Repeated observation or sampling at a site, on a scheduled or event basis, for study and analysis. In general, this category excludes sampling programs in which materials are obtained in the field and brought back to a laboratory for study and analysis.
U.S. map of real-time streamflow compared to historical values with links to U.S. maps and data of surface water, ground water, precipitation, river conditions and floods and other information on current and past water resources conditions.
Homepage of the Yellowstone Volcano Observatory with links to information about the observatory at Yellowstone National Park, volcanic history, photo gallery, monitoring data, publications and products, and Frequently Asked Questions (FAQs).
A program of studies with instruments to provide accurate and timely data and information on seismic events, including their effects on buildings and structures, employing modern monitoring methods and technologies.
The USGS Seismological Laboratory in Albuquerque installs and maintains a world network of seismograph stations, collects the seismic data, and evaluates seismic instruments. Site includes links to ASL publications, earthquake maps and seismic data.
Complex report on the interpretation of aeromagnetic data to study hydrogeology of the San Pedro basin, Cochise County, Arizona determining geologic structure, basin fill and depth to water. Online version of a CD-ROM publication.