| A | B |
|---|
| landforms | The shapes on Earth’s surface |
| topography | Shape, height, and arrangement of land-forms in a certain place |
| plate tectonics | The theory that Earth’s surface is divided into several major, slowly moving plates or pieces |
| subduction | The movement of one of Earth’s heavier tectonic plates underneath a lighter tectonic plate |
| earthquakes | Sudden, violent movement along a fracture within Earth’s crust |
| lava | Magma that has broken through the crust to Earth’s surface |
| fault | A fractured surface in Earth’s crust where a mass of rock is in motion |
| weathering | The process of breaking rocks into smaller pieces through heat, water, or other means |
| erosion | The movement by water, ice, or wind of rocky materials to another location |
| plain | A nearly flat area on Earth’s surface |
| alluvial fan | A fan-shaped landform created by deposits of sediment at the base of a mountain |
| floodplain | A landform of level ground built by sediment deposited by a river or stream |
| deltas | Landforms created by the deposits of sediment at the mouths of rivers |
| glaciers | Large, slow-moving sheets or rivers of ice |
| terraces | Horizontal ridges built into the slopes of steep hillsides to prevent soil loss and aid farming, |
| tributary | Any smaller stream or river that flows into a larger stream or river |
| groundwater | The water from rainfall, rivers, lakes, and melting snow that seeps into the ground |
| aquifers | Underground, water-bearing layers of rock, sand, or gravel |
| water cycle | The circulation of water from Earth’s surface to the atmosphere and back |
| evaporation | The process by which heated water becomes water vapor and rises into the air |
| water vapor | The gaseous form of water |
| condensation | The process by which water changes from a gas into tiny liquid droplets |
| precipitation | The process by which water falls back to Earth |
| acid rain | A type of polluted rain, produced when pollution combines with water vapor |
| ozone layer | A form of oxygen in the atmosphere that helps protect Earth from harmful solar radiation |
| global warming | A slow increase in Earth’s average temperature |
| greenhouse effect | The process by which Earth’s atmosphere traps heat |
| weather | The condition of the atmosphere at a given place and time |
| climate | The weather conditions in an area over a long period of time |
| prevailing winds | Breezes that consistently blow in the same direction over large areas of Earth |
| currents | Giant streams of ocean water that move from warm to cold or from cold to warm areas |
| rain shadow | The dry area on the leeward side of a mountain or mountain range |
| renewable resources | Resources, such as soils and forests, that can be replaced by Earth’s natural processes |
| nonrenewable resources | Resources, such as coal and oil, that cannot be replaced by Earth’s natural processes |
| deforestation | The destruction or loss of forest area |
| reforestation | The planting of trees in places where forests have been cut down |
| fossil fuels | Nonrenewable resources formed from the remains of ancient plants and animals |
| petroleum | An oily liquid that can be refined into gasoline and other fuels and oils |
| hydroelectric power | A renewable energy resource produced from dams that harness the energy of falling water to power generators |
| geothermal energy | A renewable energy resource produced from the heat of Earth’s interior |
| solar power | Heat and light from the sun |
