Gathering information through periodic or continuous measurement in the field to provide a view of current conditions. In some instances, observations may not be subject to rigorous review before release; this will be noted in the documentation accompanying the data.
NWISWeb homepage for the National Water Information System providing access to water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, and Puerto Rico.
Description of seismograms and how they are produced by drum recorders and electronic instruments with real-time seismograms for Northern California and Long Valley, California and representative seismograms for types of earthquake activity.
Homepage for USGS national surface-water data with more than 850,000 station years of time-series data for stream levels, streamflow (discharge), reservoir and lake levels, surface-water quality, and rainfall plus real-time data and tutorial.
Homepage for USGS water quality information. The NWISWeb discrete sample database is a compilation of over 3.5 million historical water quality analyses in the USGS district databases. Also includes access to real-time data and a tutorial.