- gas
- A substance that is not a solid or a liquid. A gas has no shape or volume and can expand without limit.
- geologic hazard
- A naturally occurring or man-made geologic condition that presents a risk or is a potential danger to life and property.
- geologic map
- A map on which is recorded geologic information, such as the distribution, nature, and age relationships of rock units, and the
occurrence of structural features, mineral deposits, and fossil localities.
- geology
- The scientific study of the origin, history, behavior, and structure of the Earth.
- global warming
- An increase in the average temperature of the Earth's surface, which occurs following an increase in greenhouse gases.
- greenhouse effect
- A complex natural process that takes place when gases in the Earth's atmosphere, including water vapor, allow heat energy from the Sun to pass through to the land and oceans. Heat energy radiating from the Earth's surface is absorbed by atmospheric gases, known as greenhouse gases, and is re-radiated back to Earth instead of escaping into space. This natural process may be affected by human activities, such as emitting large quantities of carbon dioxide into the atmosphere.
- greenhouse gases
- Gases that absorb heat re-radiated from the surface of the Earth. The greenhouse gases are carbon dioxide, chlorofluorocarbons (CFCs), methane, nitrous oxide, ozone, and water vapor.
- ground water
- Water that is held in the rocks and soil beneath the surface of the Earth. Ground water feeds wells and springs.
- gulf
- A large arm of an ocean or sea extending into a land mass.
|
