Physical Oceanography
Chapter 15
Major Oceans
• The three major oceans are :
Pacific
1._______-largest,
deepest, coldest, least salty.
2.__________second largest, shallow, warm,
Atlantic
salty.
3. _________intermediate in depth,
Indian
temperature, and salinity.
Arctic
• The _______Ocean
near the north pole, and the
____________
Antarctic
Ocean near the south pole
contain vast expanses of sea ice.
Methods of Studying the Ocean
The Topex/Poseidon _____________
satellite
orbits 1331
km above the Earth, gathering information about
the oceans.
Sonar
_____________
maps ocean floor topography
by timing how long it takes sound waves to
bounce off the ocean floor.
submersibles
Underwater vessels called _________________
investigate the deepest ocean trenches.
Sonar (also called echo-sounding)
• Sound waves travel
how fast in seawater?
1,454 m/s
• How deep is the
water if it takes ten
seconds for the sound
wave to go from ship
to ocean floor and
back to ship? 7,270 m
Calculation: (10 s times 1,454 m/s divided by 2 )
submersible
• The picture below is of a _____________.
Salinity
The amount of salt per unit water is known as salinity.
NaCl
The most abundant salt in seawater is ________,
but
there are many other salts present in the form of ions.
The average salinity of seawater is _____
35 ppt. Therefore, for
every 1,000 ml water, there are ___
35 grams of dissolved salts.
Near the equator salinity is __________
lower
than average due to
greater precipitation
___________________.
lower
Near the poles salinity is __________
than average due to
melting sea ice
_______________.
higher
In the Mediterranean the salinity is __________than
average due to __________.
evaporation
The salinity
here would
likely be:
A. 35 ppt
B. 34 ppt
C. 36 ppt
Colorful Seawater
• What makes the ocean
water in the picture to
the left different colors?
•
differences in depth
Why would a shrimp that
appears bright red at the
surface appear black at
greater depths, and why
might this be beneficial?
Longer (red) wavelengths are
absorbed before reaching
deep water. Shrimp can hide
and not become a meal.
Label the three ocean layers in the diagram below.
Surface layer
Thermocline
Bottom layer
Ocean Movements
Label the wave diagram below with the following
terms: wavelength, waveheight, trough, crest
crest
trough
wavelength
waveheight
Tides
Label the key
with the
correct tide
cycle names:
30
25
20
Semidiurnal
semidiurnal
Mixed
mixed
Diurnal
diurnal
15
10
5
0
0
4
8
12
16
20
24
Seafloor Topography
H
A
Match the following terms to
their correct letter in the
diagram:
H.
Island
A.
Continental shelf
B.
Continental slope
D.
Abyssal plain
F.
Seamount
C.
Continental rise
G.
Trench
E.
Guyot
B
F
E
C
D
D
G
Listed below are some of the major surface currents. The force
wind
which generates these currents is ____________.
Chapter Review
1. What is the average salinity of seawater?
35 ppt
2. What is the deepest area of the seafloor?
trench
3. What is the largest ocean?
4. Why is the ocean “blue”?
Pacific
shorter wavelengths not absorbed
5. What is the force responsible for surface currents?
wind
differences in temperature and
6. What causes density currents? salinity
7. What causes tides?
gravity of the sun and moon
8. List the 3 tidal patterns.
diurnal, semidiurnal, mixed
9. What is the highest part of a wave called?
10. Name the ocean that borders Virginia.
crest
Atlantic