Research procedures and instrumental means to measure, collect data and samples, and observe in the natural areas where the materials, phenomena, structures, or species being studied occur.
Studying 28 species of warblers, flycatchers, tanagers, and vireos, we find the birds relied on the flowering of honey mesquite to detect the availability of insects they eat.
Airborne electromagnetic surveying is used to estimate the character of the permafrost by measuring and monitoring the electrical resistivity, which is affected by lithology, temperature, water, and ice.
The report describes a strategy for monitoring, modeling, and research activities to support management decisions to improve water-quality conditions in the Mississippi River Basin, reduce hypoxia in the northern Gulf of Mexico, and improve conditions for
Main page for accessing links for information and data on the San Francisco Bay estuary and its watershed with links to highlights, water, biology, wetlands, hazards, digital maps, geologic mapping, winds, bathymetry and overview of the Bay.
Explains acidity and acid rain and how it affects aquatic organisms. Describes the effect of acid rain on this national park, identifying areas that are at greater or lesser risk from acid rain.
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.
Overview of the Toxic Substances Hydrology Program role in investigating the occurrence and fate of agricultural chemicals with links to investigations, headlines, on-line fact sheets, new publications, bibliographies and photo gallery.