Friday, February 1 st

1. Friday, February 1st Deep ocean currents can be caused mostly by? • Coriolis effect • Upwelling • Surface currents going deeper • Differences in density

2. ATTENTION Ocean Test will be Tuesday February 5th!!!

3. Today’s Mission Review your notes and review on: Tides, Waves, Currents

4. #1 Waves What causes waves? Where do you find most waves?

5. Waves in the news! http://abcnews.go.com/WNT/video/daredevil-surfer-tackles-largest-wave-18349457

6. Wind causes most waves More wind = bigger waves Longer distances = bigger waves

7. Describing a wave

8. Wave SIZE Depends on 3 Things • Strength of wind • Length of time wind blows • Distance over which the wind blows

9. Do waves carry WATER to the shore? NO! The water does not move toward the shore. If it did all the water would be on the shore!

10. So, What moves toward the shore? The ENERGY! The energy moves toward the shore, but the water itself remains where it was.

11. Does the water move at ALL? YES! How? • The water particles move in a circular motion.

12. The deeper you go the smaller the circles. • Below a certain depth, the water does not move at all! EX. Does a submarine get tossed around during a storm? No!

13. Sandbars • As the waves slow down, they deposit the sand on the shallow, underwater slope. This creates a SANDBAR

14. RIP CURRENTS A rush of water that flows rapidly back to sea through a narrow opening (water breaks through a sandbar)

15. SWIM PARALLEL

16. A tsunami (pronounced soo-NAA-mee) is a series of waves (called a "wave train") generated in a body of water by a pulsating or abrupt disturbance that vertically displaces the water column.

17. Tsunami's are also mistakenly referred to as tidal waves as they often resemble a tide that keeps rising, rather than cresting waves when they reach shore. However, as they are not actually related to tides the term may be misleading, and its use is discouraged by scientists.

18. Tsunamis are created when: • Seafloor quickly changes shape • Water is displaced • Waves are formed as the displaced water mass, which is affected gravity, tries to move back Anthony Liekens 15:30, 28 Dec 2004 (UTC)

20. Characteristics • Move at high speeds • Can travel enormous distances with little energy loss • Can cause damage thousands of miles from its origin • May be several hours between its creation and its impact on the coast

21. #2 Tides What causes Tides? What’s the difference between Neap and Spring tides?

22. Tides are caused by the moon and sun’s gravity pulling on the Earth’s water Earth, Sun and Moon

23. Watch carefully! This is a view from above the North Pole. How many high tides and low tides do we have each day? If you are at the beach and high tide is at 6:00am, about what time would low tide be? When would the next high tide be? This is what is happening at the beach!

24. As the moon pulls on the Earth’s water, it rises and falls. Have you had a “tide” experience at the beach?

25. The Math: • There are 2 high tides and 2 low tides every 24 hours • This means the tide goes from high to low in about 6 hours. • This also means that every there is a 12 hour time period between each high and low tide Time Chart: 7:00 am high tide ________ low Tide ________ high tide ________ low tide

26. Spring tides • Are tides that are especially high or low during a 24 hour period. • They are caused by the earth, moon, and sun lining up in a straight line and the pull on the oceans is especially strong. Neap tides • Tides that show very little change between high and low tide during a 24 hour period. • They are caused by the earth, moon, and sun forming a right angle and the pull on the oceans is weak

27. Spring Neap

28. #3 currents What causes surface currents? What causes deep currents?

29. Currents – an ocean current is a “river” of moving water with the ocean. • The water in the current has the same properties and does not mix much with the rest of the ocean. • All ocean currents flow in predicable patterns http://www.youtube.com/watch?v=JpV7NIJTxD0

30. Surface Currents • Surface currents, like waves, are driven and determined by wind and the Corioliseffect • Coriolis effect – the apparent curving of the path of a moving object from an otherwise straight path due to the Earth’s rotation. • Northern hemisphere: clockwise • Southern hemisphere: Counter-clockwise

31. Coriolis Effect Because the Earth is spinning, the ocean water and wind trying to travel in a straight line from one place to another gets pulled off course.

32. Coriolis Effect Notice that the ball in the center of the disk is trying to roll toward the red dot. But because the disk is spinning under the ball, it never makes it to the red dot but is “deflected” to the side. The top view is showing that the ball actually moves in a straight line. The bottom view is showing the path the ball took across the disk. http://en.wikipedia.org Link to a Coriolis Effect animation Link to a Coriolis Effect animation part 2

33. The current that affects the eastern USA is the Gulf Stream! Can You Find The gulf stream? It is a “river” of warm water in the Atlantic Ocean!

34. Ocean currents can affect climate by warming or cooling the air above the current. • Example – England is warmer than it should be based on its latitude because of the Gulf Stream current coming from the southern USA.

35. Deep Ocean Currents • Caused by the change of density • Temperature and salinity effects the density • Caused from the polar ice caps