BRITICE Glacial Mapping Project: version two release (2017)

Map showing the extent of the last British-Irish Ice Sheet

The British-Irish Ice Sheet

During the last 2.6 million years, a period of time known as the Quaternary, the climate has switched in and out of ice ages. During these ice ages, kilometer thick ice sheets covered large portions of the northern hemisphere, including Britain and Ireland. The legacy of these ice sheets can be viewed in the landscape, as they left behind numerous landforms (geomorphology) that allows us to piece together the extent and geometry of the ice sheets.

The aim of the BRITICE project is to bring together published information regarding the geomorphology (landforms) of the last British-Irish ice sheet.

The compiled record will help us better understand how ice sheets work. This is critical, as the ice sheets which currently exist in Greenland and Antarctica are losing mass at an accelerating rate. This ice ends up in the sea, raising global sea levels. The record of a past ice sheet provided by BRITICE enables scientists to study how an ice sheet that disappeared in the past reacted to a changing climate.

We hope that the compilation will:

  • Showcase glacial geomorphology and the ice sheet to schools and the wider community
  • Stimulate greater scrutiny of published data
  • Facilitate use of field-evidence in numerical ice sheet modelling
  • Help direct field-workers in their future investigations


Overview of the BRITICE mapCompiling more than 100 years of research

The imprint of the last ice sheet on Britain and Ireland has been studied for over 100 years. During this time, scientists conducting fieldwork and mapping from satellite data and aerial photography produced geomorphological (landform) maps, documenting the distribution of landforms left behind by the ice sheet. 

We reviewed over 1,800 publications from the academic literature, British Geological Survey and Irish Geological Survey mapping. Relevant data from each published map were compiled into a geographic information system (GIS). 

Version 1 of the BRITICE project was completed in 2004. The data relating to version 1 can be found here.

Version 2 includes mapping updated from 2004. This revised database contains over 170,000 landforms. This is 8 times the amount of information than was available in version 1. The database now includes Ireland. This increase has been facilitated by advances in technology, such as high-resolution digital elevation models of the land and seabed, as well as continued fieldwork. In some cases, this means that mapping of the same feature has been repeated. Therefore, creation of a "filtered database" required the removal of such instances. All data is retained for reference in the "unfiltered database". The high density of data mean that sensibly sized maps which show all of the data are difficult to produce (they would have to be 5 m by 5 m in size!). In order to see the full detail of the mapping, you need to consult the filtered database, and the three pdf maps which are designed to be digitally viewed at a scale of 1:200,000. In We therefore created a "generalised map" which shows a cartographically reduced representation of the data, suitable for printing at A0 size at a 1:1,250,000 scale. 

Available products:

  • A filtered GIS database, resolving data conflicts and with edits to improve geo-locational accuracy (available as GIS data and PDF maps)
  • Cartographically generalised map to provide an overview of distribution and types of features at the ice-sheet scale (A0 size PDF).
  • Unfiltered GIS database containing all mapping

What is included?

Moraines

Accumulations of sediment with a topographic expression recording an ice margin position.

Map of moraine ridges near York

Subglacial lineations

Streamlined landforms primarily composed of drift, formed at the sole of the ice sheet, orientated in the direction of ice flow. Includes drumlins and mega-scale glacial lineations.

Digital elevation model of some drumlins

Subglacial ribs

Ridges formed at the base of the ice sheet, transverse to flow direction. Previously known as ribbed or Rogen moraine, the word moraine being misleading as they are known not to record ice marginal positions.

Aerial view of some subglacial ribs

Crag and tails

Bedrock hills (crags) with tapering sediment ridges (tails). The tails are usually formed in the lee of crags, extending in a down-ice direction.

Digital elevation model of some crag and tails in Scotland

Glacially-streamlined bedrock

Includes roches moutonées, whalebacks, rock drumlins and mega-grooves.

Photograph of a roches moutonée

Erratics

Rocks or clasts of a different type than the surrounding native bedorck, presumed to have been transported by the flow of ice.

An erratic boulder

Trough mouth fans

Glacially-fed fan or delta-like accumulations of sediment occuring at mouths of glacial troughs at the continental shelf edge.

Meltwater channels

Channels cut by glacial meltwater. Includes lateral, marginal, proglacial and subglaciall channels, as well as tunnel valleys.

Lateral meltwater channels

Eskers

Elongate ridges of glaciofluvial sediment deposited in subglacial meltwater pipes.

Photograph of an esker, made of sands and gravels

Cirques

Glacially-eroded armchair chaped hollows incicised into mountains. Also known as corries or cwms.

Photograph of Cadair Idris, a cirque with steep sides and a lake (tarn) in its centre

Ice-dammed lakes

The extent of proglacial lakes inferred from a combination of lake deposit distribution and topography.


Future updates

The census date for this version of the map was 2015, and so anything published after this time is not included. However, it is inevitable that some information may be missing, and we hope to update the map periodically. 

Other mapping may have been included in the "unfiltered" database, but excluded from the final map due to repeat mapping.

If you have any extra information, critisms or suggested amendments please contact Chris Clark (c.clark@sheffield.ac.uk) who will ensure they are considered for the next update.