Materials presented here outline basic concepts related to groundwater, answering questions like "What is groundwater?" and "What is an aquifer?" More detailed topics include groundwater quality, sources of contamination, engineering problems presented by groundwater, and safeguards to the groundwater supply. A bibliography and links to other water-related sites are included. A French translation ... Full description.

This tutorial contains animations that illustrate factors related to seasons on Earth. There are two sets of animations. The first set establishes viewpoints for observing the seasons and the second set studies the seasons on a planet with a 40-day year. In some of the animations, the user can control variables such as time. There is also a PDF file that features a learning guide about the Seasons ... Full description.

This site provides an introduction to the Missouri Springs of the Ozarks, a series of large springs that occur south of the Missouri River along the Ozark Uplift. There is general information on springs, including what they are, how they form, and their connection to the groundwater system. Photographs and brief descriptions are provided for the twenty largest springs in the state. There is also a ... Full description.