USGS Thesaurus

The USGS Thesaurus is a controlled vocabulary providing category terms for scientific information products generated by the U.S. Geological Survey. It is designed as a formal thesaurus conforming to ANSI/NISO Z39.19, with rigid adherence to the hierarchical (BT, NT) term relationships, generic non-hierarchical (RT) relationships, and lead-in term relationships linking non-preferred terms to descriptors either singly (UF) or in a compound USE- WITH relationship. The thesaurus is faceted, meaning its top terms delineate general aspects of information resources:
Major educational fields, fields of study, and professional groupings within USGS.
Techniques, methods, procedures, or strategies for research, management, collection, or analysis of scientific information in USGS
Themes, subjects, and concerns for which USGS information resources are relevant
Product types
General representation of the information in a resource, such as a map or data set
Time periods
Geologic time periods and seasons of the year
Institutional structures and activities
Activities, processes, and organizational concepts

The thesaurus is limited in depth and specificity of coverage. It does not attempt to replicate existing controlled vocabularies such as AGI's GeoRef. The intention is to provide sufficient contextual cues for the information seeker to determine the relevance of a resource for his or her concern, not to locate precisely the answer to a specific user question.

See also: Keywords in metadata: what to expect from them, what not to expect; how to choose them; how to get the most value from them.

Recent terms added to the USGS Thesaurus


Download Format Size Contents SQLite 8 MB USGS Thesaurus and other public thesauri
USGSThesaurus.rdf RDF-XML 963 kB SKOS for USGS Thesaurus only (lacks Use-With terms)
CommonGeographicAreas.rdf RDF-XML 73 MB SKOS or Common Geographic Areas thesaurus
CMECS.rdf RDF-XML 575 kB SKOS for Coastal and Marine Ecological Classification System
MarinePlanningData.rdf RDF-XML 99 kB SKOS for Data Categories for Marine Planning


Science Topics, a component of the USGS home page from 2005 to 2015, was a browsable index of web resources intended for the public. It augmented traditional search and site-specific browse interfaces in concert with a "USGS by State" and "About USGS" sites, and was specifically intended to work alongside those facilities.

This infrastructure was specifically intended to help people outside USGS find information on USGS web sites without specific knowledge of the organizational structure and operations of the USGS. The interface design was based on the idea that finding information cannot be separated from understanding, so in the process of browsing or searching a user is assisted by seeing relationships among scientific concepts, and learns while searching.

Underpinning this interface were several controlled vocabularies structured as formal thesauri and authority lists, a catalog of web resources appropriate for the intended audience, and software used to create, review, and modify both the controlled vocabularies and the catalog records. The system served as an example of the reapplication of classic library methodologies in the web setting.

Each information resource in the Science Topics catalog was categorized using several index terms. Consequently a document would be listed under each category for which it would be considered a relevant resource. Approximately 2000 web resources were listed in the catalog.

Questions and comments about the thesaurus or the USGS implementation of it can be sent to