Description of datasets of AVHRR data available from the EROS Data Center in Sioux Falls, SD in three formats: High Resolution Picture Transmission (HRPT), Local Area Coverage (LAC), and Global Area Coverage (GAC).
Technical information on the Aircraft Scanners data set at the USGS EROS Data Center containing digital imagery acquired from several multispectral scanners collected over conterminous United States, Alaska, and NASA aircraft.
Clearinghouse for the description and availability of multiple geospatial datasets relating to Alaska from many federal, state and local cooperating agencies under the coordination of the Alaska Geographic Data Committee.
Online annual reports (since 1999) documenting hydrologic data for Pennsylvania gathered from USGS surface water and ground water data-collection networks and information on ordering paper copies of previous years.
Geospatial hydrologic and reference data covering the upper Mississippi River, provided in formats appropriate to geographic information systems (GIS) and used in long-term resource monitoring of the area.
Arsenic is a naturally occurring element in rocks, soils, and the waters in contact with them. It is found in ground water as the result of minerals dissolving from weathered rocks and soils. This site links to data, maps, and more.