Ocean Currents and El Nino Effects

This lecture covers the dynamics of ocean currents, including surface currents, gyres, and thermohaline circulation. It explains how these currents affect global climate and marine ecosystems. The lecture also discusses the El Nino phenomenon and its impact on weather patterns worldwide.

What two phenomena primarily drive ocean currents?

• Unequal heating and the Coriolis effect

• Gravity and the moon's pull

• Tides and wind patterns

• Earth's rotation and magnetic fields

In which direction do gyres move in the Northern Hemisphere?

• Counterclockwise

• Clockwise

• North to South

• East to West

What is the primary effect of upwelling on marine ecosystems?

• It causes ocean currents to reverse

• It decreases water temperature

• It brings nutrients to the surface

• It increases salinity

What two factors are involved in thermohaline circulation?

• Sunlight and evaporation

• Wind and gravity

• Salinity and temperature

• Temperature and pressure

How long does it take for water to complete a loop in thermohaline circulation?

• 100 years

• 500 years

• 10,000 years

• 1,000 years

What is the primary cause of El Nino?

• Increased volcanic activity

• Reversal of trade winds

• Changes in Earth's orbit

• Increased solar activity

During an El Nino event, which direction do the surface currents in the tropical Pacific move?

• Eastward

• Westward

• Northward

• Southward

What is a significant consequence of El Nino on marine life along the South American coast?

• Increased salinity

• Higher water temperatures

• Decreased nutrient availability

• Increased fish populations

How often does El Nino typically occur?

• Every 10 years

• Every 3 to 7 years

• Every year

• Every 20 years

What is the effect of El Nino on the southeastern United States?

• Lower temperatures

• Increased precipitation

• Decreased precipitation

• Higher temperatures