Oceanography

U.E.Q.: How do oceans shape our world?

Branches of Oceanography

Water Cycle

Questions

1. What are the four branches of oceanography?

2. What are the six steps of the water cycle?

Oceans

• Oceans comprise 71% of the Earth’s surfaces.

• Most of the world’s oceans are composed of 35 parts per million salts

Earth's Oceans

Questions

3. What are the Earth’s five oceans?

4. What percentage of the earth is water?

Content

• Wave Action• Tides• Ocean Water Chemistry• Currents and Climate• Ocean Zones and Habitats• Resources from the Ocean

The Perfect Wave

• Endless Summer

• Skimboarding • Biggest Wave

Wave Action

• Waves form when wind blows over the water’s surface.

• Wave Size depends on: – Wind strength– The time the wind blows– fetch - the distance the wind blows– water depth

• Wave Energy moves toward shore THE WATER DOES NOT

Questions

5. What are three things that a wave’s size depends on?

6. Does the water actually move in a wave?

Wave Action

• Observe an animation of wave motion.

Wave Action• Waves are characterized by:

– Wave Height (amplitude)– distance crest to trough– Wavelength – distance crest to crest– Wave propagation – direction of wave motion– Period – time it takes between two crests– Frequency – how many waves pass per second

• Observe wave frequency and period

Questions

7. What is wavelength?8. What is the period of a wave?9. What is the frequency of a

wave?

Wave Action

• Near Shore waves (Breakers):– Wave height increases– Wavelength decreases

• Tsunami– High wavelength, low frequency wave– Tsunami (5:11)– Timmy’s Tsunami Slideshow

• Wave Tank Demonstration

Tides

• Tides are the alternating rise and fall of sea level within a day

• Tides are caused by the interaction of the:– Earth– Moon – Sun

• How does this happen?– Gravity

Questions

10. What happens to wave height and wavelength as a wave breaks?

11. What is the wavelength and frequency of a tsunami?

12. What are the four things that effect tides?

Tides

• Daily Tide cycle– Observing

Tides at Cape Porpoise Harbor, Maine– Diurnal – one high, one low– Semidiurnal – two high, two low– Mixed – high, low, higher, lower

• High tides occur on points of Earth closest and furthest away from the moon; low tides occur at points between the two high tides

Tides

Tides

• Spring Tide – When the sun and moon align in any order; Largest difference between consecutive low and high tides

• Neap Tide – Sun’s pull is at tight angles to the moon’s pull; least difference between consecutive low and high tides

Questions

13. What does diurnal and semidiurnal mean?

14. What is the the difference between a spring tide and a neap tide?

Tides

• Reading a Tide Chart• Explanation of Tides (Bay of Fundy)• Observe Stop Motion of Bay of Fundy

Ocean Water Chemistry

• There are four major trends in Ocean water:– Temperature – with depth– Salinity – with depth– Density – with depth– Pressure – with depth

• Halocline - strong vertical salinity change• Thermocline – strong vertical temperature

change• Pycnocline – strong vertical density change

Ocean Water Chemistry

• Salinity – the amount of salt (NaCl) in a volume of water (Average 35 parts per thousand)

Questions

15. What are the four major trends in ocean water?

16. What is salinity?

Currents and Climate

• Observe: Eastern Australian Current• Surface currents v. Deep Ocean Currents• Wind can move the top 400 m of the ocean• Coriolis Effect – the effect of Earth’s rotation

on the direction of winds and currents– Curve to the right in the Northern Hemisphere– Curve to the left in the Southern Hemisphere

• Gyre - a circular or spiral motion.

Global Currents

Questions

17. What is the Coriolis Effect?18. What is a gyre?

Currents

• Gulf Stream– a surface current in

the North Atlantic– carries 4500 times

more water than the Mississippi River

– Each second, ninety million cubic meters of water is carried past Chesapeake Bay (US) in the Gulf Stream.

Currents

• El Nino– Every three to

seven years, El Niño occurs in the Pacific Ocean

– Nutrients normally found in the cold waters of the area disappear

Effectssevere coastal storms, heavy rainfall,

flooding and mud slides in California on the west coast of the United States.

droughts in Mexico and Central America, which led to forest fires that burned for long periods of time and sent heavy smoke north to the United States.

droughts in Australia which caused a water shortage.

unusually mild winters on the east coast of the United States.

droughts in the mid-west of the United States.

economic disaster to the Peruvian fisheries.

ice storms in eastern Canada and New England that caused some areas to be without power for over a month as rain froze on contact with telephone poles, wires, and trees. The weight of the ice caused poles to crumple and wires to break.

