Currents Flashcards
Define Ocean Current
An ocean current is any permanent or seasonal movement of water in the ocean.
What are currents?
Sources of Energy
How are Currents Generated?
These currents are generated by the forces acting upon the water: •Tides •Winds •Heat and salinity •The Earth’s rotation
Define Local Currents
Currents which have an impact on a individual parts of the coast.
Describe Rip Currents
A type of local current
Rip currents are flows of water which move away from the coast. They are caused when waves lead to water ‘piling up’ against the coast on an incoming tide. This water then ‘escapes’ back to open water often where there is a change of direction on the coast. They are extremely hazardous for swimmers.
What are the types of local current?
- Longshore Current
2. Rip Current
Describe Longshore Currents
A type of local current
Longshore currents are flows of water which run along (parallel to) the coast. They are caused when waves hit the coast at an angle. They lead to the transportation of sediment called longshore drift.
Define Global Current
Global currents have an impact on the planets oceans and weather systems as they transfer heat across the globe.
Describe The Gulf Stream/North Atlantic Drift
The Gulf Stream/North Atlantic Drift which flows past the western coast of the British Isles. Warm tropical waters flow north in a continuous ‘conveyer’ in which cold arctic waters flow southwards.
What is an example of a Global Current?
The Gulf Stream / North Atlantic Drift
Summary of Ocean Currents
- All ocean currents are movements in the oceans.
- All ocean currents are both sources of energy, inputs and flows/transfers in the coastal system
- All ocean currents are driven by a combination of winds, tides and the heat/salinity (salt content) of the water
