The General Bathymetric Chart of the Oceans (GEBCO) is a publicly available
bathymetric chart
A bathymetric chart is a type of isarithmic map that depicts the submerged topography and physiographic features of ocean and sea bottoms. Their primary purpose is to provide detailed depth contours of ocean topography as well as provide the size, ...
of the world's
ocean
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...
s. The project was conceived with the aim of preparing a global series of charts showing the general shape of the seafloor. Over the years it has become a reference map of the bathymetry of the world’s oceans for scientists and others.
Organisation
GEBCO operates under the joint auspices of the
International Hydrographic Organization
The International Hydrographic Organization (IHO) is an intergovernmental organisation representing hydrography. , the IHO comprised 98 Member States.
A principal aim of the IHO is to ensure that the world's seas, oceans and navigable waters a ...
(IHO). and the
Intergovernmental Oceanographic Commission The Intergovernmental Oceanographic Commission of UNESCO (IOC/UNESCO) was established by resolution 2.31 adopted by the General Conference of UNESCO. It first met in Paris at Unesco Headquarters from 19 to 27 October 1961. Initially, 40 States becam ...
(IOC) of
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...
. Its work is done by an international group of experts in seafloor mapping who develop a range of bathymetric data sets and data products.
Data sets and products
Although originally GEBCO published paper
contour charts, today it has moved into the digital age and collects digital depths of the ocean from wherever they are available. GEBCO provides a range of bathymetric data sets and data products, including:
*Global gridded bathymetric data sets:
**GEBCO_08 Grid — a global bathymetric grid with 30 arc-second spacing, generated by combining quality-controlled ship depth soundings with interpolation between sounding points guided by satellite-derived gravity data.
**GEBCO_2014 Grid — an update to the previously released GEBCO_08 Grid.
**GEBCO_2019 Grid — an update to the previously released GEBCO_2014 Grid with 15 arc-second resolution.
**GEBCO One Minute Grid — a global grid at one arc-minute intervals, based largely on the most recent set of bathymetric contours contained within the GEBCO Digital Atlas.
The grids are available to download from the
British Oceanographic Data Centre
The British Oceanographic Data Centre (BODC) is a national facility for looking after and distributing data about the marine environment. BODC is the designated marine science data centre for the United Kingdom and part of the National Ocean ...
(BODC) in the form of netCDF files, along with free software for displaying and accessing data in ASCII and netCDF. The grids can be used with the Generic Mapping Tools (GMT) system.
*The GEBCO Digital Atlas — a two volume CDROM set which contains:
**The GEBCO One Minute Grid
**A global set of digital bathymetric contours and coastlines
**The GEBCO Gazetteer of Undersea Feature Names: a digital gazetteer of undersea feature names.
**A software interface for viewing and accessing the data sets
*The GEBCO Gazetteer of Undersea Feature Names — a digital gazetteer of undersea feature names used on sheets and products of GEBCO and Regional International Bathymetric Charts (IBC) projects, and on international (INT) nautical charts. It is available to be downloaded from the International Hydrographic Organization (IHO).
*The GEBCO world map — a global, coloured, paper map of the bathymetry of the world's oceans based upon the GEBCO One Minute Grid. The map is available to be downloaded in the form of
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
file.
Project history
The GEBCO chart series was initiated in 1903 by an international group of
geographer
A geographer is a physical scientist, social scientist or humanist whose area of study is geography, the study of Earth's natural environment and human society, including how society and nature interacts. The Greek prefix "geo" means "earth" a ...
s and oceanographers, under the leadership of
Prince Albert I of Monaco
Albert I (Albert Honoré Charles Grimaldi; 13 November 1848 – 26 June 1922) was Prince of Monaco from 10 September 1889 until his death. He devoted much of his life to oceanography, exploration and science. Alongside his expeditions, Albert I ...
. At that time there was an explosion of interest in the study of the natural world and this group recognized the importance of a set of maps describing the shape of the ocean floor. The first hundred years of the project were described in the book ''The History of GEBCO 1903-2003'' published by GITC in 2003. Nowadays GEBCO’s role has become increasingly important, due to the increased interest in the oceans for scientific research and for the exploitation and conservation of resources.
Since 1903, five separate editions of paper, bathymetric contour charts covering the whole world have been produced. GEBCO is now maintained in digital form as the GEBCO Digital Atlas.
Training
The
Nippon Foundation
of Tokyo, Japan, is a private, non-profit grant-making organization. It was established in 1962 by Ryoichi Sasakawa. The foundation's mission is to direct Japanese motorboat racing revenue into philanthropic activities, it uses this money t ...
of Japan has provided funding for GEBCO to train a new generation of scientists and hydrographers in ocean bathymetry. The 12-month course, leading to a Postgraduate Certificate in Ocean Bathymetry (PCOB), has been held at the
University of New Hampshire
The University of New Hampshire (UNH) is a public land-grant research university with its main campus in Durham, New Hampshire. It was founded and incorporated in 1866 as a land grant college in Hanover in connection with Dartmouth College, mo ...
, USA, since 2004. 60 GEBCO scholars from 31 different countries have completed the course and are supporting GEBCO programs.
Seabed 2030 Project
The Nippon Foundation-GEBCO Seabed 2030 Project, which aims to motivate a number of collaborators to create a full map of the ocean floor, was launched in 2016.
There are four Seabed 2030 centres, which coordinate mapping activities in different regions, gather and compile the bathymetric information, and partner with existing mapping activities within their regions. The Seabed 2030 Global Center is responsible for "producing and delivering global GEBCO products".
GEBCO is the only intergovernmental body with a mandate to map the whole ocean floor. At the beginning of the project, only 6 per cent of the world's ocean bottom had been surveyed to today's standards; , the project had recorded 23.4 per cent mapped. About of new bathymetric data was included in the GEBCO grid in 2019, and an additional area equivalent to the size of Europe between 2020 and 2022. Satellite technology, using
altimeter
An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. The m ...
s that infer seafloor topography from the way its gravity affects the surface of the ocean above it, but it does not give a sufficiently high resolution. Seabed 2030 initially aimed at using a global 100m grid, but this has been updated to use a variable resolution grid, with larger squares over deep ocean floor and smaller ones in shallow waters.
[
Governments, institutions and companies have been contributing to the effort, and Seabed 2030 is ]crowdsourcing
Crowdsourcing involves a large group of dispersed participants contributing or producing goods or services—including ideas, votes, micro-tasks, and finances—for payment or as volunteers. Contemporary crowdsourcing often involves digita ...
information from any party that is able to contribute, including small boats. The British Antarctic Survey
The British Antarctic Survey (BAS) is the United Kingdom's national polar research institute. It has a dual purpose, to conduct polar science, enabling better understanding of global issues, and to provide an active presence in the Antarctic on ...
is assisting the effort by varying the routes of its boats in order to map different parts of the sea floor.[
]
References
External links
*
GEBCO Digital Atlas
GEBCO's gridded data sets
GEBCO – Maps of world ocean bathymetry
* ttps://web.archive.org/web/20110811145922/http://apomabdoc.altervista.org/index.html The Academy Of Positioning Marine And Bathymetry (APOMAB)– an independent, no-profit, no-governmental website. It provides a forum for all those involved in activities related to the disciplines of marine positioning and bathymetry members who live or work anywhere in the world.
GEBCO-OUTREACH
is a website for diverse usage of GEBCO product for education purposes and other outreach activities such as posters and presentation materials.
{{DEFAULTSORT:General Bathymetric Chart Of The Oceans
Oceanography
World maps
Hydrography