Ocean currents — the continuous, directed movement of ocean water — affect regional climates and alter the biological and chemical characteristics of seawater.
Over Earth’s 4.5 billion-year history, tectonic upheavals and colliding plates formed mountain ranges and carved out basins. Forces of erosion and weathering have been at work to break down these landforms. Records of these processes are imprinted on the land and define distinctive landscapes around the United States and in its national parks.
Citizen scientists involved in the Geological Society of America's EarthCaching project (http://www.earthcache.org
) use GPS technology and latitude and longitude coordinates to find special places on the Earth. This activity will help you learn how to find locations using latitude and longitude.
Ever play with clay? Using a common modeling compound, you can form a “volcano” and examine its topography to predict which way lava will flow down its slopes. You could also investigate mud flows or debris flows.
Most people associate petroleum with transportation — but we are surrounded by thousands of other everyday products that come from this vital natural resource. A typical 42- gallon barrel of crude oil yields about 20 gallons of gasoline and 4 gallons of jet fuel. What products come from the other 18 gallons?
Human beings have been linked to earth materials since prehistoric times. They used caves for shelter, shaped rocks into stone implements, and later refined metals to make tools. Beyond practical purposes, Earth materials also were used to make pigments for paint. Rock walls became canvases where ancient artists expressed themselves. In this exercise, we will explore the link between Earth materials and art.
How can a cave form from solid rock? Most caves are found in limestone, a rock made of materials of calcium carbonate. This rock is unusual because the solid minerals it is made of easily dissolve in weak acids. The most common weak acid in the environment is actually water!
What is sea ice? It is simply frozen ocean water.
Why is sea ice important? While it occurs mainly in polar regions, sea ice influences our global climate. Changing amounts of sea ice can affect ocean circulations, weather patterns, and temperatures around the world. Sea ice insulates the relatively warm ocean water from the cold polar atmosphere, except where cracks in the ice allow for the exchange of heat and moisture. The exchange of salt between sea ice and the ocean alters the density of ocean waters, thus influencing ocean circulation. Many animals, such as polar bears, seals, and walruses, depend on sea ice for their habitat. These species hunt, feed, and breed on the ice.
Satellites provide the best way to observe sea ice, the factors that affect sea ice, and the ways sea ice affects global climate. Scheduled to launch in 2010, NASA’s Aquarius mission will measure global sea surface salinity with unprecedented resolution. Even small variations in sea surface salinity — the amount of salt present near the ocean’s surface — can have dramatic effects on sea ice, the water cycle, and ocean circulation.
Scientists use seismic technology to map patterns of rock formations below the surface of the Earth. Different types of rocks affect sound waves. Geologists use these sound waves to locate rocks that may contain oil and/or natural gas.
You can explore this principle with a tuning fork and various rocks. Gently strike a fork against the rocks. Note variations in sounds produced by different rocks. How could scientists use this information to help map the rock layers underground? In the following activity, you will explore one way scientists find oil beneath the Earth’s surface.
In this activity, students will conduct experiments or participate in demonstrations to answer questions about sky and weather phenomena. Students also will analyze and present data.