Transcript Aquatic Science

Travis High School
Aquatic Science
• Unit 1 – An Introduction
World Ocean
• All oceans of the world are connected.
• Could a ship attempting to travel through
all oceans do so without being stopped?
– What about ice?
• The waters beneath the ice do connect the
ocean basins.
Ocean Basins
World’s Ocean is divided into 4 major ocean
basins:
1. Arctic
2. Atlantic
3. Indian
4. Pacific
There are no natural boundaries that entirely
separate the 4 ocean basins.
1955 – The United Nations established the
boundaries of the oceans and continents.
Aquatic Science
Unit I, Section 1
Oceans and Continents
Arctic Ocean (Northern Ocean)
 Smallest
 Includes waters north of
the North American and
Eurasian continents.
 It is bounded from the
Pacific by the Bering Strait
and from the Atlantic at
about the 650 latitude (just
north of Iceland).
 The central part of the
ocean is permanently
covered in about
10 feet of ice.
Atlantic Ocean
 2nd largest and youngest
 Connects the polar ocean
waters
 Located between the
continents of North and South
America, Europe, Africa and
Antarctica.
 Covers about 20% of the
Earth's surface
 Busiest shipping ocean
 Crude oil and natural gas
Indian Ocean
 3rd largest ocean
It is surrounded by southern Asia, the Arabian Peninsula,
Africa, the Malay Peninsula, the Sunda Islands,
Australia and Antartica.
 Trade route between Africa and Asia!
 Petroleum extracted from Persian Gulf
Pacific Ocean
 Largest
Covers approximately
one-third of the earth’s surface
 More surface area than all
the continents combined!
 The tallest mountain in the
world is found in the Pacific
Ocean: Mauna Kea of the
Hawaiian Islands.
 Earthquakes and Tsunamis
common
Seas
The term sea is a term of tradition and is
not used consistently.
Some seas are enclosed lakes.
(Caspian Sea and Sea of Galilee)
Some seas are partially enclosed or isolated
from other sections of ocean.
(Mediterranean Sea and North Sea)
“The Seven Seas” and “the South Seas” are
terms of ancient times or of literature and
not places on maps and charts.
Seas as Enclosed Lakes
Partially Enclosed Seas
Continents
Large land masses
There are 6 major continental land areas:
1.
2.
3.
4.
5.
6.
Africa
Antarctica
Australia
Eurasia
North America
South America
The 1955 United Nations agreement divided
the landmasses according to political
boundaries.
Africa – continent bordered to the north by
the Mediterranean Sea, to the west by the
Atlantic Ocean, to the east by the Red
Sea and the Suez Canal, and to the eastsouthwest by the Indian Ocean
Antarctica – continent of the South Pole
Australia – smallest of the continents – It is
located between the Indian and Pacific
Oceans.
Eurasia – a single continuous landmass that includes
Europe and Asia – Asia includes Saudi Arabia and
on political maps also includes Japan, Taiwan,
Indonesia and the Philippines. Europe is separated
from Asia by political boundaries set from the
Caspian Sea north along the Ural Mountains to the
Kara Sea.
North America – includes Canada, U.S., Mexico and
Central America down to Panama. Islands in the
Arctic Ocean are included in North America on
political maps.
South America – includes all the countries south of
Panama
 Ice covers 10% of the total surface of the
Earth.
4.5% is on land
 the remaining 5.5% is on the ocean’s
surface
Section 2 – Maps
Globes, since the earth is spherical,
represent its surface features more
accurately than any map.
Cartographers (map makers) today can make
very detailed and accurate maps of the
earth using photographs from satellites and
much improved data collected on earth.
• Maps give a two-dimensional representation
to a three-dimensional object. Even
flattening the carved surface of a sphere
onto a 2-dimensional surface changes the
way it looks.
Types of Maps
Three types of maps are used in the study of
continents and ocean basins:
1. Homolosine maps – (refer to figure 1-1 on
page 2) distorts the continents as little as
possible.
2. equal-area maps – (refer to fig 2-1 page 8)
appear as if globes were cut apart but each
has an equal area
3. cylindrical projection map – (refer to fig 22 page 8) to get a “full” map the ends
would be connected (most maps used in the
classroom)
Section 3 Locating Points on a Globe
There are two types of reference lines used
to make accurate maps and to locate
points or positions on globe, map or chart
of the earth.
They are:
1. Parallels of latitude
2. Meridians of longitude
The primary reference lines are:
a. The equator (latitude)
b. The prime meridian (longitude)
The Equator, Hemisphere, Axis, and
Directions
The Equator is a reference line drawn around
the earth halfway between the north and
south poles.
The earth rotates daily around the axis.
The north and south poles are the points
where the axis enters and exits.
The Northern Hemisphere is the half of the
earth north of the equator.
What continents are in the Northern
hemisphere?
The Southern Hemisphere is the half of the
earth south of the equator.
What continents are in the Southern
hemisphere?
*hemi = half
Parallels of latitude
Latitude is the distance measured in degrees
from 00 to 900 north and south of the
equator.
Parallels of latitude are imaginary reference
lines that form complete circles around the
earth parallel to the equator and each
other.
Every point on a parallel is the same distance
from the equator.
Degrees of latitude are measured from an
imaginary point at the center of the earth.
Except for positions located right on the
equator (00), degrees latitude are always
labeled to tell whether they are north or
south of the equator.
Examples:
Honolulu, Hawaii is on the 210 North Parallel.
Sydney, Australia is located on the 340 South
parallel.
Longitude
Distance east and west of the Prime Meridian
is measured in degrees from 00 to 1800.
All meridians of longitude are given in
degrees east or west of the Prime
Meridian.
Meridians of longitude are imaginary lines
forming half circles passing from the North
Pole to the South Pole.
The Prime Meridian (00), by international
agreement is drawn through Greenwich,
England.
Examples:
Washington, D.C. is on the 770 West
Meridian.
Rome, Italy is on the 120 East Meridian.
The International Date Line
The International Date Line is an imaginary
line running mostly along the 1800 meridian.
Events immediately right or left of the date
line are 24 hours apart.
The International Date Line was adjusted to
allow certain land masses to remain
together in the same day.
Location
Lines of latitude and longitude form a global grid
system.
Any point on the globe can be located by specifying
its latitude and longitude.
So that a point can be located more exactly, degrees
are subdivided into minutes and minutes into
seconds. (Minutes and seconds do not refer to
time, but to parts of degrees of an angle.
10 = 60 minutes (60’)
1 minute = 60 seconds (60”)
Distance measured by marine and air
navigators is in Nautical Miles.
1 nautical mile = 1.85 km (1.15 miles)
(1 nautical mile – 1 minute of an arc
measured along a meridian of longitude.)
1 knot – 1 nautical mile per hour