Bathymetry

Understanding the topography of the European seas

Bathymetry Viewing and Download service

User Help

This Bathymetry Viewing and Download service provides various ways for browsing and interacting with the EMODnet Digital Terrain Model (DTM) and associated metadata by means of information map layers and specific functions per active layer. It also features a number of additional map layers with information which is relevant for the bathymetry domain. It is assumed that the user has a basic familiarity with geo-spatial tools and terminology.

The 2018 version of the EMODnet digital terrain model (DTM) itself has been created at a grid resolution of 1/16 * 1/16 arc-minutes (circa 115 * 115 meter) using the best available bathymetry data sets from an increasing number of data providers. In practice more than 9400 data sets have been included from plummets, single beam, multi beam, and LIDAR observations, from composite DTMs and Satellite Derived Bathymetry for selected coastal stretches. Despite this there are still areas where high quality bathymetry data is not available or could not be obtained. To prevent gaps in the EMODnet DTM layer, these areas have been filled with the GEBCO 2014 data. However the search for additional data continues and extra data providers are invited to share their data using the EMODnet Ingestion facility.

Disclaimer:

Although the bathymetry available is based on the best available bathymetry and every effort is made with respect to the quality assurance and quality control, it should be noted that, accuracy, completeness, reliability, usability or suitability of the bathymetry cannot be guaranteed. Therefore the data products available from this service are not to be used for navigation or for any other purpose relating to safety at sea. EMODnet assumes no responsibility for incorrect results or damages resulting from the use of the data.

Browser support is given from Firefox 35, Chrome 40, IE 11, all under Windows 7, Windows 8 and Windows 10, and Safari 7.1, Firefox 35, Chrome 40 under OS X. Older browsers might experience problems due to the used technologies.

Table of Contents

What the Bathymetry Viewing and Download service provides

This service provides bathymetric data products for the European sea regions in an area specified by the EMODnet project. This covers the European arctic waters, Barentsz Sea, Norwegian Sea, Icelandic waters, Celtic Seas, Western Approaches, North Sea, Kattegat, Baltic Sea, English Channel, Bay of Biscay, Iberian Coast, West and Central Mediterranean, Adriatic Sea, Ionian Sea, Aegean Sea, Levantine Sea, Sea of Marmara, Black Sea, the Azores, Canary Islands and Madeira. The data product is provided in one sixteenth arc minute grid, so data points are roughly 115 meters apart.

The bathymetric data product can be downloaded in different formats. Currently the following formats are supported: native EMODnet csv, ASCII xyz, Esri ASCII grid, EMODnet NetCDF, GeoTIFF and QPS SD (Fledermaus). The EMODnet csv file is available with and without GEBCO and interpolated (INT) values. The download is divided over tiles. Apart from downloading bathymetric data products the service provides information regarding point depth, transects and metadata of the underlying surveys. The EMODnet bathymetric data product is based on survey data and composite digital terrain models of hydrographic organizations and research institutes and Satellite Derived Bathymetry data products for selected coastal stretches (a complete overview of the contributing organizations and partners can be found at the EMODnet bathymetry website). The survey data itself are not directly available but the related EMODnet Bathymetry CDI Data Discovery and Access service provides facilities for identifying and requesting access to survey data sets. The used composite DTMs are described in the Sextant Catalogue Service.

There are areas that are not covered by surveys, composite DTM's or SDB. These areas have been filled with data available from GEBCO 2014.

The Bathymetry Viewing and Download service also provides a source references layer with metadata for the detailed survey data and composite DTM"s as used for the EMODnet bathymetry data product.

Bathymetry viewing and download service interface


Using the service

Using the service will address the layer panel, adding a layer yourself and using the available tools in the user interface.

Use interface layout

The service provides essentially a bathymetric map. There are several layers and these layers, when activated, can have specific functions which are displayed in the top bar by buttons.

Layers panel

The layers panel is the main control for choosing what kind of information you would like to examine. Although many layers can be made visible at the same time, only one layer can be active. The active layer determines the behaviour and corresponding functionality. The layer list can be selected by clicking on the down arrow of the left selection list in the function bar. Every layer has the following properties:

Layers panel

Adding a layer

In addition to the available layers you can add layers yourself. Click on Add layer to initiate the process of adding a WMS layer. Complete the following steps:

Make sure the added layer is based on WGS84. WMS Layers based on projections are not supported.

Using the general tools

The following tools are available:

Then depending on the active layer additional tools and functions will be available. These tools and functions will be explained below in the context of specific layers.

Continuing from the last session

If your browser supports HTML5 storage the user defined WMS layer(s) and predefined WMS layer settings as well as the zoom level and pan position are stored. When starting a new session the portal will be initialized with these settings. When a browser option like clearing session data when closing a tab or browser is active, the session settings are lost.


Using the Data product

The Bathymetric data product

The EMODnet data products are based on the continuous average depth grid of one sixteenth arc-minute. This grid is based on three source types: Individual bathymetric surveys, composite digital terrain data (cDTM) and Satellite Derived Bathymetry. The latter two have been used whenever the actual survey data was unavailable for direct processing by the EMODnet partners. Whenever data were unavailable GEBCO data has been used to fill in the gaps.

