EPA site offers answers to what nonpoint source pollution is as well as provides links and information as to what concerned citizens can do about it.

Provides information on what to do after a flood to protect well water from contamination, the testing of private well water, and protecting private well water.

Find out about the EPA's Radiation Protection Division, which aims to protect the nation's people and environment from harmful exposure to radiation.

This concise site discusses the fact that wetlands are among the most productive ecosystems in the world, play an integral part in the ecology of the watershed, and also have a role in atmospheric maintenance.

Describes the themes and writing style of early New England historians. Clicking on the names at the bottom of each page will take you to information about individual historians.

A survey of the Quaker writers from the Colonial period extracted from The Cambridge History of English and American Literature.

An equation for the law of universal gravitation is stated. The weight equation (W=m*g) is related to the law. An interactive Javascript form allows the user to practice determining the force of gravity and the acceleration of gravity for various locations about the earth.

This video segment adapted from NASA's Goddard Space Flight Center discusses how a drought can have negative effects locally, for example by increasing the number of forest fires, and also globally, for example by impacting air quality thousands of miles away.

This video segment adapted from NASA's Goddard Space Flight Center shows how integral satellites are to everyday life and describes the different types, including orbital and geostationary.

This visualization adapted from NASA maps progressive global changes onto a rotating globe. Earth's atmosphere, hydrosphere, geosphere, and biosphere are shown to be dynamic and interconnected.

This video segment adapted from NOVA tells the tragic story of two Japanese seismologists who disagreed about the threat of earthquakes in the early twentieth century. Today, seismologists in California offer residents a probability of risk that an earthquake might occur.

In this video segment adapted from NOVA, animations are used to show how the hills around Los Angeles were formed by earthquakes at small thrust faults that extend outward from the larger San Andreas fault.5m 15s

In this video segment adapted from NOVA, a geologist digs a trench along the San Andreas Fault to reveal three thousand years of earthquake history. Information from the layers of sediment may help geologists to predict earthquakes.3m 19s

This video segment adapted from NOVA uses historical illustrations, photographs, and animations to explain how seismographs work, the difference between P and S waves, and the Richter scale.

This resource provides a good example of the differences between explicit costs and implicit costs using the ownership of a pizza restaurant as an example.

In this video produced for Teachers' Domain, Chi-An Wang, a mechanical engineering graduate from the Massachusetts Institute of Technology, describes her process when working with New Balance to design a new triathlon shoe.

"Follow Echo the Bat through Arizona and learn about remote sensing and use false-color satellite images to help you find Echo."

This game helps students to understand the concepts of changing supply, changing demand, and equilibrium price, as the price of bags of ice changes after a hurricane has swept through a community.

This classroom activity allows different boundaries for various groups of students to take a quiz. For example, some groups get more time, others may use a book or notes, etc. However, the roles of students will change just prior to the quiz, so students are forced to look for a more even or "fair" distribution of resources. This activity helps students to better understand the role of government in the distribution and protection of resources and opportunities.

In this series of short "headlines", each has a direct goal, but each also has an unintended externality or spillover.