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OCEAN CURRENTS. Section 4 – Chapter 13. What is a current?. A curren t is a large stream of moving water. Currents actually MOVE water – waves do NOT move water. There are 2 main types of currents: Surface currents Deep currents. SURFACE CURRENTS.
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OCEAN CURRENTS Section 4 – Chapter 13
What is a current? • A current is a large stream of moving water. • Currents actually MOVE water – waves do NOT move water. • There are 2 main types of currents: • Surface currents • Deep currents
SURFACE CURRENTS • Affect water several hundred meters deep. • Driven mainly by the wind. • Most of them flow East or West
Coriolis Effect • The Coriolis Effect is the effect of Earth’s rotation on the direction of the currents. • Northern Hemisphere – currents flow to the right; clockwise • Southern Hemisphere – currents flow to the left; counterclockwise Click the Earth for video explanation!
The GULF STREAM • The largest, most powerful surface current in the Atlantic Ocean. • It carries warm water from Mexico to Carribean then northward along coast of US – at NC it curves outward due to Coriolis Effect!
Surface Currents Affect Climate • Warm/Cold water currents will warm or cool the air above them and influence the climate on land. • Air over warm currents tend to pick up moisture and bring rain to land. • Cold currents will cool the air which can’t pick up as much moisture which results in cooler, drier weather.
El Nino • Unusual wind patterns will change the currents flow in the Pacific Ocean. • It happens every 2-7 years. • This change causes weather patterns to shift towards more severe weather occurances like extra rainy(flooding/mudslides), mild winters, incident of tornadoes increases, etc.
Ocean Temp Comparison El Nino – Temps are higher
DEEP CURRENTS • Caused by differences in density of ocean water due to difference in temperature/salinity. • Flow more slowly than surface currents – one circuit around can take up to 1000 years! • Cold water flows from the poles towards the equator. • Sometimes called “thermohaline” currents or the “conveyor belt”
UPWELLING • Movement of cold, deep water upwards towards the surface. • Important b/c it brings nutrients from the ocean floor up towards the surface. • Fish & other organisms depend on this upwelling for their survival. • Many upwelling regions contain hundreds of schools of fish.