Different layers of bathymetric data are available:

The following information can be retrieved from the active depth layers by additional function buttons:


The Source references layer

This layer depicts the most significant elementary surface used for generating the grid cell value. The minimum resolution for this layer is 5 EMODnet grid cells in order to prevent too much detail in this layer. For every 5 EMODnet grid cells the most significant elementary surface has been determined. All neighbouring source reference "points" with the same reference are represented by a single polygon. Every polygon has its own fill colour. All polygons referencing the same source have the same fill colour. Be aware that one colour is not referencing the same unique source, since this would require more than 6.000 different colours. The only exception is that a grey fill colour always references a GEBCO source.

Source reference


The Survey tracks / polygons layer

This layer is provided as WMS by the EMODnet Bathymetry CDI Data Discovery and Access service. It shows all survey tracks and polygons for which survey data is available in the service, and not only those that have been used for the EMODnet Bathymetry data product. Also this has a global coverage.

Survey tracks


Download products

Download products tool

The Download products button is always visible and allows you to select and download EMODnet Bathymetry DTM tiles in various formats. The function includes downloading the 2016 version of the EMODnet DTM (1/8 * 1/8 arc minutes resolution) in 16 tiles or the 2018 version (1/16 * 1/16 arc minutes) in 64 tiles. Clicking on the button and choosing the version (2016 / 2018) will display a grid of 16 / 64 tiles over the EMODnet Bathymetry area.

Select DTM version

If you want to request tiles from the grid in the map, simply click on the tiles you are interested in:

Select DTM tiles

The tiles you selected are listed in the right hand panel and you are able to remove a tile if you wish:

Listed products

You must also select a format

Select a product format

The file types have the following specifications:

After selecting a file format you can request for a product download

Download selection

Clicking this button will open an order form. You can order using your Marine ID if you already have one or by just filling in your details. A correct email address is important as you will receive a message with a download link via which you can retrieve the selected data. It is advised to register for Marine ID if you will return to the downloading service multiple times as it will save you from entering your details multiple times. 'Authenticate via Marine ID' allows you to logon or to register for Marine ID.

The downloading of tiles is free and without restrictions. However the lightweight registration of your details and reason for downloading has been added allowing us to learn better our users and their applications. This will support the planning of future upgrades.

Download registrations

If your submit was complete and correct you should see the following message:

Completed download

Subsequently (this might take a few minutes to hours depending on your order) you will receive an email with subject: Your EMODnet Bathymetry download is ready

Download confirmation email

Please note that the links in the message are active for 12 hrs and will be deleted thereafter.


Coastal areas with High Resolution bathymetry

This layer has been added in September 2015 to test the concept of a multi resolution product. High resolution data is available for the German North Sea coast, the French Mediterranean coast and Dunmanus bay in Ireland. Activating the layer will highlight these areas and the user is facilitated to zoom in further than in the overall bathymetry layers.


Additional layers

Several other layers are provided that are relevant for the bathymetry domain. These include:


3D visualization functionality

3D visualization functionality has been added to the bathymetry viewing that can be used in the browser without requirement of plugins. The 3D application is based on Cesium. However a dedicated data structure has been developed by EMODnet Bathymetry based on a triangulated irregular network (TIN). Having a TIN instead of a regular grid enables faster representation of the complexity of the map (i.e. the number and size of triangles). Software has been developed to create tiles in quantized mesh format out of a raster format such as used in EMODnet DTM. Later this software will be documented and made available at GitHub and promoted at the EMODnet Bathymetry portal.

3D visualization functionality

Click on the '3D' button on the bathymetry map for activating the 3D visualization functionality. The service works with the mouse as follows:

Note: The 3D service has been set to a distortion of horizontal : vertical of 1:6. The service is still in Beta and instabilities might occur, in particular when moving to fast and diving under the water surface.

OGC WMS, WMTS, WFS and WCS services

The GIS layers in the Bathymetry Viewing and Download service can be shared as OGC services with other EMODnet portals and beyond. Also WMS layers from other EMODnet portals and external services can be added to the Bathymetry Viewer and Download service. The OGC services can be found at the following URLs:

WMS:https://ows.emodnet-bathymetry.eu/wms
WMTS:https://tiles.emodnet-bathymetry.eu/
WFS:https://ows.emodnet-bathymetry.eu/wfs
WCS:https://ows.emodnet-bathymetry.eu/wcs

More detailed information on these webservices can be found at the following page.

Colophon

In addition to the data and products of EMODnet bathymetry partners use is made of the following sources:


Questions & Feedback

For questions and feedback please use the Feedback button of the portal. We would really like to know your findings and ideas on how the portal could be improved.


Configuration information

This help text is version 4.0 and released on 14 September 2018.

The Bathymetry Viewing and Download service is built and maintained by GGSgc and partners coordinated by MARIS and on behalf of the European Commission.