Physical Oceanography Study Guide

Abyssal plain

A flat region of deep ocean basins.

Ocean ridge

A long, continuous mountain range on the seafloor, often of volcanic origin at a point or line of separation in the earth's crust.

Atoll

A ring-shaped coral reef surrounding a lagoon, resting on submerged volcanic islands.

Ocean trench

A deep cut or trench in the seafloor, usually close to where continental shelves and seafloors meet.

Brackish water

A mixture of fresh and saline (salt) water.

Pycnocline

The change in density with depth; encompasses both the thermocline and the halocline.

Briny water

Water with a high concentration of salt.

Reef

A shallow rock or coral formation often exposed at low tide.

Continental shelf

The land forming the shallow seafloor extending outward from the edge of a continent.

Salinity

Amount of dissolved salts present in water, measured in parts per thousand (ppt).

Continental slope

The sloping front of a continental shelf; the place where the continent ends.

Sea ice

Frozen ocean water.

Convection currents

Currents made by the rising of warm water and the sinking of cold water.

Seamount

An isolated undersea hill or mountain.

Current

A body of water or air moving in a definite direction.

Spring tide

Tides that occur when the moon is full and aligned with the sun.

Deep current

Currents that occur deep within the ocean, caused by differences in density or temperature.

Storm surge

Occurs when strong winds created by storms push ocean water onto land.

Density (in relation to currents and ocean water)

How compact water’s molecules are together.

Surface current

Ocean water moves in predictable ways along the ocean surface due to winds.

Ebb tide/current

When water flows away from the shore; the period of time between high tide and low tide.

Temperature (in relation to currents and ocean water)

Refers to the measurement of how warm or cold ocean water is.

Estuary

A river mouth or channel where fresh water from land mixes with seawater.

Thermocline

The transition layer between warmer water at the surface and cooler deep water.

Flood tide/current

When water flows towards the shore; the period of time between low tide and high tide.

Thermohaline circulation

Cold salty water in polar regions sinks, pulling in surface water that becomes cold and salty, driving deep water toward the surface.

Global conveyor belt

The constantly moving system of deep-ocean circulation driven by temperature and salinity.

Tidal waves

Large tides caused by underwater earthquakes, volcanic eruptions, etc.

Gyre

A major spiral of ocean-circulating currents; circular patterns of surface currents in the world's oceans.

Tides

Ocean waves caused by the gravitational pull between the Sun, Moon, and Earth.

Halocline

The change in salinity that creates a density barrier preventing mixing between surface water and deeper water.

Tsunamis

A series of waves generated by a large and sudden displacement of ocean water.

Lagoon

A shallow body of quiet water almost completely cut off from the open ocean.

Upwelling

When cold, nutrient-rich water moves towards the surface.

Neap tide

Tides that occur when the moon is in its 1st and 3rd quarters.

Waves

Rhythmic disturbances on the ocean's surface.

Ocean basin

A large depression in the earth's crust that holds the water of an ocean.

Wind-driven waves

Waves created by wind blowing across the surface of the ocean.