What elements and compounds are in the ocean besides water (H 2 O)?
Chemicals in the ocean The most common chemical in the ocean is sodium chloride – the same salt you put on your food! Salinity refers to how much salt is in water.
Salinity varies based on
Temperature and evaporation of water. When water evaporates, it leaves the salt behind making the water saltier (orange).
NOAA map of ocean's salinity. 2. Closeness to a “fresh” water source like a river or icebergs causes low salinity (blue). Continents in gray
http://www.nikon.co.jp/ The ocean changes as you get deeper. Less light so the living things must be able to live without light. More pressure due to the weight of the water above. It usually gets colder the deeper you go.
Density also affects the ocean. Salty water is more dense than fresh water. That means that fresh water will “float” on top of salty water and not mix well. Cold water is more dense than warm water. That means that warm water will “float” on top of cold water. Both these facts make water want to move. If cold water moves on top of warm water, the difference in density will make them slowly switch places. This causes currents .
Ocean Currents Deep currents are caused by differences in salinity, temperature, and shape of the ocean floor. Surface currents are caused by wind.
Surface currents are caused by wind. Surface currents near the equator are warm.
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. Coriolis Effect Also affects currents Don’t get it yet! More on the next slide!
Link to a Coriolis Effect animation part 2 Link to a Coriolis Effect animation Coriolis Effect Continued! 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. http://en.wikipedia.org 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.
Video on ocean waves and currents The current that affects the eastern USA is the Gulf Stream! Florida Gulf Stream It is a “river” of warm water in the Atlantic Ocean!
Video clip on how currents affect weather and climate
How do we explore the ocean?
Aqualung developed by Jacques Cousteau
Sonar – ( SO und Na vigation a nd R anging) Sonar tells us about the shape of the ocean floor by sending sound waves to the ocean floor and measuring how long it takes the energy to return. This tells us the topography of the ocean floor. Do you remember what topography is? Ship using sonar and what it discovered.
Submersible craft are built to withstand deep ocean pressure. Often they are unmanned and have robotic "arms." Video on deep ocean exploring
Satellites Video clip on satellite technology
What is the ocean floor like?
It is certainly not flat! Remember sea floor spreading? Atlantic Ocean Floor What do you think the different colors mean?
Another view of the features found in the ocean. Know these structures! Also called a seamount!
Formation of waves
Wind causes most waves More wind = bigger waves Longer distances = bigger waves Video clip on winds and waves
Watch the water droplet move in a vertical circle as the wave passes. The droplet moves forward with the wave's crest and backward with the trough.*
Tides Tides are caused by the moon’s gravity pulling on the Earth’s water. Video clip on tides
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? Watch carefully! This is a view from above the North Pole. This is what is happening at the beach!
As the moon pulls on the Earth’s water, it rises and falls. Have you had a “tide” experience at the beach?
What causes waves?
How do tides affect the Earth?
What is the most common salt in the ocean?
How do we use that substance?
What causes some parts of the ocean to be saltier than others?
What is the Gulf Stream?
Why does the Gulf Stream affect England’s weather?
Explain the Coriolis Effect.
How does sonar work?
Explain two ways we explore the ocean without going there ourselves.
What is the difference between the continental shelf and the continental slope?