Iowa Geological Survey Bureau, USA - - Website of the Geological Survey Bureau of the Iowa Department of Natural Resources, including a Geologic Sample Database (GEOSAM)with geologic information for 35,000 locations in Iowa.
NASA's Global Change Master Directory - - A comprehensive directory of information about Earth science data, including a broad coverage of the oceans, atmosphere, hydrosphere, solid earth, biosphere and human dimensions of global change.
Physical Geography sites on Internet - - Index of articles about Daylight Saving Time, the hydrologic cycle, El Nino, rivers, seasons, ice ages, and more topics in Physical Geograph.
USGS Global Change Research Program - - The U.S. Geological Survey's Global Change Research Program is an international source for ground-based and remotely sensed earth science data and information used by global change researchers and contributing to assessments of the potential effects of global change on society.