This dataset contains 25m resolution raster formatted data derived from the Centre of Ecology and Hydrology's (CEH) Land Cover Map 2000 (LCM2000) data for the Thorney Island, South Coast of England, UK, NCAVEO calibration/validation (cal/val) test site. The NERC funded Network for Calibration and Validation of EO (NCAVEO) campaign was designed to illustrate and explain the processes involved in cal/val of earth observation data.

This dataset contains level 2 vector formatted data derived from the Centre of Ecology and Hydrology's (CEH) Land Cover Map 2000 (LCM2000) data for the Thorney Island, South Coast of England, UK, NCAVEO calibration/validation (cal/val) test site. The NERC funded Network for Calibration and Validation of EO (NCAVEO) campaign was designed to illustrate and explain the processes involved in cal/val of earth observation data.

A Natural England commissoined verification survey of intertidal sediments within the Thanet Coast rMCZ. Phase I Biotope mapping was carried out across the rMCZ for broad scale habitats. The data was used to produce a EUNIS Level 3 boradscale habitat map of the Thanet Coast rMCZ.

This dataset consists of the 1km raster, dominant aggregate class version of the Land Cover Map 1990 (LCM1990) for Great Britain. The 1km dominant coverage product is based on the 1km percentage product and reports the aggregated habitat class with the highest percentage cover for each 1km pixel. The 10 aggregate classes are groupings of 21 target classes, which are based on the Joint Nature Conservation Committee (JNCC) Broad Habitats, which encompass the entire range of UK habitats. The aggregate classes group some of the more specialised classes into more general categories. For example, the five coastal classes in the target class are grouped into a single aggregate coastal class. This dataset is derived from the vector version of the Land Cover Map, which contains individual parcels of land cover and is the highest available spatial resolution. LCM1990 is a land cover map of the UK which was produced at the UK Centre for Ecology & Hydrology by classifying satellite images (mainly from 1989 and 1990) into 21 Broad Habitat-based classes. It is the first in a series of land cover maps for the UK, which also includes maps for 2000, 2007, 2015, 2017, 2018 and 2019. LCM1990 consists of a range of raster and vector products and users should familiarise themselves with the full range (see related records, the UK CEH web site and the LCM1990 Dataset documentation) to select the product most suited to their needs. This work was supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability. Full details about this dataset can be found at https://doi.org/10.5285/84c07c67-88a4-439a-a339-b0577afd3886

The HABMAP project was set up in response to the need for better spatial awareness of habitat distributions in the Southern Irish Sea. This work produced habitat maps of the seabed using novel predictive modelling techniques. This dataset is related to the predictive modelling only. The HABMAP Extension Project has built on the methods developed during the original project, and has repeated the modelling work using higher resolution / improved input datasets to help increase the accuracy of the predictive map outputs. The modelling work has also been extended to cover all of Welsh waters (previously cut-off at the Interreg funding boundary), notably including the Dee and Severn estuaries. The purpose of this data capture was to provide seabed habitat maps that could be used for con servation and management. Project outputs might be used in strategic planning, decision making for offshore developments, Marine Protected Area selection, sensitivity mapping and mapping essential fish habitats. However, because of the way the has been produced, and the fact that some data has been modelled and derived, the maps are not appropriate to act as the sole evidence for any specific planning or regulatory decision or assessment without further supporting studies or evidence.

The project boundaries were as follows: Southern Irish Sea- land-based boundaries include the whole Welsh coast to the English border on the east side of the Dee Estuary in the north, and the whole Severn Estuary and Bristol Channel coastline in the south, extending as far as Morte Point (east of Ifracombe) in England. The southern project boundary then extends offshore (skirting the northern tip of Lundy) across to a point approximate 60km west of Waterford on the Irish coast, including the whole SE Ireland coastline and offshore banks as well as parts of the Celtic Sea. The boundary then extends northwards along the Irish coast to a point approximately 40 km north of Dublin.

Coastline for area between 50degS and 60degS. Data published to support the Antarctic Digital Database (ADD) web map visualisation. South Georgia and the South Sandwich Islands taken from the South Georgia GIS (https://sggis.gov.gs/). All other data from Natural Earth ''Land'' and ''Minor Islands'' v4.1.0 1:10m scale shapefiles (https://www.naturalearthdata.com/). Data compiled, managed and distributed by the Mapping and Geographic Information Centre, British Antarctic Survey.

