Ocean currents are persistent movements of seawater that connect distant parts of the ocean. This lesson introduces their defining features, major types, and familiar examples.
An ocean current is a continuous, directed movement of seawater. Currents can travel horizontally across great distances or vertically between surface and deeper waters. Their routes and strength are affected by forces such as wind, the Coriolis effect, breaking waves, temperature and salinity differences, and the shape of coastlines and ocean basins.
All flashcards
What is an ocean current?
A continuous, directed movement of seawater, which may extend horizontally across an ocean or move vertically between ocean layers.
What is the difference between surface and deep-water currents?
Surface currents are generally driven by winds, while deep-water currents are generally driven by density differences related to temperature and salinity.
What are upwelling and downwelling?
Upwelling is the rise of deeper water toward the surface; downwelling is the sinking of surface water into deeper layers.
How do streams compare with drifts?
Streams transport larger masses of water at higher velocities; drifts are surface-water movements influenced by prevailing winds.
What makes the Antarctic Circumpolar Current notable?
It is the largest current, circling Antarctica uninterrupted, connecting ocean basins, and linking to vertical water exchange.
Quiz questions
In broad terms, how does Ekman-spiral rotation differ between hemispheres?Answer: It rotates clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
What do the labels warm and cold mean when classifying ocean currents?Answer: The water is warm or cold relative to the surrounding region.
Which statement best distinguishes the global conveyor belt from the AMOC?Answer: The global conveyor belt describes interconnected ocean circulation; the AMOC is a more specific circulation system.
What is one ecological effect of upwelling?Answer: It brings nutrients toward the surface, supporting plankton growth.
What can route planning based on surface currents help ships achieve?Answer: Shorter travel times, lower fuel use, and reduced emissions.
Based on the Wikipedia article Ocean current, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.