| A | B |
|---|
| landform | a physical feature on the Earth's surface |
| relief map | a map that uses shading to show elevations |
| topographical map | uses lines to show elevation |
| atmosphere | all of the gases around Earth |
| hydrosphere | all of the Earth's liquids |
| crust | the rocky layer of the Earth |
| mantle | solid (lithnosphere) and melted rock layer (asthenosphere) |
| outer core | liquid metal |
| inner core | solid metal |
| surveyor | a person who takes measurements of land |
| elevation | the height of land above sea level |
| benchmark | a permanent reference point |
| geologist | a scientist who examines rocks |
| plate tectonics | how forces deep within Earth can cause ocean floors to spread and continents to move |
| magma | hot, melted rock |
| fault | deep cracks |
| compression | squeezing or pushing together |
| volcano | an opening in Earth's crust |
| eruption | outpouring of melted rock |
| crater | cup-shaped depression |
| caldera | a volcano that collapses within itself and leaves a hole |
| lava | magma that reaches the Earth's surface |
| shield volcano | built by thinner, fluid lava |
| cinder-core volcano | built by thick lava |
| composite volcano | built by layers of ash sandwiched between layers of hardened lava |
| island chain | a line of volcanic mountains |
| hot spot | a stationary pool of magma |
| island arc | where an ocean-floor plate is pushed under another ocean-floor plate |
| earthquake | a sudden movement of the Earth's crust |
| focus | the place where an earthquake begins slipping |
| epicenter | the place where waves spread out on the Earth's surface directly above the focus |
| magnitude | the strength of an earthquake |
| tsunami | huge waves caused by an earthquake under the ocean |
| seismometer | an instrument that detects and measures waves produced by an earthquake |
| weathering | the process through which rocks or other materials are broken down |
| erosion | the process through which weathered rock is moved from one place to another place |
| glacier | a large mass of slowly moving ice |
| deposition | the process by which eroded materials are dropped off in another place |
| meander | gentle loops that form in slow moving rivers |
| sediment | particles of soil and rock that are carried along in water |
| floodplain | a place that is easily flooded when river water rises |
| levees | walls built to hold back water or prevent a flood |
| sandbar | a strip of land in the water |