The HABMAP project was set up in response to the need for better spatial awareness of habitat distributions in the Southern Irish Sea. This work produced habitat maps of the seabed using novel predictive modelling techniques. This dataset is related to the predictive modelling only. The HABMAP Extension Project has built on the methods developed during the original project, and has repeated the modelling work using higher resolution / improved input datasets to help increase the accuracy of the predictive map outputs. The modelling work has also been extended to cover all of Welsh waters (previously cut-off at the Interreg funding boundary), notably including the Dee and Severn estuaries. The purpose of this data capture was to provide seabed habitat maps that could be used for conservation and management. Project outputs might be used in strategic planning, decision making for offshore developments, Marine Protected Area selection, sensitivity mapping and mapping essential fish habitats. However, because of the way the has been produced, and the fact that some data has been modelled and derived, the maps are not appropriate to act as the sole evidence for any specific planning or regulatory decision or assessment without further supporting studies or evidence. The project boundaries were as follows: Southern Irish Sea- land-based boundaries include the whole Welsh coast to the English border on the east side of the Dee Estuary in the north, and the whole Severn Estuary and Bristol Channel coastline in the south, extending as far as Morte Point (east of Ifracombe) in England. The southern project boundary then extends offshore (skirting the northern tip of Lundy) across to a point approx 60km west of Waterford on the Irish coast, including the whole SE Ireland coastline and offshore banks as well as parts of the Celtic Sea. The boundary then extends northwards along the Irish coast to a point approximately 40 km north of Dublin. The outputs of the project included a Combined Level3/Level4 habitat map, presented here after translation to the EUNIS habitat classification system from the Marine Habitat Classification System for Britain and Ireland. Each polygon of the original output contained up to 46 different biotopes, either predicted by the model or recorded as present, and presented in order of likelihood. Only the primary biotope has been taken from the original dataset to produce this EUNIS output, polygons originally containing more than one habitat are flagged in the "VAL_COMM" field. Information on whether the biotope was recorded as present or was a predictive output of the model, and a confidence value present in the original dataset have also been recorded in the "VAL_COMM" field

This map shows the extents of the various datasets comprising the World Elevation dynamic (Terrain, TopoBathy) and tiled (Terrain 3D, TopoBathy 3D, World Hillshade, World Hillshade (Dark)) services.The map has pop-ups defined. Click anywhere on the map to reveal details about the data sources.Topography sources listed in the table below are part of Terrain, TopoBathy, Terrain 3D, TopoBathy 3D, World Hillshade and World Hillshade (Dark), while bathymetry sources are part of TopoBathy and TopoBathy 3D only. Data Source Native Pixel Size Approximate Pixel Size (meters) Coverage Primary Source Country/Region

Topography

Australia 1m 1 meter 1 Partial areas of Australia Geoscience Australia Australia

Moreton Bay, Australia 1m 1 meter 1 Moreton Bay region, Australia Moreton Bay Regional Council Australia

New South Wales, Australia 5m 5 meters 5 New South Wales State, Australia DFSI Australia

SRTM 1 arc second DEM-S 0.0002777777777779 degrees 31 Australia Geoscience Australia Australia

Burgenland 50cm 0.5 meter 0.5 Burgenland State, Austria Land Burgenland Austria

Upper Austria 50cm 0.5 meter 0.5 Upper Austria State, Austria Land Oberosterreich Austria

Austria 1m 1 meter 1 Austria BEV Austria

Austria 10m 10 meters 10 Austria Geoland Austria

Canada HRDEM 1m 1 meter 1 Partial areas of the southern part of Canada Natural Resources Canada Canada

Canada HRDEM 2m 2 meters 2 Partial areas of the southern part of Canada Natural Resources Canada Canada

