme performance.

Dr Kathryn Goodenough appointed as honorary professor by the University of Aberdeen
25/08/2025
Dr Goodenough will take up the position within the School of Geosciences with a focus on critical minerals and the energy transition.

Gemini: a new stable isotope tool
21/08/2025
BGS’s Stable Isotope Facility has new mass spectrometer equipment for analysing carbon and oxygen isotopes from carbonates and water.
You may also be interested in:

Sea floor: marine geoscience
Providing independent and expert geological advice, research and data acquisition to anyone working in the marine environment.