Oceanography
Intro to Earth
• Video introduction to the formation of the
solar system.
Oceanography
• Interesting general
stuff:
1. Oceans cover
70.8% of the earths
surface.
2. Oceans contain
97% of earth’s life.
3. Oceans contain
97% of earth’s water.
Oceanography
4. Oceans greatly
affect earth’s
weather.
5. Oceans release
between 50-85%
of earth’s oxygen
6. Ocean’s absorb
around 50% of
atmospheric
carbon dioxide.
Oceanography
7. Ocean’s produce
a huge percentage
(difficult to
calculate) of human
food sources.
8. Approximately
80% of the human
population live on
or within one hour’s
drive of the ocean.
Oceanography
Oceanography
“We should explore and take care of the ocean
as if our very lives depended on it. Because
they do.”
Dr. Sylvia A. Earle
Oceanography
I. How many oceans on earth – 4 principal
oceans plus one.
A. Pacific Ocean - My personal favorite
Ocean
1. Largest ocean in size (Over 50% of the
worlds total ocean surface area).
Oceanography
2. Covers about
1/3 of the
earth’s
surface.
3. Worlds deepest
ocean.
4. Has killer
surfing.
Oceanography
B. Atlantic Ocean
1. Lies between
the East coast of
the American
continent and the
West coast of
the “Old world”
continent.
Oceanography
2. The Atlantic
Ocean is about
½ the size of
the Pacific.
3. Named after
Atlas (Greek
Titan).
Oceanography
C. Indian Ocean
1. Slightly
smaller than
the Atlantic.
2. Mostly in
Southern
hemisphere.
Oceanography
D. Arctic Ocean
1. Only 7% of the
size of the Pacific.
2. Has permanent
layer of Sea-Ice.
Oceanography
3. Named after
Ursa Major (big
dipper)
-Arktos = bear
Oceanography
E. Southern Ocean
(Antarctic Ocean)
1. Near Antarctica
2. Defined by
currents
3. S. of 50 degrees
south latitude.
Oceanography
F. Comparing Oceans to Continents.
Changing oceans video
1. Oceans
a. Average depth of the ocean is 12,000 ft.
b. The Mariana Trench logs as the deepest
point in the Ocean (36,000 ft below sea
level).
c. Contains the tallest mountain in the
world (Mauna Kea) at 31,601 ft.
Oceanography
d. The magnetic
pattern on the seafloor
is symmetrical about,
and parallel to midoceanic ridges.
- Due to new rock
formation at ridge.
Oceanography
e. New seafloor
forms at the midAtlantic ridge.
** This means
the seafloor
increases in age
from the ridge
outward.
Oceanography
2. Continents
a. Average
height above sea
level = 2756 ft.
b. Tallest land
mountain (Mt.
Everest) is
29,035 ft in
height.
Oceanography
c. The continents are slowly
moving away from one
another = Continental
Drift.
- Alfred Wegener
theorized that aprox. 200
million years ago there
was one supercontinent
called Pangea.
Oceanography
II. History of Ocean exploration
A. Early history
1. Pacific Navigators did not leave a clear
written account.
-Earliest proposed sea migration (New
Guinea to New Ireland) about 4000BC.
Oceanography
-Evidence (Pottery) of
further migration at
about 1100BC.
- Ancestral Hawaiians
probably reached Hawaii
around 300AD.
-Polynesians then
reached Easter Island
around 1200AD.
Oceanography
2. European Navigators- Did a little boating as
well.
a. Phoenicians – From the Fertile Crescent.
-Explored Indian ocean around 2000BC
- Also circumnavigated Africa in 590BC.
Oceanography
B. Middle Ages – Vikings
-Leif Eriksson was the first to land in the
Americas in 995 AD (Newfoundland
Canada).
-Due to bad luck and bad weather Viking
colonies in Newfoundland died out by
1490.
Oceanography
C. The Age of Discovery1492 – 1522 – Europe –
fueled by the need for
a new Eastern Trade
Route (Money).
Oceanography
1. Christopher
Columbus – 1492
Financed by Spain to
find a new route to
East Indies.
• - When he
landed in the
Bahamas he
thought they
had made it to
Asia.
Oceanography
2. Ferdinand Magellan
– 1519 – Spain
-Initiated the first
circumnavigation of
the globe.
Oceanography
-Sadly, he was killed in a fight with Philippine
natives on March 15, 1521.
-Began with 5 ships and 280 Sailors
-3 years later (1522) 1 ship and 18 men completed
the voyage.
D. Beginning of Scientific
Voyaging–
1. James Cook
(England) made 3
scientific voyages
between 1768 & 1779.
a. Mapped a great
deal of the ocean.
b. Determined the
outline of the
Pacific.
c. Discovered
Sauerkraut
prevents scurvy.
d. Killed in Hawaii
by Natives.
Tides
Tides
• What are tides?
• How does a tide
differ from most
waves?
• What is the simple
explanation for
the forces that
cause tides?
• What is the center of mass of the Earth-moon
system called? So, does the moon really revolve
around the earth?
• What is a Centripetal Force? If this force,
relating to the earth and sun, were to stop, in
which direction would the earth move in
relation to its current orbit?
• When the moon is directly overhead and
therefore at 90° from your horizon, it is at its Z
point. What does Z stand for? Is the
gravitational pull of the moon stronger at the Z
point or Nadir point? Why?
• Which is longer, a day on the moon (lunar day)
or a day on earth?
• What is the term for the difference between
low and high tide in vertical height?
• What is the difference between a neap and a
spring tide?
• How often do neap and spring tides occur?
• What causes a neap tide?
• What causes a spring tide?
• Considering the distance from the moon,
during which period will changes in tides
(from low to high) be the most dramatic?
Why?
• What is the difference between a diurnal and
a semidiurnal tidal pattern?
• What is a mixed tide pattern and where in the
US would one experience such a pattern?