Post on 28-Jun-2020
11/22/2016
ES Ch 15 Oceanography 1
11/22/2016 ES Ch 15 Oceanography
1
Chap 15 Oceanography Objectives 1. Identify methods used by scientists to study Earth’s oceans. This means I can
explain how sonar works and is used to calculate the depth of the oceans.
2. Discuss the origin and composition of the oceans according to scientific theory. This means I can:
A. Contrast the two main theories on where water on the earth may have come from.
3. Describe the distribution of oceans and major seas. This means I can:
A. List the 3 largest oceans in order by size.
B. Contrast and compare oceans and seas.
C. Explain how warm (interglacial, global warming) and cool (ice ages) affect sea level.
4. Compare and contrast the physical and chemical properties of seawater. This means I can:
A. List the percentage salt water and fresh water on earth, and where most of the fresh water is located.
B. Explain how evaporation, precipitation, freezing, melting and river discharge affect the salinity and density of water.
C. Describe how temperature and salinity affect density.
D. Explain how salinity affects the freezing point of water.
E. Describe means that remove and add salt from the ocean (See Figure 15-13 p.395)
5. Explain ocean layering (surface, bottom, thermocline). This means I can:
A. List the layers of the ocean in order from top to bottom.
B. Describe which layers are present at the equator, 30oN & S, and the poles.
11/22/2016
ES Ch 15 Oceanography 2
Objectives 6. Describe the formation of the 3-main deep-water masses: Antarctic Bottom Water,
Antarctic Intermediate Water, North Atlantic Deep Water. (Fig 15-17 p. 398) I can:
A. List their order from bottom to top at the equator.
B. Contrast their density and temperature.
C. Explain causes the density differences in the 3 deep-water masses. 7. Describe the physical properties of waves. This means I can:
A. Define/label the following terms: crest trough, wave length, wave height, wave.
B. Describe what causes breakers to form.
8. Explain how tides form. This means I can differentiate between spring & neap tides (Figure 15-22 p.403) including:
A. Alignment of sun, earth and moon, moon phase.
B. Size of low and high tides.
9. Compare and contrast various ocean currents. This means I can:
A. Differentiate cold vs. warm currents based on where they originate.
B. Define gyre. (Figure 15-23 p.404)
C. Understand the effect of global wind systems on currents and how the currents would change if the wind blew in the opposite direction.
10. Compare and contrast the effects of ocean currents during normal and El Nino winters on climate. This means I can:
A. Describe the climate changes of NW South America, the United States and
Australia during an El Nino season.
B. I can explain how changes in wind and ocean currents causes the climate changes
11. Additional miscellaneous vocabulary terms I can define and use properly: tidal
range, breakers, upwelling, oceanography, surface current, density current, fetch.
11/22/2016 ES Ch 15 Oceanography
3
Chapter 15 - Oceanography
11/22/2016 ES Ch 15 Oceanography
4
Intro – Are Oceans Distributed Equally Throughout Earth?
11/22/2016 ES Ch 15 Oceanography
5
Water Distribution 1. 97% of Earth’s water is saltwater in oceans and seas
2. 3% freshwater, but ¾ of the freshwater is unavailable since it is in
glaciers & icebergs (Greenland & Antarctica)
3. Sea level varies due to
A. Warming & cooling periods with ice varying from 0-10% of the
hydrosphere
B. Currently rising 1-2mm/year as glaciers melt
i. Melting of GLACIERS DOES affect sea level
ii. Melting of ice bergs does NOT influence as much.
