Transcript Chapter 2

Chapter 2
A Living Planet
Section 1
The Earth Inside and Out
Solar System
 Continents- Land masses above water on
earth. They fit together like a jigsaw puzzle.
(Example: South America-Africa.
 Solar System- Consist of the Sun and nine
know planets. The earth is the 3rd planet from
the sun.
The Structure of Earth:
Inside the Earth
 Core-is the solid metallic center of the earth
and is made up of iron and nickel under
tremendous pressure.
 Mantle-a soft layer of molten rock about
1,800 miles thick.
 Magma-molten rock created when the mantle
melts the under side of the crust.
 Crust-the then layer of rock on the earths
surface.
The Structure of The Earth:
On and Above the Earth
 Atmosphere-a layer of gases surrounding the earth.
Contains oxygen we breath and protects the earth
from space debris. Helps control the climate.
 Lithosphere-The solid rock portion of the earths
surface. Some of the lithosphere is below water and
forms the ocean floor.
 Hydrosphere-Water elements on the earth. (lakes,
oceans, rivers, and seas).
 Biosphere-all three spheres combined to form the
place where plants and animals live.
Continental Drift
 Continental Drift- A theory that states all of
the continents used to be connected and
were a super continent called Pangaea.
Section 2
Bodies of Water and Landforms
Bodies of Water
 Oceans and Seas- The ocean is an
interconnected body of salt water that
covers 71% of the earth. Geographers
divide the ocean into 4 parts; Atlantic,
Pacific, Indian, and Artic Ocean.
 Ocean Motion-Ocean water circulates
through TIDES, WAVES, and CURRENTS.
 The circulation of the ocean helps distribute
heat on the planet. Winds blow over the
ocean and are either heated or cooled.
Bodies of Water
 Hydrologic Cycle -Continuous circulation of
water between atmosphere, oceans, and the
earth.
 Lakes, Rivers, and Streams- Lakes hold more
that 95% of the earths fresh water supply. A
drainage basin is an area drained by a river
and its tributaries. Salt water lakes are
formed when rivers deposit salt and there is
not out flow of water.
Bodies of Water
 Ground Water- Water held in pores of rock.
The level at which the water is saturated
marks the rim of the Water Table.
Landforms
 Oceanic Landforms- The earth’s surface from
the edge of a continent to the deepest part of
the ocean floor is known as the Continental
Shelf. Many features found on the earth’s
surface are also found on the ocean floor.
 Continental Landforms- Relief is the
difference in elevation between the highest
point and lowest point of a land form. There
are four categories of relief; mountains, hills,
plains, and plateaus.
Landforms
 Topography-is the combination of the surface
shape composition of the landforms and their
distribution in a region. Topographic map
shows landforms with their vertical
dimensions and their relationship to other
landforms.
Section 3
Internal Forces Shaping The Earth
Plate Tectonics
 Internal forces that shape the earth begin
immediately under the earths crust. Magma
beneath the earth circulates constantly.
Tectonic plates ride above the circulation of
magma.
 Tectonic Plates-Enormous moving pieces of
land that form the earth’s crust
Tectonic Plates Cont.
 Tectonic Plates move in four ways.
1. Spreading-moving apart
2. Subduction-diving under another plate
3. Collision-crashing into another plate
4. Sliding-shear one another as they pass
Tectonic Plates Cont.
 Divergent boundaries-Plates move apart or
spread.
 Convergent boundaries-Plates collide
 Transform boundaries-Plates slide past one
another.
Tectonic Plates Cont.
 Folds- some rock becomes more flexible
under pressure and as the plates move. This
creates slow changes in the earths crust.
 Faults-Some rocks are so hard that they can
not become flexible so they fracture under
pressure this is called a fault. A fault line is
the place where the plates move against one
another.
Earthquakes
 Earthquakes- are violent movements that
occur when plates grind against each other at
a fault.
 Seismograph-is a special devise that helps
scientist detect earth quakes.
 Focus-Is the location on earth where an
earthquake begins.
 Epicenter-Is the location directly above the
focus.
Earthquake Damage
 Earthquakes can cause severe damage.
Including landslides, fires (ruptured gas
lines), and collapsed buildings.
 Richter Scale-Uses information from
seismographs to determine the intensity of an
earthquake.
 Tsunami-Is a large wave generated by an
earthquake that spreads out from the
epicenter. Waves can travel 450 MPH.
Generally waves reach 50-100 feet. The
record wave is 238 ft.(20 stories) in Japan.
Volcanoes
 Magma, gases, and water from the lower
crust or parts of the mantle collect in
chambers. Eventually enough pressure
builds and the lava, gas, and water explode
from the earths crust. A volcano is a crack in
the earths surface where the materials pour
out.
 Lava-is magma that reaches the earth’s
surface.
Volcanoes Cont.
 Volcano eruptions are very unpredictable. A
volcano can remain inactive for hundreds of
years before becoming active again.
 Ring of Fire-A zone around the rim of the
Pacific Ocean where most of the worlds
active volcanoes exist.
Sect. 4 External Forces
Shaping the Earth
 Weathering-refers to the physical and
chemical processes that change the
characteristics of rock on or near the earths
surface.
 Sediment-is smaller and smaller pieces of
rock created by weathering. Usually sand,
mud, or silt.
Weathering
 Mechanical Weathering-A process that
breaks rock into smaller pieces. Examples
Ice crystals and plant roots can form in the
cracks of rocks and eventually break them
apart.
 Chemical Weathering - occurs when rock is
changed into a new substance as the result
of interaction between elements in water, air,
and the rocks. Examples: Cave formations,
Iron rusting, and Acid Rain.
Erosion
 Erosion-occurs when weathered material is
moved by water, wind, ice, or gravity.
 Water erosion- occurs as water carries
particles down stream. Abrasion from the
particles eat away the rock forming the river
bed.
 Deltas-a fan shaped landform resulting from
the deposit of silt at the mouth of rivers.
Erosion
 Wind Erosion-When wind speeds reach 11
miles per hour, the wind carries sediments
and deposits them in different locations.
 Loess-are deposits of wind blown sediment
that produce very fertile soils.
Glacier Erosion
 Glacier- is a large, long lasting mass of ice
that moves due to gravity.
 Glaciation-is the changing of landforms due
to the movement of glaciers.
 Moraine-ridges and hills left behind from
moving glaciers.
U shaped
V shaped
Building Soil
 Humus-organic material is soil.
 Soil factors
 Parent Material-Chemical composition of the
parent rock.
 Relief-Steeper slopes are eroded quickly and
do not produce soil quickly.
 Organisms-small animals, plants, and
bacteria that help loosen the soil and provide
nutrients.
Soil Factors Cont.
 Climate-Climate plays a huge factor in soil
production.
 Time-the amount of time it takes to make soil
varies.