1. P LATE T ECTONICS P RODUCING O CEAN PROCESSES

3. Warm Water is LESS dense, so it RISES. Colder Water is MORE dense, so it SINKS. Convection- transfer of heat Earth and Convection

5. A BYSSAL PLAINS Flat areas of ocean floor Between ocean trenches and continental rises Formed by Mantle Convection Uneven rock surface becomes covered with fine-grained sediment Depth between 3000 & 6000 m below sea level

7. P LATE B OUNDARY D YNAMICS 1. Divergent 3 Boundaries: 2. Convergent 3. Transform

8. E FFECTS OF DIVERGENT BOUNDARY : Mid-Oceanic Ridges Underwater Mountain Ridges Formed by upward movement & spreading of underlying magma Sea Floor Spreading This is an eruptive fissure that was found several kilometers from the mid-ocean ridge.

9. D IVERGENT B OUNDARY : I CELAND (M ID -A TLANTIC R IDGE )

10. Mid-Atlantic Ridge, Iceland

11. I CELAND P LATE B OUNDARY

13. The East Africa Rift Valley is in a very early stage of development; above ocean, has created lakes The Red Sea is an example of a more completely developed rift. The plates have fully separated and the central rift valley has dropped below sea level

14. E VOLUTION OF D IVERGENT B OUNDARIES

15. E FFECTS OF CONVERGENT Zone of progressively deeper earthquakes Chain of Volcanoes Tsunamis Ocean Trench ( OCEAN -C ONT )

16. Older; denser plate Newer; less dense plate O CEANIC /O CEANIC Magma is less dense than basalt so it melts/fractures its way to surface causing eruptions Eventually islands form EX: Japan, Aleutian Islands, E. Caribbean Islands When 2 Oceanic plates collide; ______________________________ beneath the newer plate

17. O CEANIC /O CEANIC

18. E FFECTS Cleveland Volcano, Aleutian Islands

20. D EEPEST P LACE ON E ARTH One plate is forced under another (Subduction) Convergent Boundaries Long and narrow

21. Left: Trieste: bathyscaphe January, 1960 Right: James Cameron Green Machine March, 2012

23. D IVE TO C HALLENGER D EEP IN THE M ARIANA T RENCH http://youtu.be/Y2tm4 0uMhDI

24. E ARTHQUAKE Sudden release of energy in Earth’s crust, creating seismic waves Arises from Convergent, specifically Transform Boundaries If two plates are unable to slip past each other they LOCK, strain (energy) builds up When the plates start moving again, stored energy gets released

25. T RANSFORM B OUNDARY Plates slide past one another EX: 1. San Andreas Fault 2. Alpine Fault in New Zealand 3. Along the Mid-Atlantic Ridge

28. TSUNAMI Long wavelength wave produced by the sudden movement of a very large volume of water Convergent plate boundary, abrupt slippage of one plate against another results in an underwater earthquake and then a tsunami Deep Water= wave (small) travels quickly Shallow Water (coastal waters)= slows down and forms large, destructive waves Japan Tsunami 2011

29. V OLCANO Opening in Earth’s crust Hot gases and molten rock to escape Thinning of the crust= Divergent Mainly under the sea New sea floor Mid-ocean ridges If these rise above sea level, volcanic islands may be formed (ICELAND) Also form when plates move towards each other=Convergent

30. H YDROTHERMAL V ENTS

31. W HERE DO THEY OCCUR ? Discovered 1977 Divergent Boundary Deep Ocean Rift Valley/spreading center

32. H OW DOES IT WORK ?

33. 1. Cold seawater (2 O C) seeps into cracks and fissures along boundaries 2. Seawater continues to seep deeper into crust. 3. Water heats by underlying magma under the ocean floor 4. Hot Water is forced back up to ocean floor, carrying dissolved minerals All oxygen is removed Water becomes acidic Water picks up dissolved metals (Fe, Cu, Zn) & Hydrogen sulfide

34. H YDROTHERMAL VENTS FORM : 1. Hot hydrothermal fluid (less dense) (water), carrying dissolved metals & hydrogen sulfide. 2. Hydrothermal liquids exit vent/chimney & mix w/ cold seawater. a) Metals carried in fluid combine w/ sulphur to form black minerals (metal sulfides; AKA “black smokers”) 3. As it cools, the dissolved minerals starts to precipitate out 4. Precipitates form the chimney

38. H YDROTHERMAL VENTS Found at depths of over 2000 m Pressure is HIGH (over 200 atmospheres High Pressure= super heated water= reach temperatures higher than 100 degrees Celsius Discovering Hydrothermal Vents