The American Geosciences Institute (AGI) compiles the information in GeoRef according to broad subject categories. For example, the AGI description for the geosciences literature in the Environmental Geology subject category is:
"climate change, ecology, geologic hazards-earthquakes, floods, land subsidence, landslides, debris flows, tsunamis, volcanoes, groundwater pollution conservation, land use, pollution of surface water (seldom covered) reclamation"
This practice of organizing the geosciences literature is very helpful to researchers when they want to focus their search for literature in only the subject categories that they are most interested in.
To limit your search in GeoRef to a major subject category you must first determine the exact name of the subject category. To do that use the indexes lookup feature:
1. Click on the menu option "Indexes" at the top of the page:
2. Then select "Major Categories" from Index drop-down list and click the BROWSE button.
3. Browse the list for a category that fits your topic. Select a category and click the ADD button. If you select more than one category (for instance, if two or more categories are related), keep the Boolean operator "OR" selected.
4. After you click the ADD button, your category terms will appear in the search box at the top of the page. Click the SEARCH button. Your search results will appear.
5. To limit your result set, add appropriate terms to the other search boxes, as in this example:
GeoRef terms for geographic areas in the United States are often names of counties. See this example record:
If your topic relates to a specific geographic area, determine all the possible the county names (use an atlas or a map) for your area under study and then use the county names as search terms. You may also need to add the term for the state if a county name is a more common name.
The GeoRef Thesaurus is useful to help you pick the correct terms that describe a process, geologic term or geographical area. This is particularly helpful if you do not know the exact spelling of a term.
Click on the menu option "Thesaurus" at the the top of the page.
Search for the term (or an approximation of the term) and ADD the term(s) to your search.