Denmark 40cm 0.4 meter 0.4 Denmark SDFE Denmark

Denmark 10m 10 meters 10 Denmark SDFE Denmark

England 2m 2 meters 2 70 % of England Environment Agency England

Estonia 1m 1 meter 1 Estonia Estonian Land Board Estonia

Estonia 5m 5 meters 5 Estonia Estonian Land Board Estonia

Estonia 10m 10 meters 10 Estonia Estonian Land Board Estonia

Finland 2m 2 meters 2 Finland NLS Finland

Finland 10m 10 meters 10 Finland NLS Finland

Berlin 1m 1 meter 1 Berlin State, Germany Geoportal Berlin Germany

Hamburg 1m 1 meter 1 Hamburg State, Germany LGV Hamburg Germany

Nordrhein-Westfalen 1m 1 meter 1 Nordrhein-Westfalen State, Germany Land NRW Germany

Sachsen-Anhalt 2m 2 meters 2 Sachsen-Anhalt State, Germany LVermGeo LSA Germany

Hong Kong 50cm 0.5 meter 0.5 Hong Kong CEDD Hong Kong SAR

Italy TINITALY 10m 10 meters 10 Italy INGV Italy

Japan DEM5A *, DEM5B * 0.000055555555 degrees 5 Partial areas of Japan GSI Japan

Japan DEM10B * 0.00011111111 degrees 10 Japan GSI Japan

Latvia 1m 1 meter 1 Latvia Latvian Geospatial Information Agency Latvia

Latvia 10m 10 meters 10 Latvia Latvian Geospatial Information Agency Latvia

Latvia 20m 20 meters 20 Latvia Latvian Geospatial Information Agency Latvia

Lithuania 1m 1 meter 1 Lithuania NZT Lithuania

Lithuania 10m 10 meters 10 Lithuania NZT Lithuania

Netherlands (AHN3/AHN4) 50cm 0.5 meter 0.5 Netherlands AHN Netherlands

Netherlands (AHN3/AHN4) 10m 10 meters 10 Netherlands AHN Netherlands

New Zealand 1m 1 meter 1 Partial areas of New Zealand Land Infromation New Zealand (Sourced from LINZ. CC BY 4.0) New Zealand

Northern Ireland 10m 10 meters 10 Northern Ireland OSNI Northern Ireland

Norway 10m 10 meters 10 Norway NMA Norway

Poland 1m 1 meter 1 Partial areas of Poland GUGIK Poland

Poland 5m 5 meters 5 Partial areas of Poland GUGIK Poland

Scotland 1m 1 meter 1 Partial areas of Scotland Scottish Government et.al Scotland

Slovakia 10m 10 meters 10 Slovakia GKÚ Slovakia

Slovenia 1m 1 meter 1 Slovenia ARSO Slovenia

Madrid City 1m 1 meter 1 Madrid city, Spain Ayuntamiento de Madrid Spain

Spain 2m (MDT02 2019 CC-BY 4.0 scne.es) 2 meters 2 Partial areas of Spain IGN Spain

Spain 5m 5 meters 5 Spain IGN Spain

Spain 10m 10 meters 10 Spain IGN Spain

Varnamo 50cm 0.5 meter 0.5 Varnamo municipality, Sweden Värnamo Kommun Sweden

Canton of Basel-Landschaft 25cm 0.25 meter 0.25 Canton of Basel-Landschaft, Switzerland Geoinformation Kanton Basel-Landschaft Switzerland

Grand Geneva 50cm 0.5 meter 0.5 Grand Geneva metropolitan, France/Switzerland SITG Switzerland and France

Switzerland swissALTI3D 50cm 0.5 meter 0.5 Switzerland and Liechtenstein swisstopo Switzerland and Liechtenstein

Switzerland swissALTI3D 10m 10 meters 10 Switzerland and Liechtenstein swisstopo Switzerland and Liechtenstein

OS Terrain 50 50 meters 50 United Kingdom Ordnance Survey United Kingdom

3DEP 1m 1 meter 1 Partial areas of the conterminous United States, Puerto Rico USGS United States

NRCS 1m 1 meter 1 Partial areas of the conterminous United States NRCS USDA United States

FEMA LiDAR DTM 3 meters 3 Partial areas of the conterminous United States FEMA United States

NED 1/9 arc second 0.000030864197530866 degrees 3 Partial areas of the conterminous United States USGS United States

3DEP 5m 5 meters 5 Alaska, United States USGS United States

NED 1/3 arc second 0.000092592592593 degrees 10 conterminous United States, Hawaii, Alaska, Puerto Rico, and Territorial Islands of the United States USGS United States

