Skip to main content

Gazetteer Catalogs Ocean Features

Multinational effort supports a tool to search the contours of the seafloor

Global images showing the tracklines of vessels in the ocean to map underwater features
Courtesy of GEBCO Gazetteer and NOAA NCEI

As ships and ocean observers criss-cross the globe to study undersea terrain, a web directory tracks the growing knowledge of the ocean floor. In an effort at standardization, hydrographers, research institutes, governments, and others from the global maritime community utilize an NCEI-built tool to sort and name newly discovered places in the ocean. 

The GEBCO Undersea Feature Names Gazetteer, hosted online by the International Hydrographic Organization’s Data Center for Digital Bathymetry (IHO DCDB), co-located with NCEI, allows the public to search for, view, and download information about more than 3,800 undersea features. The public can find information including geographic location, feature dimensions, the discoverer, and the origin of the name. The tool simplifies tracking so that if a place has already secured a name or has been christened by a discoverer, duplication in naming is less likely. The Gazetteer also reduces misidentification.

From mud volcanoes to reefs, the Gazetteer uses several criteria for browsing seafloor features throughout the world’s oceans. Users can search for locations with a few dropdown menus and a world map. Dropdown menus filter for feature type (reef, barrier, seamount or more than 100 others), by discoverer, and by feature name, if available. 

Newly identified ocean features, primarily those outside territorial waters, are submitted for naming through the GEBCO Sub-Committee on Undersea Feature Names (SCUFN). The Gazetteer contributes to streamlining the naming process by giving accurate, up-to-date listings that improve the quality of information about the ocean floor.   

Development of the Naming Gazetteer

Almost a decade ago, a multinational group of hydrographers and Earth scientists affiliated with a group dedicated to mapping oceans, under the name General Bathymetric Chart of the Oceans (GEBCO), envisioned a digital Gazetteer. They saw a need to keep up with the growing details about the features below the surface, especially newfound ones beyond territorial boundaries. At first, a paper Gazetteer was produced annually and evolved with NOAA’s support into today’s digital version.

Ships that survey the oceans continue to improve the picture of the seafloor, exacerbating an existing problem of sorting the information. GEBCO members advanced the idea of a digital Gazetteer because newer mapping technologies have vastly improved the resolution of the sea bottom. According to authors of a scientific article about the Gazetteer published in the open access journal Earth & Space Science News, the level of detail is such that “some features only tens of meters in relief are now being mapped and named.”

Technologies, such as multibeam sonar, remotely operated underwater vehicles, and autonomous underwater vehicles, are expanding the knowledge base—and confusion. Previously, informal names used repeatedly over a period of years have been incorporated into maps and scientific papers. One name might also be applied to several different features, or a single feature could be named independently by different groups, resulting in several different informal names. This has led to misidentification and disagreement on occasion.  

Gazetteer Gives Clearer History

History can be found on the Gazetteer. Not all of the 3,800 features are attached to a namesake but may take on the nomenclature of the region or an old nickname that has stuck, such as Wrecks Reef in the Tasman Sea. In some cases, information about a feature’s past may be available in detail

For instance, the Lord Howe Seamount Chain off the Australian coast near the Great Barrier Reef includes several individual features, a few of which are named for people, such as Elizabeth Reef and Gifford Guyot, an undersea mountain with a flat top. The Gazetteer provides information that Gifford Guyot was named for the spouse of Henry W. Menard of the Scripps Institution of Oceanography in La Jolla, California. It was discovered by the U.S. research vessel Horizon in 1952 during the Capricorn Expedition. The guyot also has been called the Gifford Tablemount, a duplication that supports the objective of the Gazetteer—to clear up misidentifications. 

Establishing Naming Authority

Although not the first of its kind, the Gazetteer furthers GEBCO’s aim to provide the most authoritative publicly available bathymetry of the world’s oceans. Several national naming authorities and geographic naming boards also maintain separate gazetteers. The GEBCO Gazetteer endeavors to harmonize the existing data. Along with NCEI, the Gazetteer is supported by the International Hydrographic Organization andIntergovernmental Oceanographic Commission of the United Nations Educational, Scientific and Cultural Organization (UNESCO).

NOAA Hosts the Gazetteer 

NCEI hosts the GEBCO Gazetteer of Undersea Feature Names database and makes the undersea feature names with geographic location on the seafloor and corresponding information available via an interactive web map application developed in 2013. The latest version, released in 2020, includes an innovative new 3D Earth map to display undersea features. The Gazetteer's related GIS services provide map data as KML, WMS, and ArcGIS layers. The Gazetteer provides undersea feature data through a REST API in shapefile, spreadsheet, JSON, and TopoJSON formats. The Gazetteer database is maintained remotely by the GEBCO SCUFN.

Related News