Transcript The Oceans - Effingham County Schools

Pacific Ocean
Pacific Ocean: The Pacific
Ocean is the biggest ocean of
the world and covers more than
30% of the Earth's surface. The
ring of fire is located in the
Pacific Ocean.
Atlantic Ocean
 Atlantic Ocean: The Atlantic is the second
biggest ocean in the world and is between the
continents of America and Europe and Africa.
The Atlantic Ocean is about half the size of the
Pacific Ocean and covers roughly 20% of the
Earth's surface. However it is growing in size as
it is spreading along the Mid-Atlantic Coasts.
The Mid-Atlantic Ridge is the longest mountain
range on Earth. It spreads from Iceland to
Antarctica beneath the Atlantic.
Indian Ocean
Indian Ocean: The Indian Ocean
is located between Africa,
Australia and Asia. The waters of
the Indian Ocean provide the
largest breeding grounds of the
world for humpback whales.
Arctic Ocean
Arctic Ocean: The Arctic Ocean is
located around the North Pole
across the Arctic Circle. There are
many polar bears living on the
Arctic ice.
Southern Ocean
Southern Ocean: The Southern
Ocean is located around the South
Pole across the Antarctic Circle in
the Southern Hemisphere off
Antarctica.
TIDES
Tides
 Tides are the daily rise (high tide) and
fall (low tide) of water along coastlines.
 Gravity and Tides: Tides are caused by the
gravitational interaction between the Earth, the moon
and, the sun. Gravity is the force where one object
pulls on another object.
 The pull of the moon on Earth’s waters causes a tidal
bulge on the side of the Earth facing moon. The
opposite side has the least amount of force pulling on
its water, so there is a bulge there as well.
 The Daily Tidal Cycle: The rotation of the Earth
through these bulges causes most coastlines to
experience two high tides and two low tides each day.
 The difference in water level between high tides and
low tides varies from place to place.
 The Monthly Tidal Cycle: The position of the
sun, moon, and Earth in relation to one another
affects tidal levels on a monthly basis.
 Spring tides occur during full and new moons, when
the sun, moon, and Earth are arranged in a straight
line.
 Spring tides have the largest difference between high
and low tides.
 Neap tides occur during first and third quarter
moons, when the sun, Earth, and moon are arranged
in a ninety degree angle to one another.
 Neap tides have the smallest difference between high
and low tides.
Regular Tide Description:
Pull of the moon on
Earth’s waters causes a
bulge on the side of the
Earth facing the moon
and the opposite side.
As long as it is not lined
up with the sun or at a
ninety degree angle it is
a regular tide.
Write a description for each tide and draw the positions of the
moon for a Spring Tide, Neap Tide and a Regular Tide.
Spring Tide Description:
occur during full and new
moons, when the sun, moon,
and Earth are arranged in a
straight line.
Earth
Description:
occur during first and third
quarter moons, when the
sun, Earth, and moon are
arranged in a ninety degree
angle to one another.
Earth
Neap Tide
Earth
Earth
Regular Tide Description:
pull of the moon on Earth’s waters
causes a bulge on the side of the Earth
facing the moon and the opposite
side. As long as it is not lined up with
the sun or at a ninety degree angle it
is regular.
Earth
Earth
Write a description for each tide and draw the positions of the
moon for a Spring Tide, Neap Tide and a Regular Tide.
Spring Tide Description:
occur during full and new
moons, when the sun, moon,
and Earth are arranged in a
straight line.
Earth
Description:
occur during first and third
quarter moons, when the
sun, Earth, and moon are
arranged in a ninety degree
angle to one another.
Earth
Neap Tide
Earth
Earth
Regular Tide Description:
pull of the moon on Earth’s waters
causes a bulge on the side of the Earth
facing the moon and the opposite
side. As long as it is not lined up with
the sun or at a ninety degree angle it
is regular.
Earth
Earth
Write a description for each tide and draw the positions of the
moon for a Spring Tide, Neap Tide and a Regular Tide.
Spring Tide Description:
occur during full and new
moons, when the sun, moon,
and Earth are arranged in a
straight line.
Earth
Description:
occur during first and third
quarter moons, when the
sun, Earth, and moon are
arranged in a ninety degree
angle to one another.
Earth
Neap Tide
Earth
Earth
Regular Tide Description:
pull of the moon on Earth’s waters
causes a bulge on the side of the Earth
facing the moon and the opposite
side. As long as it is not lined up with
the sun or at a ninety degree angle it
is regular.
Earth
Earth
Write a description for each tide and draw the positions of the
moon for a Spring Tide, Neap Tide and a Regular Tide.
Spring Tide Description:
occur during full and new
moons, when the sun, moon,
and Earth are arranged in a
straight line.
Description:
occur during first and third
quarter moons, when the
sun, Earth, and moon are
arranged in a ninety degree
angle to one another.
L
H
L
H
Earth
H
Earth
L
H
L
Neap Tide
H
H
L
L
Earth
L
Earth
L
H
H
Regular Tide Description:
pull of the moon on Earth’s waters
causes a bulge on the side of the Earth
facing the moon and the opposite
side. As long as it is not lined up with
the sun or at a ninety degree angle it
is regular.
H
L
L
L
H
Earth
Earth
H
L
H
 The driving energy source for heating of Earth and
circulation in Earth’s atmosphere comes from the Sun
and is known as solar energy. There are three ways
thermal energy can be transferred, radiation,
conduction and convection.
Radiation
 Radiation is the solar energy from the sun warms the
surface of the earth, however different materials heat
at different rates, which causes the earth’s surface to
heat unevenly. Uneven heating causes air to move.
