The GEBCO_2020 Grid - the 2020 compilation of a continuous terrain model of the global oceans and land

The GEBCO_2020 Grid is a global continuous terrain model for ocean and land with a spatial resolution of 15 arc seconds. In regions outside of the Arctic Ocean area, the grid uses as a base Version 2 of the SRTM15_plus data set (Tozer, B. et al, 2019). This data set is a fusion of land topography with measured and estimated seafloor topography. Included on top of this base grid are gridded bathymetric data sets developed by the four Regional Centers of The Nippon Foundation-GEBCO Seabed 2030 Project. The GEBCO_2020 Grid represents all data within the 2020 compilation. The compilation of the GEBCO_2020 Grid was carried out at the Seabed 2030 Global Center, hosted at the National Oceanography Centre, UK, with the aim of producing a seamless global terrain model. Outside of Polar regions, the gridded bathymetric data sets supplied by the Regional Centers, as sparse grids, i.e. only grid cells that contain data were populated, were included on to the base grid without any blending. The data sets supplied in the form of complete grids (primarily areas north of 60N and south of 50S) were included using feather blending techniques from GlobalMapper software. The GEBCO_2020 Grid has been developed through the Nippon Foundation-GEBCO Seabed 2030 Project. This is a collaborative project between the Nippon Foundation of Japan and the General Bathymetric Chart of the Oceans (GEBCO). It aims to bring together all available bathymetric data to produce the definitive map of the world ocean floor by 2030 and make it available to all. Funded by the Nippon Foundation, the four Seabed 2030 Regional Centers include the Southern Ocean - hosted at the Alfred Wegener Institute, Germany; South and West Pacific Ocean - hosted at the National Institute of Water and Atmospheric Research, New Zealand; Atlantic and Indian Oceans - hosted at the Lamont Doherty Earth Observatory, Columbia University, USA; Arctic and North Pacific Oceans - hosted at Stockholm University, Sweden and the Center for Coastal and Ocean Mapping at the University of New Hampshire, USA.

British Geological Survey (BGS) Geophysical Survey 1969/SM/9: Firth of Clyde (08/12/1969 to 18/12/1969)

This British Geological Survey (BGS) marine geophysical survey took place in December 1969 in the Firth of Clyde on board the MV Stella Maris. The purpose was to investigate the superficial deposits of the clyde area, this survey was Phase 4 of a 5 phase project. Sea floor data were collected using echosounder. Sub-bottom seismic profiling data were collected using Pinger and Sparker. These records are archived by BGS. Details of the survey are contained in IGS report 73/9.

British Geological Survey (BGS) Geophysical Survey 1971/SV/4: North Scotland and Minch (26/Jun/1971 to 21/Jul/1971)

This geophysical survey has been carried out by Marine Geophysics Unit of British Geological Survey (BGS) for BGS, the survey took place from June to July 1971 in the North Scotland and Minch area, on board the MV Surveyor. The purpose was to collect data as part of a regional mapping programme. Sea floor data were collected using Echosounder and Transit sonar. These data are archived by BGS. No BGS survey report currently available, IGS 1971 annual report contains summary.

British Geological Survey (BGS) Geophysical and Multibeam Survey 2007/1; White Ribbon Survey in Montrose Basin (20/01/2007 - 25/01/2007)

This British Geological Survey (BGS) marine geophysical and multibeam survey took place in January 2007 in the white ribbon area of the Montrose Basin on board the Kommander Iona. The purpose was to obtain the data necessary to produce a swathe bathymetry map of the inshore area, in a bid to link the nearshore and offshore geology. Sea floor bathymetry data were collected using a Reson Seabat 8101 multibeam system run by Utec Survey. Sub bottom seismic profiling data were gathered by BGS using a surface tow boomer. Most of the data were recorded digitally, but paper records were generated also. These data are archived by BGS. Technical details of the survey are contained in BGS Internal Report IR/07/025.

Natural Environment Research Council (NERC) Geophysical and Multibeam Survey 2009/6_DETI: 2D Seismic Survey, North Channel, Offshore NE Ireland (14/Sep/2009 to 28/Sep/2009)

This 2D Hi-resolution multichannel seismic survey took place September 2009 in the North Channel Basin offshore NE Ireland on board the Fugro Meridian. The survey was carried out by Fugro on behalf of Natural Environment Research Council (NERC)/Department of Enterprise, Trade and Investment (DETI). The aim was the evaluation of the potential development of offshore gas cavern storage sites in the salt formations of the Permo-Trias. These data are archived by BGS. Technical details of the survey are contained in FugroReport No.: FSLTD 29-00050 and futher information is available in the reports, A geological interpretation of the nearshore area between Belfast Lough and Cushendun, Northern Ireland, utilising a newly acquired 2D seismic dataset to evaluate salt layers for their potential for gas storage in salt caverns (http://nora.nerc.ac.uk/id/eprint/516832/) and A geomorphological interpretation of multibeam data, nearshore area between Belfast Lough and Cushendun, Northern Ireland (http://nora.nerc.ac.uk/id/eprint/530766/).

