Data covering the marine environment, including fisheries, coral reef  health, ocean chemistry, and coastal zones.

oceans-seas-coasts

Oceans, Seas, & Coasts

### Overview  
  
The Bathymetry dataset is composed of the GEBCO_2019 Grid, which shows terrain elevation around the world, for both land and the ocean floor. It provides global coverage on a 15 arc-second grid. The data values refer to elevations at the center of grid cells in meters.

  
  
The GEBCO_2019 Grid is the latest global bathymetric product released by the General Bathymetric Chart of the Oceans (GEBCO) and has been developed through the Nippon Foundation-GEBCO [Seabed 2030 Project](https://seabed2030.gebco.net/). This is a collaborative project between the Nippon Foundation of Japan and GEBCO. The Seabed 2030 Project aims to bring together all available bathymetric data to produce the definitive map of the world ocean floor and make it available to all.  
  
### Methodology  
  
The grid used Version 1 of the Shuttle Radar Topography Mission (SRTM) 15+ data set as a ‘base’. This dataset is a fusion of land topography with measured and estimated seafloor topography. It is largely based on version 11 of SRTM30+, augmented with the gridded bathymetric data sets developed by the four Seabed 2030 Regional Centers.

  
  
The Regional Centers compiled gridded bathymetric data sets for their areas of responsibility. These regional grids were then provided to the Global Center. For areas outside of the polar regions, these data sets are in the form of 'sparse grids,' meaning only grid cells that contain data were populated. For the polar regions, complete grids were provided due to the complexities of incorporating data held in polar coordinates.

  
  
The majority of the work, for the non-polar regions, was done using the 'remove-restore' procedure. This is a two stage process of computing the difference between the new data sets created by regional centers and the 'base' grid SRTM15+. The difference between the datasets was gridded and then added back to the existing 'base' grid. The aim was to achieve a smooth transition between the 'new' and 'base' data sets with minimum disturbance of the existing base data set. The polar and Red Sea datasets were supplied in the form of complete grids and were created using feather blending techniques from GlobalMapper software version 11.0.
  
  
The compilation of the GEBCO_2019 Grid from these regional data grids, with some additional source data sets, was carried out at the Global Center, with the aim of producing a seamless global terrain model. The global grid consists of 86,400 rows and 43,200 columns, giving 3,732,480,000 data points. 

  
  
For the full documentation, please click on the “Learn more” button.
  
  
### Additional Information  
  
Resource Watch shows only a subset of the dataset. Additional data for the Type Identifier Grid (TID) is available from the data provider. The TID identifies the type of source data that the corresponding grid cells in the GEBCO Grid are based on.  For access to the full dataset and additional information, click on the “Learn more” button.  
  
### Visualizing the Data  
  
Our team reformatted this dataset before displaying it on Resource Watch. See the documentation on how Resource Watch processed the data on [Github](https://github.com/resource-watch/data-pre-processing/blob/master/ocn_001_gebco_bathymetry/).  
  
### Disclaimer  
  
Excerpts of this description page were taken from the source metadata.

Ocean Watch

Bathymetry

Bathymetry (kilometers)