A ring-shaped island, including a coral rim that encircles a lagoon. There may be coral islands or cays on the rim.
The farthest point on each of its tributaries upstream from its mouth/estuary into a lake/sea or its confluence with another river.
A narrow body of water that connects two larger bodies of water.
The continuous, predictable, directional movement of seawater driven by gravity, wind (Coriolis Effect), and water density.
A shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses
A long, deep, narrow body of water that reaches far inland. They are often set in a U-shaped valley with steep walls of rock on either side.
A flat, elevated landform that rises sharply above the surrounding area on at least one side.
A narrow strip of land that connects two larger landmasses and separates two bodies of water.
A portion of the ocean that penetrates land. They are generally larger and more deeply indented than bays.
A large, perennial accumulation of crystalline ice, snow, rock, sediment, and often liquid water that originates on land and moves down slope under the influence of its own weight and gravity.
A recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, or a lake.
A deep, narrow valley with steep sides.
A flat-topped mountain or hill. It is a wide, flat, elevated landform with steep sides – the top looks like a table.