| A | B |
|---|
| volcano | an opening in the Earth's surface through which gases and lava escape from Earth's interior |
| strait | a narrow strip of water connecting two large bodies of water |
| island | a body of land surrounded by water |
| sea level | the level of the ocean's surface, used as a reference point when measuring heights and depths on Earth's surface |
| mouth | the place where a river flows into a lake or ocean |
| bay | part of an ocean or a lake partially enclosed by land |
| cape | a pointed piece of land extending into an ocean or a lake |
| harbor | a sheltered area of water, deep enough for docking ships |
| marsh | a soft, wet, low-lying, grassy area located between water and dry land |
| delta | a triangular area of land formed from deposits at the mouth of a river |
| flood plain | flat land alongside a river, formed by mud and silt deposited by floods |
| swamp | an area of land that is saturated by water |
| butte | a raised, flat area of land with steep sides, smaller than a mesa |
| oasis | a spot of fertile land in a desert, supplied with water by a well or spring |
| desert | a dry area where few plants grow |
| mountain | a natural elevation of Earth's surface with steep sides, higher than a hill |
| prairie | a large, level area of grassland with few or no trees |
| mesa | a wide, flat-topped mountain with steep sides, larger than a butte |
| steppe | a wide, treeless plain |
| valley | low land between hills or mountains |
| glacier | a large ice mass that moves slowly down a mountain or over land |
| cataract | a large powerful waterfall |
| canyon | a deep, narrow valley with steep sides |
| cliff | the steep, almost vertical edge of a hill, mountain, or plain |
| plateau | a broad, flat area of land higher than the surrounding land |
