GLACIAL MAP OF BRITAIN AND GIS DATABASE

We have reviewed the academic literature and British Geological Survey mapping to produce Britain’s first comprehensive ‘Glacial Map’ and accompanying geographic information system (GIS) database. The map is produced at a scale of 1;625,000. Emphasis is on information that constrains the last (Devensian) ice sheet, primarily its extent and flow geometry. Evidence relating to earlier or later glacial events is excluded. The following are included: moraines; eskers; drumlins; meltwater channels; tunnel valleys; shelf-edge fans; trimlines; limit of key glacigenic deposits (‘drift limits’); glaciolacustrine deposits, ice dammed lakes; erratic dispersal; and the main Loch Lomond Readvance limit. Offshore evidence is also included. The GIS contains over 20,000 features split into thematic layers (as above), stored as ‘shapefiles’ which are easily displayed within GIS software. Features are attributed such that they can be traced back to their published sources. Given that information included has not been collected by a systematic survey of the country but by piecemeal effort by numerous researchers over 150 years, our main caveat is that of data consistency and reliability. We have not field checked anything and merely report what has been published. It is hoped that this compilation will stimulate greater scrutiny of existing published data, assist in palaeoglaciological reconstructions of the ice sheet, facilitate greater use of field evidence in numerical ice sheet modelling experiments and help direct field workers in their future investigations.