NED 1 arc second 0.0002777777777779 degrees 31 conterminous United States, Hawaii, Alaska, Puerto Rico, Territorial Islands of the United States; Canada and Mexico USGS United States

NED 2 arc second 0.000555555555556 degrees 62 Alaska, United States USGS United States

Wales 2m 2 meters 2 70 % of Wales Natural Resources Wales Wales

WorldDEM4Ortho 0.00022222222 degrees 24 Global (excluding the countries of Azerbaijan, DR Congo and Ukraine) Airbus Defense and Space GmbH World

SRTM 1 arc second 0.0002777777777779 degrees 31 all land areas between 60 degrees north and 56 degrees south except Australia NASA World

EarthEnv-DEM90 0.00083333333333333 degrees 93 Global N Robinson,NCEAS World

SRTM v4.1 0.00083333333333333 degrees 93 all land areas between 60 degrees north and 56 degrees south except Australia CGIAR-CSI World

GMTED2010 7.5 arc second 0.00208333333333333 degrees 232 Global USGS World

GMTED2010 15 arc second 0.00416666666666666 degrees 464 Global USGS World

GMTED2010 30 arc second 0.0083333333333333 degrees 928 Global USGS World

Bathymetry

Canada west coast 10 meters 10 Canada west coast Natural Resources Canada Canada

Gulf of Mexico 40 feet 12 Northern Gulf of Mexico BOEM Gulf of Mexico

MH370 150 meters 150 MH370 flight search area (Phase 1) of Indian Ocean Geoscience Australia Indian Ocean

Switzerland swissBATHY3D 1 - 3 meters 1, 2, 3 Lakes of Switzerland swisstopo Switzerland

NCEI 1/9 arc second 0.000030864197530866 degrees 3 Puerto Rico, U.S Virgin Islands and partial areas of eastern and western United States coast NOAA NCEI United States

NCEI 1/3 arc second 0.000092592592593 degrees 10 Partial areas of eastern and western United States coast NOAA NCEI United States

CRM 1 arc second (Version 2) 0.0002777777777779 degrees 31 Southern California coast of United States NOAA United States

NCEI 1 arc second 0.0002777777777779 degrees 31 Partial areas of northeastern United States coast NOAA NCEI United States

CRM 3 arc second 0.00083333333333333 degrees 93 United States Coast NOAA United States

NCEI 3 arc second 0.00083333333333333 degrees 93 Partial areas of northeastern United States coast NOAA NCEI United States

USGS CoNED 1 - 3 meters 1, 2, 3 Partial coastal areas of eastern and western United States USGS United States

GEBCO 2021 ** 0.00416666666666666 degrees 464 Global GEBCO World

GEBCO 2014 0.0083333333333333 degrees 928 Global GEBCO World * Fundamental Geospatial Data provided by GSI with Approval Number JYOU-SHI No.1239 2016. ** GEBCO Compilation Group (2021) GEBCO 2021 Grid (doi:10.5285/c6612cbe-50b3-0cff-e053-6c86abc09f8f) *** Bathymetry datasets are part of TopoBathy and TopoBathy3D services only.Disclaimer: Data sources are not to be used for navigation/safety at sea and in air.

