Seabed Geomorphology

BGS Marine Geoscience18 Feb., 2015

(Dayton Dove and Alan Stevenson)

Seabed and shallow sub-seabed environments

Hard Substrate mapping (Gafeira et al., 2010)

Clark et al. (2012)

Glaciation of the NW European Margin

Modern, mobile sedimentation

Motivation/Objectives• Standardized map series to join existing 1:250k ‘Solid’, ‘Quaternary’, and ‘Seabed

Sediments’;

• Geomorphology may be used to distinguish feature origin– Characterize the processes which formed, and actively govern the physical seabed

environment;

• Make use of increasing availability of extensive swath bathymetry data;

• Classification should be sufficiently detailed to be useful, but not over-interpreted (mired in disputed feature definitions);

• Intention: – Maps will be enabling resources for research, education, commercial, and policy

purposes;

• Should be consistent with onshore geomorphology mapping.

Underpinning data

• Swath Bathymetry• Re-gridded single-beam

bathymetry?• Complimented by seismic,

seabed & core samples

Case Study: Glacial Geomorphology – Inner Hebrides, Scotland

• Streamlined sub-glacial features (e.g. Drumlins, crag and tail forms)

• Ice-marginal features (e.g. Moraines)

• Simple compositional description

Glacigenic landforms

Further details of proposed map seriesDigital publication via MAREMAP: http://www.maremap.ac.uk/index.html

GIS map products will be accompanied by brief documentation replicating the kind of marginalia on 1:250k paper maps (e.g. Image/Location/Date of source data, Legend, Basic and relevant environmental history of mapped region).

Each feature will have associated glossary definition.

Apart from symbolised features, further quantitative (e.g. height) and qualitative (e.g. active vs. moribund) attributes will be included;

Nominal presentation scale will be 1:50k. But other scales may be employed where required/desired.

Individual geomorphological themes (e.g. Coastal) may be published independently for a given area without requirement to map all geomorphological features.

Utilizing bespoke, standardised GIS tools developed by BGS (SIGMA) integrating interpretation, database, map production, and archiving.