C. Tectonic forces also lift or lower portions of the sea floor
D. NOTE: All seas and oceans are interconnected, so sea level rises
or falls in ALL oceans at the same time
11/22/2016 ES Ch 15 Oceanography
6
What might happen if sea levels continue to rise?
http://www.planetsave.com/files/2007/12/two-meter-sea-level-rise.gif
11/22/2016
ES Ch 15 Oceanography 2
11/22/2016 ES Ch 15 Oceanography
7
The Blue Planet-Ocean Size & Fig 15-5 p.389
1. 71% of Earth is covered by oceans, but they are not distributed evenly
A. There is more ocean in the Southern hemisphere
B. There is more land in the Northern hemisphere
2. 3 major oceans: Pacific (largest), Atlantic (2nd), and Indian (3rd)
11/22/2016 ES Ch 15 Oceanography
8
Fig 15-6 Northern vs. Southern Hemisphere Water
11/22/2016 ES Ch 15 Oceanography
9
11/22/2016 ES Ch 15 Oceanography
10
Sea Ice: The Arctic and Antarctic are covered with sea ice
NOTE: Frozen water is UNUSUAL. Solid water (ice) is LESS dense so it floats.
Otherwise bodies of water would freeze from bottom up until ALL frozen.
Since it floats it acts as an insulator and organisms live in cold water
beneath it.
Native American discusses sea ice melting & effect on way of life – 2 minutes
https://www.youtube.com/watch?v=u5DiHp76gjs
OR watch downloaded video saved as “Video “Sea Ice Native American”
11/22/2016 ES Ch 15 Oceanography
11
Seas: Seas: are smaller then oceans and are partly or mostly
landlocked
NOTE: All seas & oceans are connected, so they have similar types of dissolved salts AND the same sea level.
11/22/2016 ES Ch 15 Oceanography
12
Salinity • Prior Knowledge: What is “saline”?
Salinity: Measure of amount of dissolved salts in seawater
1. Seawater is 95% water & 3.5% salts
2. NaCl is the most common salt. Other salts contain
Mg, K, Ca.
3. Units: parts per thousand, ppt, which is the number
of grams of salt per kilogram (1000grams) of water
A. Sea water salt content is 35 ppt or 3.5%
4. Seawater also contains dissolved gases & nutrients
11/22/2016
ES Ch 15 Oceanography 3
11/22/2016 ES Ch 15 Oceanography
13
Variations in Salinity 5. Salinity varies due to
A. Evaporation exceeds precipitation. Leads to increased salinity. (Subtropical areas 30oN&S – hot and not much rain)
B. Abundant precipitation decreases salinity. (Tropical areas near equator – even though hot, have LOTS of rain which dilutes & lowers salinity)
C. Decreased salinity where rivers empty into oceans
11/22/2016 ES Ch 15 Oceanography
14
Sources of Salt 6. Sea Salt Sources (Addition)
A. Volcanic gases contain chlorine & sulfur dioxide which
dissolve in water to form ions
B. Weathering of crustal rock carries sodium, calcium,
potassium into rivers and on to oceans
This diagram in
notes after
addition,
removal &
desalinization
11/22/2016 ES Ch 15 Oceanography
15
Removal of Sea Salts 7. Sea Salt Removal
A. Sea salts precipitate out (become solid) in arid, coastal regions leaving salt deposits
B. Spray droplets from waves are carried by wind inland
C. Marine organisms use salts to build shells, bones, etc.
8. NOTE: Salinity remains relatively constant as addition (sources of salt) are balanced by these removal processes
11/22/2016 ES Ch 15 Oceanography
16
Fig 15-13 p. 395 & TT # 44
Processes that Add & Remove Salts
11/22/2016 ES Ch 15 Oceanography
17
Desalinization
8. Desalinization: Human removal of salt to obtain
fresh water for drinking
A. Methods: distillation, reverse osmosis
11/22/2016 ES Ch 15 Oceanography
18
Physical Properties of Seawater Physical Properties of Seawater
1. Higher density than freshwater, because of salt content.
2. Temperature also affects density
3. Why do we salt roads in the winter?
• The freezing point of seawater is lower (-2oC) compared to freshwater which freezes at is (0oC )
• Note: -2C = 28F
4. Water absorbs light, so water is darker with depth
11/22/2016
ES Ch 15 Oceanography 4
11/22/2016 ES Ch 15 Oceanography
19
Ocean Layering 1. Surface temps vary from –2oC (28F) in polar water to 30oC
(86F) near the equator
A. Temp decreases with depth
2. Temperature profile; 3 layers
3. Surface Layer: Relatively warm and sunlit
A. Thermocline: Rapid temperature change
B. Bottom Layer: Cold & dark
C. NOTE: The surface and thermocline layers are absent
in polar waters.