This service contains various Aquaculture data. This includes Shellfish Production, Optimum Sites of Aquaculture potential (AQ1), Bivalve Classification area and Areas of Future Potential for Aquaculture. ------------------------------------------------------------------------------------------------------------The Shellfish Production dataset shows shellfish farm species production data grouped by water body. Water bodies were taken from the water framework directive (WFD) coastal and transitional water bodies database, and joined with the data from CEFAS. Data contains information on species present and production values. This dataset was created by ABPmer under contract to DEFRA (Contract reference MB106). An Excel spreadsheet was supplied to ABPmer by CEFAS which contained a list of waterbodies with the species cultivated per waterbody, production per waterbody and the number of businesses operating for 2007. The production data was joined to a shapefile containing waterbodies based on name of waterbody, and all sites where no shellfish cultivation occurred were removed. The same procedure was repeated with the data of species present. A shapefile containing both number of species grown and tonnes produced per waterbody was created by merging the two datasets based on waterbody name. ------------------------------------------------------------------------------------------------------------The Optimum Sites of Aquaculture Potential (AQ1) dataset shows areas identified through GIS modelling of suitable environmental conditions in East Coast Inshore and Offshore Marine Plan Areas favourable for macroalgae culture, Bivalve Bottom Culture, Finfish Cage, Lobster Restocking, Rope Cultured Bivalve Shellfish or Trestle/Bag Culture of Bivalves. This dataset has been derived from of a wider study assessing aquaculture potential in the South and East Marine Plan Areas for the Marine Management Organisation, project MMO1040. It was created using the Natural Resource model which forms part of the MMO project 1040 Spatial Trends in Aquaculture Potential in the South and East Coast Inshore and Offshore Marine Plan Areas. The Natural Resource model is made up of three existing environmental datasets: bathymetry derived from the Department of Food and Rural Affairs (Defra) Digital Elevation Model (DEM), predicted seabed sediments and combined seabed energy, both from UKSeaMap 2010 (McBreen, et al., 2010). Suitable environmental conditions applied include - low-moderate seabed energy, any sediment type and 10-25 m water depth for current potential. The depth limitations in this instance are based on the industry current reliance on scuba-divers for maintenance and husbandry. It is anticipated that as the industry develops it will become less reliant on divers and be able to move into deeper waters. Note that although the Natural Resource model used the best environmental data available for use in the study but there are significant limitations and gaps. These are outlined below and are discussed in more detail in the final project report: The model does not contain any measure of water quality (e.g. dissolved oxygen, sediment loading or contaminants) and therefore is likely to overestimate the area deemed suitable for aquaculture developments, particularly fin fish cage culture, rope grown bivalve culture and macroalgae culture. The UKSeaMap 2010 predicted seabed sediment map (McBreen, et al., 2010) is modelled at a coarse scale which has led to inaccuracies in the identification of areas which have potential for aquaculture development. UKSeaMap 2010 is known to under-estimate rock habitats because of the type of sampling data (sediment grabs) used to underpin the model. The MMO is working with JNCC to develop these data to lead to improvements in future models. The UKSeaMap 2010 combined seabed energy map included in the model (McBreen, et al., 2010) provides an approximation of the environmental conditions that are likely to limit aquaculture development (e.g. strong currents and large waves) but more accurate results could be obtained by using more precise component datasets such as the maximum wave height and tidal current range, where these datasets are available and the precise limitations of the aquaculture activities of interest are known. The dataset shows potential based on current technologies as defined in Table 10 of the MMO1040 Aquaculture Potential Final Report which is published on the MMO website's evidence pages. ------------------------------------------------------------------------------------------------------------The Bivalve Classification dataset classifies where the production of shellfish can be commercially harvested. All areas listed are designated for species that may be harvested as well as the classification of the shellfish waters. Classification of harvesting areas is required and implemented directly in England and Wales under European Regulation 854/2004. The co-ordination of the shellfish harvesting area classification monitoring programme in England and Wales is carried out by the Centre for Environment, Fisheries and Aquaculture Science, Weymouth (Cefas) on behalf of the Food Standards Agency (FSA). Cefas will make recommendations on classification according to an agreed protocol with the FSA making all final classification decisions and setting out the overall policy. Shellfish production areas are classified according to the extent to which shellfish sampled from the area are contaminated with E. coli. The Classification Zones/Production areas delineate areas where shellfish may be commercially harvested. Coordinates for the zone boundaries are calculated during a sanitary (ground) survey of the production area and where appropriate they are based on the OS Mastermap Mean High Water Line (coordinate accuracy <10m). The maps/zones are correct at time of publication but are updated when necessary depending on hygiene testing results. The current maps (jpgs) are available from the Cefas website ( https://www.cefas.co.uk/publications-data/food-safety/classification-and-microbiological-monitoring/england-and-wales-classification-and-monitoring/classification-zone-maps ) or a listing is available from the FSA website ( http://www.food.gov.uk/enforcement/monitoring/shellfish/shellharvestareas ) ------------------------------------------------------------------------------------------------------------The Current Aquaculture Potential layer highlights areas identified through GIS modelling of suitable environmental conditions in the South and East Marine Plan Areas favourable for macroalgae culture, Bivalve Bottom Culture, Finfish Cage, Lobster Restocking, Rope Cultured Bivalve Shellfish or Trestle/Bag Culture of Bivalves in the South and East Coast Marine Plan Areas. This dataset forms part of a wider study assessing different aquaculture potential in the South and East Marine Plan Areas for the Marine Management Organisation, project MMO1040. This dataset was created using the Natural Resource model which forms part of the MMO project 1040 Spatial Trends in Aquaculture Potential in the South and East Coast Inshore and Offshore Marine Plan Areas. The Natural Resource model is made up of three existing environmental datasets: bathymetry derived from the Department of Food and Rural Affairs (Defra) Digital Elevation Model (DEM), predicted seabed sediments and combined seabed energy, both from UKSeaMap 2010 (McBreen, et al., 2010). Suitable environmental conditions applied include - low-moderate seabed energy, any sediment type, 10-25 m water depth for current potential and 25-50 m water depth for near future potential). The depth limitations in this instance are based on the industry current reliance on scuba-divers for maintenance and husbandry. It is anticipated that as the industry develops it will become less reliant on divers and be able to move into deeper waters. Note that although the Natural Resource model used the best environmental data available for use in the study, there are significant limitations and gaps. These are outlined below and are discussed in more detail in the final project report: The Natural Resource model does not contain any measure of water quality (e.g. dissolved oxygen, sediment loading or contaminants) and therefore is likely to overestimate the area deemed suitable for aquaculture developments, particularly fin fish cage culture, rope grown bivalve culture and macroalgae culture. The UKSeaMap 2010 predicted seabed sediment map (McBreen, et al., 2010) is modelled at a coarse scale which has led to inaccuracies in the identification of areas which have potential for aquaculture development. UKSeaMap 2010 is known to under-estimate rock habitats because of the type of sampling data (sediment grabs) used to underpin the model. It is recommended that this component of the model is supplemented or replaced by higher resolution sediment maps where they are available for the region of interest. The UKSeaMap 2010 combined seabed energy map included in the model (McBreen, et al., 2010) provides an approximation of the environmental conditions that are likely to limit aquaculture development (e.g. strong currents and large waves) but more accurate results could be obtained by using more precise component datasets such as the maximum wave height and tidal current range, where these datasets are available and the precise limitations of the aquaculture activities of interest are known. The potential for development for the feature is "Current" (0-5 years), "Near Future" (5-10 years) or "Future" (10-20 years), the definitions of which are presented in Table 13 within the main report.

