When Mount St. Helens erupted on May 18, 1980, the top 400 meters (1,300 feet) of the volcano disappeared in a blast that covered more than 390 square kilometers (150 square miles) and sent thousands of tons of ash into the upper atmosphere. This collection of still images and video depict before-and-after scenes of Mount St. Helens and its surroundings, allowing viewers to witness the results of ... Full description.

Humans depend on freshwater for drinking as well as for domestic, agricultural, and industrial uses. Careless and wasteful use of this renewable but high-demand natural resource contributes to water depletion. This video segment provides a look at a house in Tuscon, Arizona that is equipped with water conservation devices that cut its household water consumption in half. There is also discussion of ... Full description.

This activity will help students describe the amount and distribution of water in the Earth's oceans, rivers, lakes, groundwater, ice caps, and atmosphere. Students will recall that the Earth is also known as the water planet, as approximately 70 percent of its surface is water. They will discover that all of these forms of water are part of a dynamic and interrelated flow called the hydrologic cycle, ... Full description.

This six week project asks students to create a webpage about one of the following regions: desert, prairie, plains, forest, or mountains. Topics include regional climate, weather, agriculture, species, and environmental issues. This project combines students' research abilities with writing and speaking skills as they present their complete webpages to their classmates. The site provides links to ... Full description.

This video segment points out that we are consuming fossil fuels at a rate far faster than they can be produced in the Earth, and that combustion of these materials to produce energy releases carbon dioxide, a greenhouse gas. It also discusses some current and future alternatives for supplying energy, and describes some of the benefits and limitations inherent in each. The segment is six minutes nine ... Full description.

For this activity students read the newspaper on a daily basis, listen to news on the radio, or watch television, to acquire material related to the earth sciences. They will look for natural hazards (earthquakes, volcanoes, landslides, hurricanes, etc.), human-made hazards (urbanization, compromised engineering projects, etc.), environmental issues, or resource extraction issues which all appear ... Full description.

Farmers and rivers have a close, though not always friendly, relationship with one another. Rivers can create prized farmland, but they also flood fields and the communities built alongside them. Farming practices may also contribute to an increase in the magnitude and intensity of river flooding. This video segment explains the issue of flooding as seen in the Mississippi River watershed and suggests ... Full description.

In this activity students use a map of the Mississippi Watershed to label and count rivers and the states associated with them in a particular watershed. Students "build" the watershed in a pan using modeling clay or soil. They use small objects to represent things such as pollutants, litter, fertilizers, sediments, etc., that could be transported by water flowing in the drainage system. Students ... Full description.

In this lesson students investigate the relationship between sediment sampling and ocean pollution as they discover how scientists collect and study sediment on the bottom of the ocean. They will also find out if the sediment sampling methods used by scientists can be used to detect pollution. They will learn about the proximity of the Hudson Shelf Valley and the Hudson Canyon to the New York City ... Full description.

In this activity, students build a model to demonstrate how aquifers are formed and ground water becomes polluted. For younger students, the teacher can perform this activity as a demonstration, or older students can perform it themselves. A materials list, instructions, and extension activities are provided. Full description.