Ocean Currents What do we know about ocean currents? What conditions promote the development of ocean currents?

A current is a large stream of water that flows through the ocean Currents A current is a large stream of water that flows through the ocean Two types of currents Surface Currents Deep Currents

Surface Currents “rivers” of water on the top layer of the ocean

What Causes Surface Currents? 1. Driven by GLOBAL WINDS Like polar easterlies, prevailing westerlies, trade winds, etc The Coriolis Effect - winds curve because of Earth’s rotation Insert video

What Causes Surface Currents? 2. Continents  They get in the way! Gyres- Are caused when the continents deflect (bounce) the ocean currents, causing them to move in giant circles. GYRES = CIRCLES Great Pacific Garbage Patch  caused by a gyre Insert video clip about gyres and the pacific garbage patch

Which surface current is off the Georgia coast? The GULF STREAM

Surface Currents and Climate Warm ocean currents bring warm climate

Deep Currents Slow-moving currents below the water’s surface “Earth’s Conveyor Belt”

What causes deep ocean currents? 1. Temperature- Warm water rises and cold water sinks (remember convection currents!)

What causes deep ocean currents? 2. Differences in salinity (saltiness) More salt = more dense = sinks Less salt = less dense = rises COMBINE THEM  water moves!

Currents – Not Always a Good Thing Gulf Oil Spill Estimates = 800,000 gallons per day. If spill had continued, there is enough oil in that pocket to last for 7 years.

Oil Spill in the Loop Current

Oil Spill in Loop Current

Currents density salinity temperature saltier equator convection current salinity heat equator density temperature saltier Deep ocean currents are caused by differences in the ___________ of ocean water. The density of ocean water depends on its ______________ and _______________. As deep ocean currents reach the poles the water cools and gets ______________, which makes it denser causing it to sink. This cool water then flows across the bottom of the ocean back to the ______________ where it is warmed again starting the _____________ ___________ over again. This is the way that ___________ is distributed around the globe. density salinity temperature saltier equator convection current heat