Conduction
 As the surface of the earth is heated, it in turn heats
the air which is touching the earth’s surface. This type
of heat transfer is called conduction. Conduction is
heat transfer through direct contact.
Convection
 The warm air that touches the surface becomes
warmer, less dense and rises. This is the third type of
heat transfer known as convection. Convection is the
type of heat transfer that occurs with the movement of
liquids and gases through convection currents.
 Solar radiation warms Earth's surface.
 The ground warms the air that touches it through
conduction.
 Energy moves upward through convection as warm air is
pushed upward by cooler, denser air.
Winds
 Local Winds: Small-scale convection currents arise
from uneven heating on a small scale.
 This kind of heating occurs along a coast and in the
mountains.
 Local winds blow over a small area and change
direction and speed over a shorter period of time than
global winds.
 On a hot summer day at the
beach, the land heats up faster
than the water.
 The warmer air over land
becomes less dense (low
pressure) and rises; while the
cooler denser (high pressure)
air over the ocean rushes in to
take its place.
 This wind is called a sea, or
onshore, breeze.
 After sunset, the land cools
down faster than the water
and becomes denser (high
pressure).
 The warmer air, less dense
(low pressure) over the ocean
rises, while the cooler denser
(high pressure) air over land
rushes in to take its place.
 This wind is called a land, or
offshore, breeze.
 Global Winds: travel over
long distances from a
specific direction.
 Global winds are caused by
the unequal heating of
Earth’s surface. Air over the
equator is heated at a direct
angle from the Sun. This
causes the air at the equator
to heat up, become less
dense and have lower
pressure than the Polar
Regions.
 Global Convection
Currents: At the equator,
warm air becomes less dense
(has lower pressure) due to
heating and rises. At the
poles, cold air is denser (has
a higher pressure) and sinks.
This causes huge convection
currents.
 Winds at the surface tend to
blow from the poles to the
equator, while higher in the
atmosphere; the winds tend
to blow from the equator to
the poles.
Global Wind Belts
 Doldrums: This is an area of little wind at the
equator, because of warm temperatures.
Trade Winds:
 These winds
travel from
about 30o
latitude to the
equator.
Prevailing Westerlies:
 These winds travel
from about 30o latitude
to 60o latitude in the
Northern and Southern
Hemispheres.
Prevailing westerlies
play an important role
in our weather.
Polar Easterlies:
 These winds travel
from the poles to
60o latitude. The
mixing of cold and
warm air at this
latitude has a big
impact on our
weather
The Coriolis effect
 The Coriolis effect
 Is a result of Earth’s rotation
 Causes moving objects to follow curved
paths:
 In Northern Hemisphere, curvature is to
right
 In Southern Hemisphere, curvature is to
left
 Changes with latitude:
 No Coriolis effect at Equator
 Maximum Coriolis effect at poles
A merry-go-round as an example of
the Coriolis effect
 To an observer above the
merry-go-round, objects
travel straight
 To an observer on the
merry-go-round, objects
follow curved paths
 Internet video of balls
being rolled across a
moving merry-go-round
Figure 6-8
The Coriolis effect on Earth
 As Earth rotates,
different latitudes
travel at different
speeds
 The change in speed
with latitude causes
the Coriolis effect
Figure 6-9a
Missile paths demonstrate the
Coriolis effect
 Two missiles are fired
toward a target in the
Northern Hemisphere
 Both missiles curve to
the right
Figure 6-9b
Ocean Currents
 An Ocean Current is a large volume of water flowing in
a certain direction.
Surface Currents
 Wind-driven currents are called surface currents.
Surface currents carry warm or cold water horizontally
across the ocean’s surface. Surface currents extend to
about 400 m below the surface, and they move as fast as
100 km/day.
Prevailing winds
 Earth’s major wind belts, called prevailing winds,
influence the formation of ocean currents and the
direction they move.
Density Currents:
 Density current is a type of
vertical current that
carries water from the
surface to deeper parts of
the ocean.
 Density Currents are
caused by changes in
density rather than wind.
 Density currents circulate
thermal energy, nutrients
and gases.
Climates
 Warm-water currents and cold-water currents affect
weather and climate in different ways.
 Regions near warm-water currents are often warmer
and wetter than regions near cold-water currents.
Examples
 The Gulf Stream is a warm-water current that affects
coastal areas of the southeastern United States by
transferring lots of thermal energy and moisture to the
surrounding air. The greatest impact the Gulf Stream
has on climate is found in Europe. It helps keep places
like Ireland and England much warmer than they
would otherwise be at such high latitude.
Examples
 The cold
California
Current affects
coastal areas of
the
southwestern
United States.
Waves
 A wave is a way in which energy travels from one place
to another. There are many kinds of waves, such as
water waves, sound waves, light waves, radio waves,
microwaves and earthquake waves.
Waves
 The highest point the wave reaches is called the crest.
The lowest point is called the trough. The distance
from one crest to the next is the wave length. The
number of waves that pass a given point in one second
is the wave's frequency.
 When wind blows over the ocean's surface, it creates
waves. Their size depends on how far, how fast and
how long the wind blows.
 A brief, gentle breeze forms patches of tiny ripples on
the surface; strong, steady winds over long distances
create large waves. But even when you feel no wind at
all, you may encounter large swells created by distant
storms.
 In the open sea, waves make floating boats bob up and
down instead of pushing them along. This is because
the waves travel through water; they do not take the
water with them. As a wave arrives it lifts water
particles. These travel forward, then down and back so
that each particle completes a circle. Circling
movements of particles near the surface set off smaller
circling movements below them.
Fill in the LHA on Waves page 141
1.
4
5.
.
3
.
2.
1. Crest
Wave
Length
4.
5. Wave
Height
Rest Position or
Still water level
3.
2. Trough