Download Chapter 1 notes - Freedom Area School District

The Earth
Vocabulary and key points
Equator - an imaginary line that marks the midpoint between the North pole and the South pole.
There are 7 continents on the earth: Africa, Asia, Antarctica, Australia, Europe, North America,
and South America
The planet is ever moving. For example, Hawaii is moving 2in. closer to Japan every year and
Australia is moving 4 in. closer to New Zealand every year.
Earth has 4 layers.
Crust - the top layer of rock on the earth
Mantle- 2nd layer made up of melted rock called magma
Outer core
Inner core
Rotation of the earth on its axis causes day and night
Revolution of the earth around the sun causes the length of night and day to vary, the revolution
of the earth also causes the 4 seasons
Orbit - the path the earth follows as it revolves around the sun
Equinox - occurs when the direct rays from the sun hit the equator; results in equal day and
night. (March 21 and Sep. 21)
Latitudes (also called parallels)- imaginary lines north and south of the equator
Low latitudes (tropics)- latitudes between tropic of cancer and the tropic of capricorn
Middle latitudes (temperate regions)- between the tropic of cancer and the arctic circle
and between the tropic of capricorn and the antarctic circle
High latitudes (polar regions)- north of the arctic circle and south of
the antarctic
circle
* the lower the latitude, the more sun that area gets
Longitude (also called meridians)- imaginary lines that circle the earth running through the
North and South poles. Prime Meridian is the starting point for longitude and is labeled 0
longitude
Map projections - trying to represent the round earth on a flat surface
cylindrical projection (Mercator)- this type of projection allows for strait line navigation
(important in the 1500's), but it enlarges the areas in the high latitudes
Robinson map is the projection the National Geographic Society has adapted for its maps
computers have allowed maps to provide a variety of information and to be done fairly quickly
by cartographers
Cartographers - people who make maps
The Surface of the Earth
Water 71%
Land 29%
Isthmus - a narrow strip of land connecting 2 larger pieces of land (i.e. Panama)
Peninsula - a piece of land that projects out into the water and nearly surrounded by the water
(i.e. Florida)
Land on the earth is created by 2 forces: tectonic forces and gradational process
Tectonic Forces
Plate tectonics - the movement of the earth’s plates
Volcanism - happens on edges of the plates; the magma from the mantle pours onto the earth’s
surface - lava
Folding - plates move toward each other and fold up (i.e. App. Mtns.)
Faulting - plates move apart or slide under one another
Gradational Processes
Weathering - slowly breaks rock down
mechanical - tree roots & frost
chemical - alters the surface of the rocks; oxidation & carbonation
Erosion - the movement of broken down rock particles by wind or water. Glaciers occurred in
North America, Western Europe and Russia thousands of years ago.
Deposition - the final result of erosion. The eroded materials are moved in large quantities by
water, gravity, wind and ocean currents.
Landforms
1. Mountains
2. Hills
3. Plateaus
4. Plains
Mountains and hills are formed by volcanism, folding, and faulting. Mountains are higher in
elevation and more rugged than hills. Hills tend to more populated than mountains. The great
mountain ranges generally occur by plate boundaries.
Plains are low-lying level areas and are sometimes heavily populated. Plateaus are level areas
but have higher elevations than plains.
Elevation is the height of the land above sea level.
Color can be used to show different elevations and the different landforms.
Topographic maps are a better way to show elevation. They use contour lines to connect point of
equal elevations.