| A | B |
|---|
| Astronomy | The study of the universe. |
| Geology | The study of the origin, history, and structure of the Earth and the processes that shape the Earth. |
| Hypothesis | A possible explanation or answer to a question that can be tested. |
| Meteorology | The study of Earth's atmosphere, especially in relation to weather and climate. |
| Oceanography | The scientific study of the sea. |
| Density | The measure of how much matter is in a given amount of space. |
| Luster | The way a surface reflects light. |
| Mineral | A naturally formed, inorganic solid that has a definite crystalline structure and chemical composition. |
| Mohs Hardness Scale | A mineral's resistance to being scratched and the scale that indicates its relative hardness. |
| Streak | The color of a mineral in powdered form. |
| Igneous Rock | A rock that forms when hot, liquid rock, or magma, cools and solidifies. |
| Metamorphic Rock | A rock that has been changed by heat and pressure. |
| Rock | A naturally occurring solid mixture of one or more minerals and organic matter. |
| Rock Cycle | The continual process by which new rock forms from old rock material. |
| Sedimentary Rock | A rock that forms when sediment is compacted and cemented together. |
| Energy Conservation | The process in which we limit our energy. |
| Fossil Fuels | A nonrenewable energy resource formed from the remains of plants and animals that lived long ago. |
| Natural Resource | Any natural material that is used by humans. |
| Non-renewable Resources | A resource that forms at a rate that is much slower than the rate at which it is consumed. |
| Renewable Resources | A natural resource that can be replaced at the same rate at which the resource is used. |
| Absolute Age | The exact age an object formed. |
| Index Fossil | Fossils of organisms that lived during a relatively short, well-defined geologic time span. |
| Law of Superposition | Younger rocks like above older rocks in undisturbed sequences. |
| Relative Age | The age of an object compared to an object or event that is older or younger. |
| Uniformitarianism | The same geologic processes shaping the Earth today have been at work throughout Earth's history. |
| Asthenosphere | A plastic layer of the mantle on which pieces of the lithosphere move. |
| Continental Drift | The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present location. |
| Convection Currents | The movement of matter due to differences in density caused by changes in temperature. |
| Lithosphere | The outermost, rigid layer of the Earth. |
| Plate Tectonics | The theory that the earth's lithosphere is divided into tectonic plates that move around on top of the asthenosphere. |
| Deformation | The change in the shape of rock in response to stress. |
| Earthquake | The result of when a fault locks and pressure builds up until the rock breaks and the pressure is released. |
| Epicenter | The point on the Earth's surface directly above an earthquake's starting point. |
| Focus | The point inside the Earth where an earthquake begins. |
| Seismic Wave | Waves of energy that travel through the Earth. |
| Caldera | A large, semicircular depression that forms when the chamber that supplies magma to a volcano partially empties and the chamber's roof collapses. |
| Hot Spot | Volcanically active places on the Earth's surface that are far from plate boundaries. |
| Magma Chamber | A body of molten rock deep underground that feeds a volcano. |
| Vent | It is the opening where magma rises from the magma chamber through cracks in the Earth's crust. |
| Volcano | Areas of Earth's surface through which magma and volcanic gases pass. |
| Chemical Weathering | The process by which rocks break down as a result of chemical reactions. |
| Contour Plowing | To prevent erosion, a farmer plows across the slope of the hills. |
| Crop Rotation | Planting different crops the next year. |
| Mechanical Weathering | The breakdown of rock into smaller pieces by physical means. |
| Soil | A loose mixture of small mineral fragments, organic material, water, and air that can support the growth of vegetation. |
| Aquifer | A rock layer that stores groundwater and allows the flow of groundwater. |
| Divide | The area of higher ground that separates watersheds or drainage basins. |
| Drainage Basin | The area of land that is drained by a water system. |
| Groundwater | The water located within the rocks below the Earth's surface. |
| River | A large stream. |
| Beach | Any area of the shoreline made up of material deposited by waves. |
| Deposition | The process in which material is laid down. |
| Erosion | The process by which wind, water, ice, or gravity transports soil and sediment from one location to another. |
| Mass Movement | A movement of a section of land down a slope. |
| Sand Dune | The mounds of wind-deposited sand. |
