1. Currents Andy Holmes, Jay Karon, Ina de Weerdt, Chun Hoi Chan, Alex Burns

2. Major Currents

3. Factors of Currents • Wind • Planet Rotation • Temperature • Salinity • Gravitational Effects of the Moon • Factors together form a “conveyor belt” • Gyres are circular currents

4. Salinity • Average ocean salinity is 3.5% • Varies from32-37 ppt • Factors • Precipitation • Evaporation • River Run-Offs • Ice Formation Dead Sea – Salinity 354 ppt

5. Effects of Salinity • High Salinity • Increases evaporation point • Increases density • Low Salinity • Decreases evaporation point • Decreases density • Density drives deep-sea currents

6. Upwelling & Downwelling • Upwelling • Cold water rises • Elevates rich nutrients • Ex. Warm gulf stream meets the Labrador current • Downwelling • Warm water descends • Brings oxygen down

7. Rich Areas • Good circulation “refreshes” water • Ex. Summer upwelling from Northwesterlies off the coast of Vancouver Island • Forms the Race Rocks • Humboldt Current from South Chile to Peru. • Great marine life diversity • Large fisheries

8. More importantly it helped Nemo return home Upwelling of the East Australian Current helped form the Great Barrier Reef

9. Hydrothermal Vents • Spots in the crust leak magma, super- heating the surrounding water • Found near plate boundaries and hotspots • Creates unique ecosystems • Temperature around 400°C

10. Trash Island • Located in the north Pacific Ocean between Hawaii and California • This area is in the middle of the north Pacific sub-tropic gyre • Center of gyre is calm • Circular motion draws in debris and prevents escape • Size estimates vary wildly

11. Issues • Global warming • Increasing temperatures affect currents • Pollution • Gets trapped and creates environmental hazards • Drilling • Spills are dispersed through currents

12. NASA’s Animation

13. Q1. Currents are found around ____. the equator. the Tropic of Cancer. the Tropic of Capricorn. All the above.

14. Q2. Upwelling delivers ______. Higher temperature water to the surface. Cooler temperature water to the surface. Nutrients to sustain organisms. Both b & c All the above.

15. Q3. What current helped Nemo find his way home? The Gulf Stream. The Northwesterlies. The Humboldt. The East Australian Current.

16. Q4. Where is Trash Island located? North Pacific Ocean. Eastern Indian Ocean. North Atlantic Ocean Antarctic Ocean.

17. Q5. What is a gyre? A hydrothermal vent. A rectangular current. A tool to measure salinity. A circular current.

18. Q6. What is average ocean salinity? 7% 20% 3.5% 0.8%

19. Q7. A hydrothermal vent is most similar to what? A cave. A volcano. A hurricane. A sea anemone.

20. Name two factors of currents. Wind Planet Rotation Temperature Salinity Gravitational Effects of the Moon

21. Name two effects of high salinity levels. • Creates denser water • Creates convection currents • Increases evaporation point • Results in less precipitation • High salinity can be dangerous to organisms

22. Critical Question ? The world faces the increasing threat of rising global temperature. How do ocean currents relate to this danger?

23. Works Cited Textbook http://www.ehow.com/about_5517246_salinity-impact-oceans-currents.html Education.nationalgeographic.com/trashisland http://en.wikipedia.org/wiki/Upwelling http://science.nasa.gov/earth-science/oceanography/physical-ocean/salinity/ http://geography.about.com/library/misc/blcurrents.htm NASA's Goddard Space Flight Center Disney