1. The Water Planet Ch. 22

2. What is Oceanography?
the study of the Earth’s oceans using chemistry, biology, geology, and physics.
Oceans cover 70% of the Earth’s surface

3. Ocean
Research
22.1
The use of submarines in World War II advanced ocean research with the invention of SONAR.

4. H.M.S Challenger 1872 first large-scale ocean research project
Measured:
Temperature
Depth
Took water samples
Observed currents

5. World War II Better ocean maps and charts Instruments: Sonar
Magnetic recorders

6. Modern Research (Technology)
Deep sea-corers take sediment samples
Sonar measures ocean depth
Deep sea cameras and lights, robotics, and advanced technology help explore the sea floor & take samples
buoys & satellites radio data back SST, sea level, & mov’mt

7. How do humans effect the oceans?
Think-Pair-Share:
How do humans effect the oceans?
List your ideas in your notes!!

8. Human Effects Oil spills Deep sea mining Pollution Dredging
Magnesium (Mg)
Table salt
Pollution
Dredging
Disturbs ocean floor
Global warming
Melts ice caps, changes salinity & sea level

9. The density of water is greater than its solid form, ice
Special Properties of Water
22.2
The density of water is greater than its solid form, ice

10. Density Density= mass ÷ volume (g/cm³)- it’s a ratio!
Density of fresh water= 1.0 g/cm³ (above freezing)
Density of ice= 0.92 g/cm³
Water expands as it freezes because of it’s shape!
ICE FLOATS!!!

11. Aqueous Solutions ocean is best example!
when any salt dissolves in water
as salt increases, density increases
change water’s: pH
density
boiling & freezing points

12. Ocean Water
22.3
Salinity and temperature are two characteristics of water masses that help scientists study oceans and their behavior.

13. Composition of Seawater
Ions in Seawater
Chloride
55.04%
Sodium
30.61%
Sulfate
7.68%
Magnesium
3.69%
All others
2.98%
Contains salts as dissolved ions
85% sodium chloride ions
more than 70 elements
some elements, such as calcium (Ca)--needed for marine life shells

14. Salinity measure of dissolved salts in water
units= parts per thousand (‰)
Ex: 1000 grams of seawater contains 35 grams of salt= 35 ‰
measured w/ hydrometer

15. Salinity
oceanographers calculate salinity by electrical conductivity of seawater
The higher the salinity, the stronger the electrical current
units= practical salinity units or psu
average seawater = 35 psu
Water Mass= body of water with distinct properties based on where it originates
salinity values used to help identify these

16. Variations in Salinity
LOW SALINITY AREAS
HIGH SALINITY AREAS
near rivers where fresh water enters
high precipitation near equators
sea ice melts
hot, dry climates w/ high evaporation rates
about 30º N & S (deserts)
near poles as water freezes
* SALINITY IS USUALLY AVERAGE (35‰) NEAR THE BOTTOM

17. Turn to the person next to you & Share:
What do you think the salinity of the ocean is like at the Equator? Why?!

18. Turn to the person behind you & Share :
What do you think the salinity of the ocean is like at the Poles? Why?!

19. Salt Enters & Leaves the Ocean
underwater volcanoes
erosion from rocks
marine organisms decompose
marine organisms use minerals for life
precipitate out of solution into sediment at floor
* Scientists believe the salinity of the ocean hasn’t changed in over 200 million years!

20. Temperature of the Ocean
heat from sun
temperature decreases w/ depth
Ocean divided into 3 temperature zones:
Mixed Layer or Epipelagic Zone
Thermocline
Deep zone

21. Epipelagic Zone or ‘Mixed Layer’
winds and currents mix heat evenly
most life lives here; only zone for plants
makes up 2% of ocean’s volume
can be m deep; in some spots 300m
temperature depends on latitude and season;
poles and equator mixed layer temperature is constant
Most oxygen- b/c of atmosphere & organisms (photosynthesis)
Oxygen decreases with depth

22. Creation of the Mixed Layer (surface)

23. Thermocline Temperature decreases rapidly throughout this zone
Little to no light
Varies most at mid-latitudes, not much variation at poles or Equator
Page 8 INB:
Which one belongs to the poles? The Equator? The mid-latitudes?
Talk with your neighbors!!!

24. Deep Zone No sunlight reaches seafloor- DARK!
Very little oxygen & life
Polar water masses are found at bottom because they are denser than other water and move around globe
Seafloor bottom = ~ 2° C

25. Water Mass Characterized based on where they originate
Body of water characterized by:
Salinity
temperature

26. How do water masses layer in the ocean? Why?
What do YOU think??
How do water masses layer in the ocean? Why?

27. Ocean Life
22.4
Scientists estimate that the oceans harbor as many as 10 million species!
Life forms range from microscopic organisms to the largest known animal, the blue whale.

28. Photosynthesis in the Ocean
takes place within mixed layer
Phytoplankton: microscopic single celled protists that float freely within ocean waters
take CO2 out of water and replace with oxygen
basis of food chain in ocean
Diatoms are examples with silica shells; deposited on seafloor when they die
Blooms- abundant phytoplankton populations; change color of seawater to green, yellow, or brown
Visible from space; scientists use to locate groups of life forms

29. Blooms are visible from space and help scientists track life forms.
Phytoplankton

30. Marine Animal Life
Zooplankton: microscopic animals that eat phytoplankton or smaller zooplankton
other animals eat zooplankton
can be larvae of larger animals s.a. squid, crab, jellyfish
moderate salinity by absorbing ions to make shells; back into water when they die
promote nutrient circulation as waste falls to bottom
Coral: tiny sea creatures that form reefs
lime from ocean creates shells; when they die new ones grow on old ones
prevent beach erosion b/c they stop waves along coasts
provide nutrients and shelter for larger organisms

31. Marine Animal Life (cont.)
Nektons: free-swimming organisms
include fish, whales, jellyfish
survival depends on temperature, salinity, and nutrient circulation
important food supply for other nektons and humans
overfishing, pollution, and trawling destroy populations & ecosystems

32. Deep Ocean Life no photosynthesis means no oxygen so CO2 accumulates
Hydrogen sulfide is primary source of energy
spewed out of deep sea vents and smokers
bacteria use chemosynthesis to produce food here
chemosynthetic bacteria are food for larger organisms
larger organisms thrive because of food & heat