Exploring the oceans ch 13
https://youtu.be/9NupRxTV38s
https://youtu.be/gj6frb_mHzQ
Objectives
1.
2.
3.
4.
List the major division of the global ocean
Describe the history of the Earth’s Oceans
Identify the properties of the ocean water
Describe the interactions between the ocean
& the atmosphere
I. Earth’s Oceans
A. Divisions of the Global Ocean
1. 71% of the Earth’s surface is covered with water
2. The Global ocean is divided by the continents
into 5 main oceans
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–
–
–
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Pacific= between Asia & Americas (largest)
Atlantic= 2nd largest
Indian
Artic= smallest
Southern= mostly ice
•
Antarctica to 60o S
3. Aunt Patty Seldom Ate Inchworms
B. How did the Oceans Form?
https://youtu.be/hwVU0-2Qnso
1. ~4.5 bill years ago there were no oceans
2. Volcanic gasses began to form a primitive
atmosphere & the Earth began to start cooling
3. ~4 bill years ago Earth cooled enough for water
vapor to condense into clouds & water fell as rain
which created our oceans
4. Pangaea= ~245 The
continents were 1 giant
land mass
5. ~180 mill years ago
Pangaea broke up into 2
large land masses
(Lauarsia & Gondwona)
6. ~65 mill years ago
continents continue to
spread
7. Today the continent move
at a rate of 1 – 10 cm per
year
https://youtu.be/cQVoSyVu9rk
–
Pacific ocean is getting
smaller & others are
getting larger
C. Characteristics of Ocean Water
1. Ocean water is salty
a. Contains sodium chloride (NaCl) = same as what we use on
food
b. Salts come from rivers and stream that flow into the oceans
today & bill of years ago
c. When water evaporates in the water cycle the salts stay
behind
2. Full of solids
a. Salinity= measure of the amount of dissolved salts in a given
amount of liquid
b. Measured in solids per kilogram of water
• If you evaporated 1000g of ocean water you would be left
with 35g of dissolved solids!
3. Climate effects salinity
http://aquarius.umaine.edu/cgi/ed_gallery.htm
a. Coastal waters along hotter drier
climates have a higher salinity
due to evaporation
b. Cooler more humid climates
have less evaporation, therefore
they have a lower salinity
4. Water movement affects
salinity
a. Slow moving areas bays, gulfs, &
seas & open ocean do m=not
have quick moving currents
creating a higher salinity
b. Fresh water inflow lessens the
salinity
5. Temperature zones: temp decreases with increasing
depths
a. Surface zone: warm top layer
•
•
300 m below sea level
Sun warms top 100 m
b. Thermocline: 2nd layer the extends from 300m – 700m below
sea level
•
c.
Temp drops faster than any other zone
Deep zone= from base of the thermocline to ocean floor
•
1o C – 3o C
6. Surface temperature
changes
a. Changes from time of year &
latitude
b. ~1o (32o F) near the poles to
~24oC (75o F) near the
equator depending on the
amount of sunlight