The Internet resources listed below are primarily gateways or portals to geosciences resources. Here are a few. To find more, do a Google search on your topic.
An applied research institute of Indiana University providing information about Indiana geology. The Indiana Geological Survey publishes reports, maps, bulletins, guidebooks, and open-file studies on Indiana geology.
This site includes resources covering: floods, ground water, water quality, earthquakes, volcanoes, geologic mapping, land cover, minerals, natural contaminants, human impacts, etc.