Currents

• Deep Ocean Currents – caused by density differences in the water

• Upwelling - ocean water moves from the deep sea to the ocean surface– Rich in nutrients plankton flourishes– Brings cold, damp, foggy weather

Currents

Questions

19. What effect does El Nino have on a habitat?

20. What is upwelling?

Ocean Floor

• Topography refers to the elevation on land

• Bathymetry is the depth of a depression.

• Sea level is an average level where topography and bathymetry both begin at zero for elevation and depth.

Ocean Floor

• The eastern United States coast is shallower than the west coast of the United States.

• The deepest trenches are found in the Marianas Trench in the south Pacific, which is the lowest point on the Earth’s surface.

• The Hawaiian Islands are just the tops of very high mountains.

Ocean Floor

• What is that?• Listen Dolphins

Ocean Floor

• Sonar (Sound Navigation and Ranging) Mapping– Uses sound waves to map out the

contours or the shape of the ocean bottom

– Sound waves return quickly if the ocean floor is close. 

– Sound waves take longer to return if the ocean floor is farther away

Questions

21. What is the difference between topography and bathymetry?

22. What is used to determine depth in the ocean and how does it work?

Ocean Floor

• Abyssal Plain – Smooth and nearly flat region of the ocean floor

• Seamount – mountain on the ocean floor that is completely under water

• Mid-ocean ridge – range of mountains on the ocean floor

• Continental Slope – incline at the edge of the continental shelf

• Trench – canyon in the ocean floor• Continental Shelf – shallow area of the

ocean floor extending outward from land

Ocean Floor

Questions

23. Name and define three of the six ocean floor features.

Ocean Zones

• Intertidal Zone (Littoral Zone)– Estuary,Mangrove Forest, and Salt Marshes

• Located usually where fresh water rivers reach salt water ocean water…brackish water

• Creatures must deal with changes in salinity, temperature, and water level

• Chesapeake Bay, Coastal Louisianna, Massachusetts– Sandy and Rocky Shores

• Creatures must be able to survive waves and tide changes

– Tide Pools• Form when tide recedes• Creatures must deal with changes in salinity and

temperature.

Ocean Zones

Intertidal Zone

Ocean Zones

• Neritic Zone– Starts at low tide line and extends to the

edge of the continental shelf.– Shallow water provides sunlight.– Coral Reefs

• Formed by tiny coral animals.• Algae provide food for coral…can only grow

in warm temps with plenty of sun!

– Kelp Forest• Grow in cold water with plenty of sunlight

Kelp Forests and Coral Reefs

Ocean Zones

• Open-Ocean Zone– Extends from the end of the Continental

Shelf to the next Continental Shelf– Surface zone

• Extends as far as the sunlight travels through the water.

• Can grow algae

– Transition Zone• Cold water with no light…extends from end

of surface zone to about 1km down

Ocean Zones

• Open-Ocean Zone

• Megalodon (6:14)

•Deep Sea Creatures

(5:15)

Questions

24. What are the three ocean zones that we have covered so far and what is a characteristic of each?

Ocean Zones

• Deep Zone– Pitch black area with no light and almost

freezing temps.– Few Organisms live in this zone!

• Hydrothermal Vents– Formed at divergent boundaries– Heat from magma under the ground shoots out

hot water and sulfur.• Tube worms and other creatures perform

chemosynthesis instead of photosynthesis!

• Observe Hydrothermal Vents

Ocean Resources

• Ocean Resources– Fish

• Tuna, Mahi Mahi, tilapia, anchovies, crabs• Observe Deadliest Catch

– Fuel• As fish die they sink and their remains decompose

and under pressure form oil and natural gas

– Water (Desalinization)– Minerals

• Magnesium, manganese, diamonds, gold

Questions

25. What are some characteristics of the deep zone?

26. What process helps life thrive on hydrothermal vents?

27. What are some resources we get from the ocean?

Project Earth

• Hungry Oceans– The aim of this experiment is to encourage

plankton growth by bringing cold water from the lower reaches of the ocean, to nearer the top. Cold, deep water contains important nutrients, and when this reaches the surface, it will then encourage the growth of phytoplankton. The team wants to find an efficient way to imitate natural plankton blooms — without dumping any chemicals into the water. 

– Episode Video: Hungry Oceans

Final Questions