OceanographyOceanography

I. Major I. Major OceansOceans

• The three major oceans are: The three major oceans are: 1._______- largest, deepest, 1._______- largest, deepest, coldest, least salty. 2.__________- second coldest, least salty. 2.__________- second largest, shallow, warm, salty. largest, shallow, warm, salty. 3. _________- intermediate 3. _________- intermediate in depth, temperature, and salinity.in depth, temperature, and salinity.

• The _______Ocean near the North Pole, and the The _______Ocean near the North Pole, and the ____________ Ocean near the South Pole ____________ Ocean near the South Pole contain vast expanses of sea ice. contain vast expanses of sea ice.

PacificAtlantic

Indian

ArcticAntarctic

II. Methods of II. Methods of Studying the OceanStudying the Ocean

The Topex/Poseidon _____________ orbits 1331 km above the Earth, gathering information about the oceans.

_____________ maps ocean floor topography by timing how long it takes sound waves to bounce off the ocean floor.

Underwater vessels called _________________ investigate the deepest ocean trenches.

satellite

Sonar

submersibles

Sonar (also called echo-Sonar (also called echo-sounding)sounding)

• Sound waves travel Sound waves travel how fast in seawater?how fast in seawater?

• How deep is the How deep is the water if it takes ten water if it takes ten seconds for the sound seconds for the sound wave to go from ship wave to go from ship to ocean floor and to ocean floor and back to ship?back to ship?

1,454 m/s

7,270 m

Calculation: (10 s times 1,454 m/s divided by 2 )

• The picture below is of a _____________.The picture below is of a _____________.submersible

III. SalinityIII. SalinityThe amount of salt per unit water is known as salinity.

The average salinity of seawater is _____ ppt. Therefore, for every 1,000 ml water, there are ___ grams of dissolved salts.

The most abundant salt in seawater is ________, but there are many other salts present in the form of ions.

Near the equator salinity is __________ than average due to ___________________.

Near the poles salinity is __________ than average due to _______________.

In the Mediterranean the salinity is __________than average due to __________.

NaCl

3535

lowergreater precipitation lowermelting sea ice higher

evaporation

The salinity here would likely be:

A. 35 ppt

B. 34 ppt

C. 36 ppt

IV. Colorful SeawaterIV. Colorful Seawater

• What makes the ocean What makes the ocean water in the picture to water in the picture to the left different the left different colors?colors?

• Why would a shrimp Why would a shrimp that appears bright red that appears bright red at the surface appear at the surface appear black at greater black at greater depths, and why might depths, and why might this be beneficial?this be beneficial?

differences in depth

Longer (red) wavelengths are absorbed before reaching deep water. Shrimp can hide and not become a meal.

V. UpwellingV. Upwelling

upward motion of ocean watercold, nutrient-rich water is brought up to the surface

  El Niño – What is it?El Niño – What is it?

•Unusually warm temperatures in the equatorial Pacific•Occurs every 3-7 years•December and January

•trade winds relax or reverse direction (to blow from west to east) •reduced upwelling to cool the surface •warm surface waters from Indonesia move eastward•large central and eastern Pacific regions warm up

What causes What causes El Niño? El Niño?

•Fish off South America vanish - fishing business comes to standstill•Major disruption of normal global and local weather patterns

Impacts of El Niño?Impacts of El Niño?

Label the three ocean layers in the Label the three ocean layers in the diagram below:diagram below:

Surface layer

Thermocline

Bottom layer

Thermocline – sudden temperature Thermocline – sudden temperature drop not far from the surface.drop not far from the surface.

Label the wave diagram below with the following terms: wavelength, wave height, trough, crest

VI. Ocean MovementsVI. Ocean Movements

trough

crest

wavelength

waveheight

0

5

10

15

20

25

30

0 4 8 12 16 20 24

SemidiurnalMixedDiurnal

Tides

Label the key with the correct tide cycle names:

semidiurnalmixed

diurnal

Match the following terms to their correct letter in the diagram:

A

B

C

D

E

D

F

G

H

Island

Continental shelf

Continental slope

Abyssal plain

Seamount

Continental rise

Trench

Guyot

VII. Seafloor VII. Seafloor TopographyTopography

A.

B.

C.

D.

E.

F.

G.

H.

Listed below are some of the major surface currents. The force which generates these currents is ____________.wind

Turbidity Turbidity Current:Current:• A rapid, downhill flow of water A rapid, downhill flow of water

caused by increased density due caused by increased density due to high amounts of sediment.to high amounts of sediment.

Review1. What is the average salinity of seawater?

2. What is the deepest area of the seafloor?

3. What is the largest ocean?

4. Why is the ocean “blue”?

5. What is the force responsible for surface currents?

6. What causes density currents?

7. What causes tides?

8. List the 3 tidal patterns.

9. What is the highest part of a wave called?

10.Name the ocean that borders Virginia.

35 ppttrench

Pacific

shorter wavelengths not absorbed

wind

differences in temperature and salinity

gravity of the sun and moon

diurnal, semidiurnal, mixed

crest

Atlantic