General Bathymetric Chart of the Oceans (GEBCO)

GDA development

The GEBCO chart series was initiated in 1903. Five separate paper editions have been produced showing global coverage of bathymetric contour data. Today, GEBCO is maintained at BODC in the form of a digital atlas - the GEBCO Digital Atlas (GDA).

GDA initialisation

The GDA was first published in 1994. The bathymetric contours, coastlines and ship trackline data digitised from the 5th Edition GEBCO chart series (sheets 5.01 to 5.18) were used to initialise the GDA. This created a digital base for the future updating of GEBCO and provides a more flexible product for users. An updated version of the GDA was released in 1997.

The Centenary Edition of the GDA

In April 2003, the Centenary Edition of the GDA, was published. This edition includes new bathymetric compilations for  the Arctic Ocean, the Indian Ocean, the northeast and central-eastern Atlantic, the Caribbean Sea and the Gulf of Mexico, the Weddell Sea and the waters around New Zealand (sheets G.01 to G.08).

An updated version of the GDA was released in July 2009 on DVD to include both the GEBCO One Minute and GEBCO_08 Grids.

The geographic coverage of the sheet areas digitised to form the Centenary Edition of the GDA is shown below. Update sheets G.01 to G.09 were compiled primarily at scales of the order of 1:1 million. Areas numbered 5.01 to 5.18 are based on the GEBCO 5th Edition chart series. However, 5th Edition sheets 5.09, 5.13 and 5.17 have been completely replaced.

Click on a chart number to find out more about the source data set.

Chart areas for the Centenary Edition of the GDA
Chart areas for the Centenary Edition of the GDA ©
G.01 5.01 5.02 5.03 5.04 G.02 IBCM 5.05 5.06 5.07 5.08 G.04 IBCM G.03 G.05 G.06 G.08 G.08 5.10 5.11 5.12 G.09 5.14 5.15 5.16 G.07 5.18

The GDA includes the GEBCO One Minute Grid, providing bathymetry data on a one minute interval global grid. It is based largely on the bathymetric contours contained within the GDA. Additional control contours and sounding data were used in many regions, particularly shallow water areas and semi-enclosed seas, to constrain the gridding processes. It includes land elevations derived from the Global Land One-km Base Elevation (GLOBE) data set. Information on the development of the GEBCO One Minute Grid can be found here. Adobe PDF version of the Guide to the GEBCO One Minute Grid (791 KB)

In January 2009 GEBCO released the GEBCO_08 Grid providing bathymetry data on a global 30 arc-second interval grid. The grid was largely generated by combining quality-controlled ship depth soundings with interpolation between sounding points guided by satellite derived gravity data. Since its initial release the grid has been updated in November 2009 and September 2010.

GEBCO's latest global 30 arc-second bathymetric grid is the GEBCO_2014 Grid released in November 2014.

Both gridded data sets can be downloaded from the web and are included on the GDA DVD.

The GDA also contains a global set of digital bathymetric contours, coastlines and trackline control data and a software interface. Find out more about the contents of the GDA and the features of the GDA software interface.

Find out more about the GDA and its data sets from the GDA manual. Adobe PDF version of the GEBCO Digital Atlas manual (2009 KB)

Bathymetric compilations included in the Centenary Edition of the GDA

G.01 Arctic Ocean

The contours for this region were compiled in 2001 from the gridded data set of the International Bathymetric Chart of the Arctic Ocean (IBCAO). The data set covers the area 64°N to 90°N, 180°W to 180°E. The contours were prepared for GEBCO by Norman Cherkis and Martin Jakobsson.

The GEBCO One Minute Grid is based on the IBCAO gridded data set in this region.

Contours present

The data set contains bathymetric contours at a depth of 20 m, 50 m, 100 m, 150 m, 200 m, 300 m, 400 m, 500 m and at 500 m intervals thereafter down to 5500 m. Additional contours at 100 m intervals from 500 m to 3400 m are also present in southern boundary region between 95°W and 5°E.

Find out more about the compilation of the bathymetric contours for sheet G.01. Adobe PDF version of the documentation for GEBCO data set G.01 (20 KB)

G.02 Northeast Atlantic off the British Isles

This data set was compiled in February 1997 and originally published in the 1997 release of the GEBCO Digital Atlas. The bathymetric contours were compiled and digitised at scales from 1:1 million to 1:250,000 in certain areas. The data set covers the area 47°N to 64°N, 37°W to 6°E and was assembled by Peter Hunter of the National Oceanography Centre, Southampton (formerly Southampton Oceanography Centre), UK.

Contours present

100 m intervals throughout the area down to a maximum contour depth of 5000 m. Contours at 50 m intervals are present on Rockall Bank.

