Map based index (GeoIndex) gravity anomalies
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.
dataset
https://map.bgs.ac.uk/arcgis/services/GeoIndex_Onshore/geophysics/MapServer/WMSServer?
name: Geophysics map theme
description: The wms layer for 'GeoIndex gravity anomalies' is held within the 'Geophysics' theme WMS layer which this URL connects to.
function: download
http://mapapps2.bgs.ac.uk/geoindex/home.html?layer=BGSGravAnom
name: GeoIndex gravity anomalies
function: information
http://mapapps2.bgs.ac.uk/geoindex/home.html?layer=BGSGravAnomGrey
name: GeoIndex gravity anomalies (grey shaded)
function: information
http://mapapps2.bgs.ac.uk/geoindex/home.html?layer=BGSGravCol
name: GeoIndex gravity anomalies (colour shaded)
function: information
http://data.bgs.ac.uk/id/dataHolding/13605466
eng
Data is visible at map scales above 1:250 000 scale.
geoscientificInformation
publication
2008-06-01
UK Location (INSPIRE)
Scottish SDI
Gravity anomalies
Geophysics
Gravity values
revision
2022
NERC_DDC
-7.5600
2.0000
60.8400
49.7600
revision
2009
GBN
creation
1979
GREAT BRITAIN [id=139600]
2014-01
creation
2000
asNeeded
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. Line intersection errors between crossing lines and overlapping surveys have been dealt with 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.
publication
2011
false
See the referenced specification
publication
2010-12-08
false
See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF
The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.
British Geological Survey
Environmental Science Centre, Nicker Hill, Keyworth
NOTTINGHAM
NG12 5GG
United Kingdom
0115 936 3143
0115 936 3276
distributor
British Geological Survey
Environmental Science Centre, Nicker Hill, Keyworth
NOTTINGHAM
NG12 5GG
United Kingdom
0115 936 3143
0115 936 3276
pointOfContact
British Geological Survey
Environmental Science Centre,Keyworth
NOTTINGHAM
NG12 5GG
United Kingdom
+44 115 936 3100
pointOfContact
2024-04-11