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    An index to over 600 ground geophysical surveys carried out in the UK for a variety of projects. A large number of these surveys were done in conjunction with the DTI Mineral Reconnaissance Programme in the 1970's and 80's, and many others were carried out at the request of BGS field mapping groups. Information held describes the survey objective, location of measurements, geophysical methods and equipment used, reports and publications, storage locations of data and results (for analogue and digital data), dates and personnel. There are two datasets; one shows the outline of the survey areas, and the other shows the actual survey lines within each area.

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    This layer of the map based index (GeoIndex) shows the path the survey ship took whilst undertaking the ship gravity, magnetic and bathymetry survey. This index is based on data from approximately 350,000 line kilometres of multi-instrument geophysical survey lines. The data itself includes seismic, sonar, magnetic, gravity, echo sounder, multibeam bathymetry and navigation data, both in digital and analogue format. The data were primarily collected by BGS and the collection also includes additional third party data.

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    This low-resolution image has been produced from BGS airborne and marine magnetic 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. A published coloured shaded relief map, using the full resolution of the data and produced at a scale of 1: 1500 000, is available. The map covers a larger area than this image, and includes additional data from other sources. The data used to compile this image are available in various forms for academic and commercial licensing. The data from surveys covering the UK mainland have been digitised from their original analogue form. Elsewhere data were acquired digitally. Standard methods of processing were used to remove diurnal and secular variations and to minimise line intersection errors. While efforts have been made to remove artefacts from the data, some may remain between adjacent datasets. Generally anomalies over man-made structures have not been removed. The data have been interpolated onto a 1km x 1km grid using a variable tension technique, and smoothed.

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    The UK Onshore Geophysical Library was established in 1994 in conjunction with the Department of Trade and Industry (DTI) and the UK Onshore Operators Group (UKOOG). The Library manages the archive and official release of seismic data recorded over landward areas of the UK. By agreement with the DTI and HMSO, the Library operates as a registered charity, funded by revenues raised from data sales and donations, with the long term objective of bringing all available UK onshore digital seismic data into secure archival storage, whilst providing efficient access to all interested parties. BGS has access to the data at cost of copying only for science budget work. Data index on the BGS Geoscience Data Index.

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    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.

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    This layer of the map based index (GeoIndex) shows the location of onshore UK boreholes known to BGS that have digital or paper geophysical borehole logs. The details given for each borehole are, the name of the borehole, the grid reference and the format, ie. paper or digital. Scattered distribution of boreholes, locally dense coverage, few logs from Scotland. The GeoIndex is updated at regular intervals but more information may be available than is shown at any one time.

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    This layer of the map based index (GeoIndex) shows unadjusted ship gravity, magnetic and bathymetry data acquired by BGS as part of its Offshore Reconnaisance Mapping Programme. This programme commenced in 1967, and was funded mainly by the Department of Energy. Unadjusted ship gravity and bathymetry data from various commercial and academic surveys between 1965 and 1994. Confidential M.O.D Hydrographic Office integrated ship gravity and magnetics surveys of NW Europe marine areas for which BGS acts as agent. Network adjusted gravity and magnetic compilations of data from BGS and non-BGS sources.

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    Data from the British Geological Survey's GeoIndex Geophysics theme are made available for viewing here. GeoIndex is a website that allows users to search for information about BGS data collections covering the UK and other areas world wide. Access is free, the interface is easy to use, and it has been developed to enable users to check coverage of different types of data and find out some background information about the data. More detailed information can be obtained by further enquiry via the web site: www.bgs.ac.uk/geoindex.

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    Digitised version of aeromagnetic survey records of Great Britain comprising a record for each digitised point, supported by survey and 'ends and bends' based line indexes. Original records include flight line records, worksheets, contour sheets and air photos provided by contractors at completion of each survey. Worksheets digitised by BGS during 1980's Smith and Royles 1989.

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    Indexes and data records for Regional gravity observations on the UK mainland, Northern Ireland, offshore islands, tidal estuaries and seabed. Records include station identities, position, gravity reading and reduced gravity values. Most of the surveys were carried out by the BGS but the database includes data originally acquired by other organisations and subsequently given to the BGS to be managed as part of the national archive. Complete coverage of the UK mainland with a station density of 1-2 stations per square kilometre.