365c56287a93e7433e4d036c5844e3876ca5b375 eng Garry Baker British Geological Survey Head of BGS Data Centre +44 (0)115 936 3100 +44 (0)115 936 3200 enquiries@bgs.ac.uk British Geological Survey Environmental Science Centre Keyworth Nottingham NG12 5GG UK https://www.bgs.ac.uk/technologies/web-map-services-wms/geoindex-wms-services/ 2022-04-08T08:26:24 ISO 19115:2003/19139 1.0 CRS:84 EPSG:4326 EPSG:4258 EPSG:27700 EPSG:3857 GBR BGS Gravity anomalies grey shaded  2022-04-08T08:26:24 This low-resolution image has been produced from BGS land and marine gravity data. The colour was generated using the BGS COLMAP software package. Colour levels are defined by histogram equalisation. Combining this image with the grey shaded relief image produces a similar image to the colour shaded relief image. The measured gravity values have been corrected in order to show the anomalies attributable to variations in crustal density. In broad terms the blues are attributable to large volumes of low density rocks, the reds to high density rocks. Significant lows occur, for instance, over areas of thick, low density sedimentary rocks(e.g. Cheshire Basin, Wessex Basin), or large granites (eg Cornwall). For marine data, free-air anomalies have been calculated from observed gravity values along marine survey lines. Line intersection errors between crossing lines and overlapping surveys have been used using network adjustment techniques. Free air anomalies have been calculated for sea-bottom stations. For land data, bouguer anomalies have been calculated from gravity observations at points of known height. In order to minimise the effect of topography, Bouguer corrections for the British Mainland have been applied using a density estimated for each station. Elsewhere a correction density of 2.67 Mg/m3 has been used. Corrections for the gravitational effect of terrain have been made where significant, and in a general extent to a radius of 48.6km. The data have been interpolated onto a 1km x 1km grid using a variable tension technique, and smoothed. This layer is only available at specific zoom levels. Please zoom to a larger scale to interrogate the map. Garry Baker British Geological Survey Head of BGS Data Centre +44 (0)115 936 3100 +44 (0)115 936 3200 enquiries@bgs.ac.uk British Geological Survey Environmental Science Centre Keyworth Nottingham NG12 5GG UK https://www.bgs.ac.uk/technologies/web-map-services-wms/geoindex-wms-services/ http://onegeology-geonetwork.brgm.fr/geonetwork3/srv/api/records/365c56287a93e7433e4d036c5844e3876ca5b375/attachments/365c56287a93e7433e4d036c5844e3876ca5b375_s.png thumbnail png http://onegeology-geonetwork.brgm.fr/geonetwork3/srv/api/records/365c56287a93e7433e4d036c5844e3876ca5b375/attachments/365c56287a93e7433e4d036c5844e3876ca5b375.png large_thumbnail png Geophysics GeoIndex Gravity anomalies grey shaded OneGeology continent@Europe subcontinent@Northern Europe geographicarea@United Kingdom of Great Britain and Northern Ireland dataprovider@British Geological Survey serviceprovider@British Geological Survey DS_TOPIC@geoscientificinformation DS_DATE@2022 thematic@Geophysics thematic@Exploration thematic@Gravimetry 590587.797619 geoscientificInformation -9.291430 2.737207 49.787973 60.886884 https://map.bgs.ac.uk/arcgis/services/GeoIndex_Onshore/geophysics/MapServer/WmsServer? OGC:WMS-1.3.0-http-get-map Gravity.anomalies.grey.shaded GBR BGS Gravity anomalies grey shaded  https://metadata.bgs.ac.uk/geonetwork/srv/eng/csw?SERVICE=CSW&REQUEST=GetRecordById&ID=9df8df53-2a94-37a8-e044-0003ba9b0d98&elementSetName=full&OutputSchema=http://www.isotc211.org/2005/gmd&version=2.0.2& application/xml Gravity.anomalies.grey.shaded (MetadataURL) https://map.bgs.ac.uk/arcgis/services/GeoIndex_Onshore/geophysics/MapServer/WmsServer?request=GetLegendGraphic%26version=1.3.0%26format=image/png%26layer=Gravity.anomalies.grey.shaded image/png Gravity anomalies (grey shaded) (LegendURL)