British Geological Survey (BGS) Sampling Survey 1969/MW/1: Sea of Hebrides, Clyde, Irish Sea, North Channel and Tay-Forth (06/Jun/1969 to 07/Sep/1969)

This sampling survey has been carried out by Institute of Geological Sciences now British Geological Survey (BGS) and George Wimpey and Co Ltd for BGS, the survey took place from June to September 1969 in the Sea of Hebrides, Clyde, Irish Sea, North Channel and Tay-Forth areas on board the MV Maria W. The purpose was to collect data as part of UK regional mapping programme. Sample data were collected using dredge; gravity corer; rock drill; vibrocorer; beach sampling; diver; photograph and Shipek grab. Most of these data are archived by BGS. Reference to part of the survey contained in IGS report 73/14.

British Geological Survey (BGS) Geophysical Survey 1971/S2: Peach/Tiree (21/08/1971 to 29/08/1971)

This geophysical survey has been carried out by Marine Geophysics Unit of British Geological Survey (BGS) for BGS, the survey took place from August to September 1971 in the Sea of the Hebrides area, on board the MV Surveyor. The purpose was to collect data as part of a regional mapping programme. Sea floor data were collected using Transit sonar. In September trials were carried out with a sea bed scintillation probe (SBSP), but no records available. These data are archived by BGS. No survey report currently available.

British Geological Survey (BGS) Geophysical and Sampling Survey 1976/14: North Sea and The Minch (17/Sep/1976 to 03/Oct/1976)

This British Geological Survey (BGS) regional marine geophysical and sampling survey (comprised of two legs) took place from September to October 1976 in North Sea and the Minch on board the RRS Challenger. The purpose was to gather data which could be used to map the regional geology of the area and investigate Pockmarks between the Forties and Piper oilfields (Leg 1), to recover solid rock from outcrops on the west coast of Scotland using Consub (Leg 2). Seabed samples and cores were collected using Shipek grab, Gravity corer and unmanned submersible Consub. Sea floor data were collected using a echo-sounder, side-scan sonar, acoustic and resistivity probes. These data are archived by BGS. Technical details of the survey are contained in BGS Internal Report 76/8.

The GEBCO_2021 Grid - the 2021 compilation of a continuous terrain model of the global oceans and land

The GEBCO_2021 Grid is a global continuous terrain model for ocean and land with a spatial resolution of 15 arc seconds. In regions outside of the Arctic Ocean area, the grid uses as a base, Version 2.2 of the SRTM15+ data set between latitudes of 50 degrees South and 60 degrees North. This data set is a fusion of land topography with measured and estimated seafloor topography. This version of SRTM15+ is similar to version 2.1 [Tozer et al., 2020] with minor updates. Version 2.2 uses predicted depths based on the V29 gravity model [Sandwell et al., 2019] and approximately 400 small areas containing suspect data were visually identified and removed from the grid. Included on top of this base grid are gridded bathymetric data sets developed by the four Regional Centers of The Nippon Foundation-GEBCO Seabed 2030 Project. The GEBCO_2021 Grid represents all data within the 2021 compilation. The compilation of the GEBCO_2021 Grid was carried out at the Seabed 2030 Global Center, hosted at the National Oceanography Centre, UK, with the aim of producing a seamless global terrain model. Outside of Polar regions, the gridded bathymetric data sets are supplied by the Regional Centers as sparse grids, i.e. only grid cells that contain data were populated, were included on to the base grid without any blending. The data sets supplied in the form of complete grids (primarily areas north of 60N and south of 50S) were included using feather blending techniques from GlobalMapper software. The primary GEBCO_2021 grid contains land and ice surface elevation information - as provided for previous GEBCO grid releases. In addition, for the 2021 release a version with under-ice topography/bathymetry information for Greenland and Antarctica is also available. The GEBCO_2021 Grid has been developed through the Nippon Foundation-GEBCO Seabed 2030 Project. This is a collaborative project between the Nippon Foundation of Japan and the General Bathymetric Chart of the Oceans (GEBCO). It aims to bring together all available bathymetric data to produce the definitive map of the world ocean floor by 2030 and make it available to all. Funded by the Nippon Foundation, the four Seabed 2030 Regional Centers include the Southern Ocean - hosted at the Alfred Wegener Institute, Germany; South and West Pacific Ocean - hosted at the National Institute of Water and Atmospheric Research, New Zealand; Atlantic and Indian Oceans - hosted at the Lamont Doherty Earth Observatory, Columbia University, USA; Arctic and North Pacific Oceans - hosted at Stockholm University, Sweden and the Center for Coastal and Ocean Mapping at the University of New Hampshire, USA.

Scottish Coal Company Ltd (SSC) Geophysical Survey 2009/2_SCCL: Commercial in Confidence: Scottish Coal survey of Loch Fitty (23/Mar/2009 to 25/Mar/2009)

This marine geophysical survey took place in March 2009 in Loch Fitty in Fife aboard the small outboard powered 'Tuppence' provided by ACS Coring Services. This survey was carried out by the British Geological Survey (BGS) as part of a study commissioned by Scottish Coal to ascertain the depth of sediment covering the coal seams beneath Loch Fitty. BGS personnel were also involved in the operation. Subsurface seismic data were gathered using a Surface Tow Boomer. Most of the data were recorded digitally, but paper records were generated also. These data are archived by BGS. Technical details of the survey are contained in BGS Internal Report CR/09/014.

Bathymetry and Elevation