[Free Registration/Login may be required to access all resource tools.] Discover how scientists learn about Earth's interior using seismic waves, meteorites, density, and the magnetic field. Additional resources are available for download.

[Free Registration/Login may be required to access all resource tools.] Traces changes in Earth's climate through Earth history, especially in the past 2,000 years.

[Free Registration/Login may be required to access all resource tools.] Presents the way geothermal energy is harnessed and some of its benefits and costs. Downloadable resources are also available.

[Free Registration/Login may be required to access all resource tools.] Covers metamorphic rocks, which form from previous rocks exposed to heat and/or pressure.

[Free Registration/Login may be required to access all resource tools.] Looks at how ocean currents transfer heat from one place to another.

[Free Registration/Login may be required to access all resource tools.] Studies the effects of altitude and mountain ranges on weather and climate.

[Free Registration/Login may be required to access all resource tools.] Looks at how heat is transferred in the atmosphere.

[Free Registration/Login may be required to access all resource tools.] Looks at how El Nino and La Nina affect the climate.

[Free Registration/Login may be required to access all resource tools.] Elaborates on radioactive decay as a tool for determining the age of certain minerals and other materials, including the limits of the technique.

[Free Registration/Login may be required to access all resource tools.] Introduces Steno's laws, which allow scientists to decipher the geological events that occurred and the order in which they took place, including how the relative...

[Free Registration/Login may be required to access all resource tools.] Describes some factors that lead to long-term climate changes.

[Free Registration/Login may be required to access all resource tools.] Describes the features of intrusive and extrusive igneous rocks that cool slowly and rapidly, respectively.

[Free Registration/Login may be required to access all resource tools.] Discusses the impacts of hazardous waste on the environment and human health, and the provisions of the Superfund Act.

[Free Registration/Login may be required to access all resource tools.] Presents the classifications of igneous rocks based on silica content.

[Free Registration/Login may be required to access all resource tools.] Distinguishes how to tell which rock unit is older than the ones around it and so reveal the geologic history of the region.

[Free Registration/Login may be required to access all resource tools.] Describes the various instruments that scientists use to measure weather conditions, including advanced tools like satellites and radar.

[Free Registration/Login may be required to access all resource tools.] Describes features of the seafloor and how they are mapped by echo sounding. It touches upon the continental margin as well.

[Free Registration/Login may be required to access all resource tools.] Presents information on the compounds that pollute the air, their sources, and the regions in which air quality is chronically bad.

[Free Registration/Login may be required to access all resource tools.] Explains how natural selection favors certain traits in a population so that the organism adapts to its environment, and that changes in the genes over time cause...

[Free Registration/Login may be required to access all resource tools.] Describes types of mining, their environmental costs, and reclamation.

[Free Registration/Login may be required to access all resource tools.] Describes the mostly massive features created by glacial erosion and deposition.

[Free Registration/Login may be required to access all resource tools.] Describes the sources of water pollution, such as municipal, industrial, and agricultural.

Overview of the basic concepts behind evolution, such as gene variation and adaptations.[Free Registration/Login may be required to access all resource tools.]

[Free Registration/Login may be required to access all resource tools.] Explains what groundwater is, aquifers, recharge, and fossil water.