Find out more about the compilation of the bathymetric contours for sheet G.02. Adobe PDF version of the documentation for GEBCO data set G.02 (54 KB)

G.03 Caribbean Sea and the Gulf of Mexico

The bathymetric contours for this region are taken from the International Bathymetric Chart of the Caribbean Sea and the Gulf of Mexico (IBCCA), sheets 1.04 to 1.09.

The bathymetric charts were compiled between 1997 and 2001.

The contours were compiled and digitised at a scale of 1:500,000. The data set covers the area 5°N to 33°N, 101°W to 69°W (and to 61°W from 15°N to 24°N).

Contours present

Standard contours at depths of 20 m, 40 m, 60 m, 80 m, 100 m, 200 m, and at 200 m intervals thereafter down to 8400 m. Also included as standard are contours at 500 m and at 1000 m intervals thereafter. Intermediate contours appear frequently on the sheets so many areas include contours at 100 m intervals, and some areas include more frequent shallow water contours up to 200 m. Some of the abyssal floor areas also have contours at 10 m and 20 m intervals.

Find out more about the compilation of the bathymetric contours for sheet G.03. Adobe PDF version of the documentation for GEBCO data set G.03 (58 KB)

G.04 Northeast Atlantic off the Iberian Peninsula

This data set consists of three compilations

The geographic limits of the data set are 31°N to 48°N, 18°W to 0°W — see the above index chart for the actual geographic coverage of the data set.

Contours present

The Bay of Biscay region and IBCEA Sheet 1.01 contain contours at 200 m intervals. Also included in the digital data, but not on the published charts, are contours at a depth of 500 m and at 1000 m intervals thereafter. IBCEA Sheet 1.01 also includes contours at depths of 50 m, 100 m and 150 m.

The Strait of Gibraltar and Maderia region contain contours at a depth of 20 m, 50 m, 100 m and at 100 m intervals thereafter. Additional intermediate contours may be found in abyssal areas.

Find out more about the compilation of the bathymetric contours for sheet G.04. Adobe PDF version of the documentation for GEBCO data set G.04 (25 KB)

G.05 Mid Atlantic Ridge to Northwest Africa

The bathymetric contour data for this area were compiled for GEBCO in 2002 by Peter Hunter of the National Oceanography Centre, Southampton (formerly Southampton Oceanography Centre), UK, and include data from the International Bathymetric Chart of the Central Eastern Atlantic (IBCEA) sheet 1.06 published by the Service Hydrographique et Oceanographique de la Marine (SHOM), France, in 2000. The bathymetric contours were compiled and digitised at a range of scales from 1:250,000 to 1:1,250,000.

The geographic limits of the data set are 18°N to 35°N, 47°W  to 14°W — see the above index chart for the actual geographic coverage of the data set.

Contours present

The area of the sheet from the 4600 m contour westwards to 30°W is contoured at 100 m intervals. West of about 30°W, the bathymetry is contoured at 500 m intervals. The area of IBCEA sheet 1.06 has contours at a depth of 50 m, 100 m, 200 m and at 200 m intervals thereafter, including intermediate 500 m interval contours.

Find out more about the compilation of the bathymetric contours for sheet G.05. Adobe PDF version of the documentation for GEBCO data set G.05 (22 KB)

G.06 Central Eastern Atlantic

The bathymetric contours for this region are taken from the International Bathymetric Chart of the Central Eastern Atlantic (IBCEA) sheets 1.08 to 1.12 published by the Service Hydrographique et Oceanographique de la Marine (SHOM), France, between 1999 and 2001. The contours were compiled and digitised at a scale of 1: 250,000.

Contours present

The data set contains bathymetric contours at a depth of 50 m, 100 m, 200 m and at 200 m intervals thereafter down to a maximum contour depth of 7800 m. Also included in the digital data, but not on the printed sheets, are contours at a depth of 500 m and at 1000 m intervals thereafter.

Find out more about the compilation of the bathymetric contours for sheet G.06. Adobe PDF version of the documentation for GEBCO data set G.06 (35 KB)

G.07 Weddell Sea and the Bransfield Strait

Bathymetric contour data for this region were provided to GEBCO by Hans-Werner Schenke and co-workers at the Alfred Wegener Institute (AWI), Germany. They include contributions from Gleb Udintsev and colleagues from the Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russia. The bathymetric contours were compiled and digitised on Mercator sheets at a variety of scales between 1:250,000 and 1:1 million. A subset of this data set was included in the 1997 release of the GEBCO Digital Atlas.

The geographic limits of the data set are 60°S to 79°S, 75°W to 2°E — see the above index chart for the actual coverage of the data set.

Contours present

The data set contains contours at a depth of 100 m and at 100 m intervals thereafter down to 7200 m.

