BGS releases 10K maps through updated maps portal

As part of our continuous effort to provide more open access to our data, BGS has launched the updated BGS Maps Portal. The renewed portal provides access to over 45 000 BGS maps and sections with the following themes:

• geological
• geophysical
• geochemical
• hydrogeological

The large-scale 10 000 and 1:10 560 BGS onshore geological maps collection is included in this portal for public viewing for the first time, along with the key 1:50 000 and 1:63 360 maps of England, Wales and Scotland.

Map portal features

The new portal will allow users to view all publicly available, maps held by BGS, with quick-view thumbnail browsing and an increased number of scanned images. Users can view the collections for free; those wishing to purchase their own copy of a map can buy high-resolution PDFs through the BGS shop.

A small number of maps do not have scans; for completeness, we have provided the full catalogue with all the maps’ details, omitting image links where scans do not exist.

We hope that, by providing this enhanced service, the maps portal will better meet our users’ diverse needs. However, it is important to note that users should visit BGS’s digital dataset BGS Geology, the GeoReports service or the onshore GeoIndex to access the latest digital vector mapping. The digital vector data in these services can differ significantly from the mostly historical maps presented in the maps portal so the most up-to-date vector data should be consulted for more professional user needs.

History of geological mapping at BGS

Since BGS’s inception in 1835, our maps have evolved in differing iterations of scale. Initially surveyed and produced at the 1:63 360 (one inch to one mile) scale, the decision was made in the 1850s to carry out geological surveys at the 1:10 560 scale (six inches to one mile). This standard large-scale map scale for recording field-survey information and producing maps continued for much of BGS’s existence and was based primarily on the Ordnance Survey County Sheet lines.

The next major change came in the 1940s, when these ‘County Series’ maps began to be replaced by National Grid sheet line maps. Finally, in the late 1970s, the metric 1:10 000 scale was introduced and became the standard large-scale format for field mapping. A small number of remote areas were mapped and provided at the 1:25 000 scale.

The new 2023 to 2028 BGS Strategy ‘Understanding our Earth’ includes a renewed focus on national mapping, an aim which is supported by the renewal of the BGS Maps Portal.

One of the key science priorities identified in the new BGS Strategy focuses on the provision of geological maps and models and, in particular, ensuring that information about the underlying geology of our country is accessible. The new enhancements to the BGS Maps Portal, particularly the addition of the large-scale 1:10 000 maps and improved search features, very much align with this aim and are a significant step forward in maximising the value of our spatial data.

Dr David Schofield, BGS Director of National and International Geoscience.