Multibeam sonar data obtained from The United Kingdom Hydrography Office (UKHO) and ground-truthing information gathered from field surveys were used to train models and produce predictive habitat maps of kelp distribution along ~19 km stretch of coastline in Southern England. Bathymetric derivatives (roughness and fractal dimension) were used alongside acoustic backscatter intensity and depth as environmental variables for predictive modelling using a generalised boosting model (GBM).

A coastline of Kalaallit Nunaat/ Greenland covering all land and islands, produced in 2017 for the BAS map ''Greenland and the European Arctic''. The dataset was produced by extracting the land mask from the Greenland BedMachine dataset and manually editing anomalous data. Some missing islands were added and glacier fronts were updated using 2017 satellite imagery. The dataset can be used for cartography, analysis and as a mask, amongst other uses. At very large scales, the data will appear angular due to the nature of being extracted from a raster with 150 m cell size, but the dataset should be suitable for use at most scales and can be edited by the user to exclude very small islands if required. The projection of the dataset is WGS 84 NSIDC Sea Ice Polar Stereographic North, EPSG 3413. The dataset does not promise to cover every island and coastlines were digitised using the data creator''s interpretation of the landforms from the images.

This geophysical survey was carried out under contract for the Marine Aggregate Levy Sustainability Fund (MALSF) as part of a Regional Environmental Characterisation, the survey took place from the 8th March to the 18th March 2010. This project is to extend the mapped coverage of the Eastern English Channel Marine Habitat Map (EECMHM) to include the coastal platform from Saltdean east to Dungeness and provide an integrated map dataset covering this extension area The geophysical data was acquired using Surface Tow Boomer and Sidescan sonar equipment. Technical detail of the survey are contained in BGS Open Report OR/10/052.

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.

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.