WHY??_____________
11/22/2016 ES Ch 15 Oceanography
20
Fig 15-15 & 15-16 Ocean Layers & Temps
11/22/2016 ES Ch 15 Oceanography
21
Fig 15-18 p. 399 Waves
NOTE: Energy, not water
molecules, are
moved/pushed.
Example: Make a
“wave” like at a game.
11/22/2016 ES Ch 15 Oceanography
22
Wave Diagram-compared to still water level
11/22/2016 ES Ch 15 Oceanography
23 11/22/2016 ES Ch 15 Oceanography
24
Tides:
Tides are periodic rise and fall of sea level
1.Caused by the gravitational attraction between Earth,
moon & sun
2.Moon’s gravity causes Earth to bulge
Lunar Bulge follows moon http://oceanservice.noaa.gov/education/kits/tides/media/supp_tide04.html
11/22/2016
ES Ch 15 Oceanography 5
Spring vs. Neap Diagram
11/22/2016 ES Ch 15 Oceanography
25 11/22/2016 ES Ch 15 Oceanography
26
Drawing comparing water levels of spring, neap &
average tide levels
11/22/2016 ES Ch 15 Oceanography
27
Animation – Spring & Neap Tides
Other animations: http://ww2.valdosta.edu/~cbarnbau/astro_demos/tides/neap_sp.html
http://ww2.valdosta.edu/~cbarnbau/astro_demos/tides/neap_sp.html
11/22/2016 ES Ch 15 Oceanography
28 11/22/2016 ES Ch 15 Oceanography
29
Fig 15-17 p. 398 Water Masses/Density Currents
From Weather Unit define: Air Mass, Source Region
Before notes, use the diagram above and determine:
Which deep-water mass has temps below 0C?
1. Which deep-water mass is the least dense? How can you tell?
2. Which deep-water mass forms off the shore of Greenland?
How do you know?
11/22/2016 ES Ch 15 Oceanography
30
Water Masses 1. Cold (almost freezing), bottom layer in the tropics comes from polar
regions.
A. Freezing water at the poles, leaves salt behind
B. Salt builds up below the ice
C. Cold, salty water is more dense and sinks
D. Concentrated salt water diffuses (moves) as the water mass
moves along the ocean floor towards the equator
2. 3 major water masses account for most of the deep water in the
Atlantic:
A. Antarctic Bottom
(coldest)
B. North Atlantic Deep
C. Antarctic Intermediate
Water (Warmest)
1. Cold (almost freezing), bottom layer in the tropics comes from polar
regions.
A. Freezing water at the poles, leaves salt behind
B. Salt builds up below the ice
C. Cold, salty water is more dense and sinks
D. Concentrated salt water diffuses (moves) as the water mass
moves along the ocean floor towards the equator
2. 3 major water masses account for most of the deep water in the
Atlantic:
A. Antarctic Bottom
(coldest)
B. North Atlantic Deep
C. Antarctic Intermediate
Water (Warmest)
11/22/2016
ES Ch 15 Oceanography 6
11/22/2016 ES Ch 15 Oceanography
31
Density Currents
Density Current: Current caused by a difference in temp &
salinity
1. Current moves slowly in deep waters
2. The 3 deep water masses are density currents
because they move from their source region in the
poles toward the equator.
