Transcript Honors Marine Biology Class 2

Module 1
August 30, 2012
Class Challenge
Quiz
1. Identify all the Oceans
2. Identify all the Continents
3. Label where main the Mid-Ocean Ridges
are.
4. Label where the Ocean Trenches are.
The Motion of the Ocean
• The strongest motion in the ocean is at its
surface and is made up of surface currents
and waves.
• Ocean surface currents are in regions
where winds regularly blow over the ocean
in a reasonable constant direction and
velocity, pushing the water along.
• Surface currents, then, are large,
horizontal movements of water molecules
being pushed by the winds above them.
• The winds in our atmosphere result from
temperature differences caused by heat
from the sun.
• The heat is the strongest at the equator,
and weakest at the North and South poles.
• To understand wind patterns, consider
cold air near the surface of the earth at the
North Pole. The air will move from the
North Pole toward the equator, to even out
the temperature differences.
• As it makes its way there, however, it
encounters warmer climates. This warms
up the air, causing it to rise.
• When the air makes it to the 60 degree N
latitude, it becomes so warm that it rises
into the upper atmosphere and begins
moving back toward the North Pole.
• This sets up a loop of winds that travel
continuously from the Pole to a latitude of
about 60 degrees North and back again.
• Now look at the equator. We see the
exact opposite effect. As the warm air
rises, it starts traveling back to the poles.
• At a latitude of about 30 degrees North, it
cools down enough to sink and begin
traveling back toward the equator.
• From the equator there is also a loop of
winds that travel to a latitude of about 30
degrees North and then turn around and
come back again.
• In the middle of these two loops of wind
(between 30 degrees and 60 degrees)
there is a third loop that occurs as a
reaction to these two loops. These winds
are represented in brown in Figure 1.14 on
page 21.
Coriolis Effect
• The winds moving toward the equator
curve in a direction opposite of the rotation
of the earth.
• The way in which the rotation of the earth
bends the path of winds and resulting sea
currents
• Because of the Coriolis effect, these winds
bend west (opposite the rotation of the
earth) and approach the equator at a 45
degree angle.
These winds
Are called
Trade Winds.
Westerlies
• Farther away from the equator the winds
near the surface of the earth (between 30
degrees and 60 degrees) are bent
opposite the Trade Winds because they
are traveling away from the equator
instead of toward it.
• The Coriolis efffect causes them to bend in
the opposite way. These winds are called
Westerlies.
Polar Easterlies
The northernmost and southernmost winds
are called the polar easterlies and re the
most variable winds of all.
They curve in the same direction as the
Trade Winds, since they once again move
toward the equator near the surface of the
earth.
Currents
Currents
• Now all these major wind fields in the
atmosphere push against the ocean
surface and create currents.
• All the major currents of the open ocean
are driven by the wind.
• As the wind moves across the water it
forces the surface currents to move at a
45 degree angle from the wind direction.
Gyres
• Large, mostly circular systems of surface
currents driven by the wind.
• As water gets “pushed around” all over the
world, large surface currents result in a
circular pattern.
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Tides
Sarasota, Sarasota Bay, Florida
29 August 2012 - 31 August 2012
27.3317° N, 82.5450° W
2012-08-29 01:56 EDT 1.52 feet High Tide
2012-08-29 05:09 EDT Moonset
2012-08-29 05:45 EDT 1.23 feet Low Tide
2012-08-29 07:08 EDT Sunrise
2012-08-29 11:32 EDT 2.32 feet High Tide
2012-08-29 18:30 EDT Moonrise
2012-08-29 19:11 EDT 0.26 feet Low Tide
2012-08-29 19:53 EDT Sunset
2012-08-30 01:52 EDT 1.53 feet High Tide
2012-08-30 06:09 EDT Moonset
2012-08-30 06:35 EDT 1.04 feet Low Tide
2012-08-30 07:08 EDT Sunrise
2012-08-30 12:25 EDT 2.29 feet High Tide
2012-08-30 19:09 EDT Moonrise
2012-08-30 19:46 EDT 0.39 feet Low Tide
2012-08-30 19:52 EDT Sunset
Vertical Motion of the
Thermoclines: Experiment 1.A
Supplies:
• Fish Tank filled with water
• Pitcher of Cold water
• Food dye
Introduction:
• To observe the upturning of the water when
colder water is introduced to the tank.
Proceedure:
1. Fill tank with cold water ¾ full.
2. Add food dye to warm water.
3. Observe the water movement.
Observations:
Conclusion:
Homework
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Class Challenge
Study for Quiz on Currents
Read Module 1 Pages 20 – 28
Answer OYO Questions: 1.10 – 1.15
Answer Study Guide Questions:
define j – o and 10 – 17
• Complete Lab Book
• Take Module 1 Test