Find out more about the compilation of the bathymetric contours for sheet G.07. Adobe PDF version of the documentation for GEBCO data set G.07 (30 KB)

G.08 Greater Indian Ocean

The bathymetric contours in this region were compiled by Dr R.L. Fisher of Scripps Institution of Oceanography, USA. The contours were compiled on some 250 sheets at a scale of 4 inches per degree of longitude (approximately 1:1 million) over a ten year period up to 2002. The geographic limits of the data set are 31°N to 72°S, 12°W to 170°E — see the above index chart for the actual geographic coverage of the data set. A subset of the full data set was published in the 1997 version of the GDA.

Contours present

The data set contains contours at a depth of 200 m, 500 m and at 500 m intervals thereafter down to 7000 m. In some areas the 100 m contour is also present.

Find out more about the compilation of the bathymetric contours for sheet G.08. Adobe PDF version of the documentation for GEBCO data set G.08 (27 KB)

G.09 Waters around New Zealand

The bathymetric contour data for this area were contributed by Ian Wright of the National Institute of Water and Atmospheric Research (NIWA), Wellington, New Zealand. The data were compiled and digitised from charts at a scale of 1: 1 million. The chart was published in 1997.

The geographic limits of the data set are 24°S to 57°30’S, 157°E to 167°W — see the above index chart for the actual geographic coverage of the data set.

Contours present

The data set contains contours at a depth of 50 m, 100 m, 150 m, 200 m, 250 m and at 250 m intervals thereafter down to 10,000 m.

Find out more about the compilation of the bathymetric contours for sheet G.09. Adobe PDF version of the documentation for GEBCO data set G.09 (14 KB)

International Bathymetric Chart of the Mediterranean (IBCM)

The IBCM consists of ten sheets on Mercator projection at a scale of 1:1 million (at 38°N) and covers an area 30°N to 46°N, 6°W to 36° 30'E. The Black Sea is included at a scale of 1:2 million for the area 40°N to 47° 30'N, 26° 30'E to 42° 30'E. The chart series was published in 1981 by the Head Department of Navigation and Oceanography, St Petersburg, Russia, on behalf of the Intergovernmental Oceanographic Commission (IOC).

Contours present

Most sheets show bathymetric contours at depths of 20 m, 50 m, 100 m, 200 m and at 200 m intervals thereafter. However, the actual contours displayed vary slightly from sheet to sheet.

Find out more about the digitisation of the IBCM chart series. Adobe PDF version of the documentation about the digitisation of the IBCM chart series (14 KB)

GEBCO 5th Edition sheets

The GEBCO 5th Edition chart series consists of 16 sheets on a Mercator projection at a scale of 1:10 million (at the equator) in the region 72°N to 72°S and two polar sheets on a polar stereographic projection at a scale of 1:6 million at 75°. Most of the sheets were published by the Canadian Hydrographic Service between 1978 and 1982. A revised version of 5.12 was published in 1994. A pre-publication copy of this sheet was digitised for inclusion in the first release of the GEBCO Digital Atlas from charts at a scale of 1:5 million.

The bathymetric contours, trackline control and coastline data were digitised from the GEBCO 5th Edition sheets and formed the basis of the first release of the GEBCO Digital Atlas, published in 1994. As new bathymetric compilations have become available, the GDA has been updated. The current release of the GDA includes new bathymetric compilations as described above in sections G.01 to G.09.

Contours present

Bathymetric contours are at standard depths of 200 m, 500 m and then 500 m intervals thereafter. However, on some sheets contours at intermediate depths have been included.

Find out more about the compilation of the bathymetric contours for GEBCO 5th Edition sheets. Adobe PDF version of the documentation for GEBCO 5th Edition sheets (139 KB)


Related GEBCO Digital Atlas pages at BODC

GEBCO Digital Atlas (GDA) introduction      Copyright and attribution
Contents      Order the GEBCO Digital Atlas
Software interface      Data set errata
Sample images Software Interface updates
Data export formats  

Related GEBCO project pages at BODC

GEBCO at BODC      GEBCO Web Map Service (WMS)
Project overview GEBCO Grid display software
GEBCO world map IHO-IOC GEBCO Cook Book
Download data — GEBCO's gridded bathymetric data sets  

Related external links

Official GEBCO web site      International Bathymetric Chart of the
Mediterranean (IBCM)
International Hydrographic Organization
(IH0)
     International Bathymetric Chart of the Caribbean Sea and the Gulf of Mexico (IBCCA)
Intergovernmental Oceanographic
Commission (IOC)
     International Bathymetric Chart of the Arctic Ocean (IBCAO)
International ocean mapping projects      The Global Land One-km Base Elevation (GLOBE) project
International Bathymetric Chart of the Central Eastern Atlantic (IBCEA)