11/22/2016 ES Ch 15 Oceanography
32
Gyres
1. Landmasses deflect ocean currents to north or south
A. Prevent global belts of easterly or westerly ocean
currents
2. Gyre = Closed, circular currents
11/22/2016 ES Ch 15 Oceanography
33
Gyres cont’d & Upwelling
3. 5 main gyres: North Pacific, North Atlantic, South Pacific,
South Atlantic, & Indian Ocean
4. Coriolis effect
A. Gyres in the Northern hemisphere rotate clockwise
B. Gyres in the Southern hemisphere rotate counter-
clockwise
11/22/2016 ES Ch 15 Oceanography
34
Fig 15-24 p. 405 Upwelling
Upwelling: Upward motion of ocean water
1. Cold because it originates at the bottom of the
ocean
2. Usually occurs on the west coast of continents in the
area of trade winds
3. Rich in nutrients, supports abundant marine life
A. Good fishing off of Peru & California
11/22/2016 ES Ch 15 Oceanography
35
Fig 15-23 p. 404 Major Ocean Currents
Message in a Bottle: If a bottle was dropped in the Atlantic
by Florida, list 3 locations it might end up. Test it out at:
http://serc.carleton.edu/details/images/19052.html
Currents: Warm vs. Cold
11/22/2016 ES Ch 15 Oceanography
36
http://www.sailingissues.com/currents1.png Ocean Current Temp Review: Use the diagram above, or on page 404, to complete the table:
Current Circle which direction the current COMES FROM
Circle whether the current is relatively warm or cold
Kuroshio Current Comes from: Poles vs. Equator Warm vs. Cold
E. Australian Current Comes from: Poles vs. Equator Warm vs. Cold
Gulf Stream Comes from: Poles vs. Equator Warm vs. Cold
Brazil Current Comes from: Poles vs. Equator Warm vs. Cold
California Current Comes from: Poles vs. Equator Warm vs. Cold
Peru Current Comes from: Poles vs. Equator Warm vs. Cold
Canary Current Comes from: Poles vs. Equator Warm vs. Cold
Benguela Current Comes from: Poles vs. Equator Warm vs. Cold
11/22/2016
ES Ch 15 Oceanography 7
11/22/2016 ES Ch 15 Oceanography
37
Bellwork #1: Earth’s Water
1. What percent of Earth’s water is salt water?
2. Where is most of Earth’s freshwater located?
3. What region of Earth contains the most water?
Northern Hemisphere or Southern Hemisphere?
11/22/2016 ES Ch 15 Oceanography
38
Bellwork #2 Adding & Removing Salt, Thermocline
1. What are two natural processes that remove sea salt and
decrease ocean salinity?
2. What are two methods responsible for adding salt back into
the ocean?
3. Draw the temperature profile found in the ocean and label
each of the three layers with the appropriate name.
11/22/2016 ES Ch 15 Oceanography
39
Bellwork #3 Wave height, Melting, Cold Water Mass
1. What is a factor that causes wave height to increase
(List as many as you can think of)?
2. If water melts at the poles, how is ocean salinity
affected?
3. Name the coldest water mass at 0o latitude.
11/22/2016 ES Ch 15 Oceanography
40
Bellwork #4 Parts of Waves
1. Explain what happens to water when waves move
through it?
2. Label the parts of the wave labeled A, B, C, D.
11/22/2016 ES Ch 15 Oceanography
41
Bellwork #5 Tides
1. What needs to happen for high tides to occur? Low
tides?
2. How often do you see high tides? Low tides?
3. Draw the alignment of the Sun, Earth, and Moon
needed to produce a spring tide and a neap tide.
4. What makes a spring tide different from other tides?
11/22/2016 ES Ch 15 Oceanography
42
Bellwork #6 Currents
3. Use the Major Ocean
Currents Diagram: If the
trade winds blew from
the west to the east
instead, what effect
would that have on the S.
Equatorial Current?
1. What is the name of circular currents between the
continents?
2. What has high salinity and moves slowly in deep water?
11/22/2016
ES Ch 15 Oceanography 8
11/22/2016 ES Ch 15 Oceanography
43
Lab Ocean Tides & Tidal Ranges KEY