Transcript Earth Science Chap 1.2

Chapter 1
Section 1.1
Earth Science is the name of a
group of sciences that deal with the
Earth and it’s neighbors in space.
 There are four major divisions of Earth
Science.
 1.Geology–the study of Earth (solid earth).
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a. Historical Geology- the study of earth’s
historical development.
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b. Physical Geology -the study of the materials
that make up Earth and the processes that
shape our planet
 2.Oceanography –the study of Earth’s oceans
(composition, movements, processes , life forms and
topography)
 3.Meteorology–the study of Earth’s atmosphere,
climate and weather
 4.Astronomy–the study of the universe beyond Earth.
 Formation of Earth and our solar system
 The Nebular Theory
 A. The nebula was composed mostly of hydrogen and
helium.
 About 5 billion years ago, the nebula began to
contract.
 It assumed a flat, disk shape with the protosun (preSun) at the center
1.The sun began to form in the center of this spinning nebula
 2.Heavier elements were pulled in by the Sun’s gravity,
forming the inner planets.
 3.Outer planets were formed mainly from gases.
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A
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Earth Science Chap 1.2
 Earth’s 4 major spheres
 Atmosphere: all the gases that surround the Earth,
mostly nitrogen 78% and oxygen 21%, includes the
ozone layer
 Biosphere: wherever life is found on Earth, includes
atmosphere, geosphere, and hydrosphere
 Hydrosphere: wherever there is water, like rivers, lakes,
oceans, etc .
 Ocean is the most prominent feature of the
hydrosphere. It is nearly 71% of Earth's surface. It holds
about 97% of Earth's water .
 Also includes fresh water found in streams, lakes, and
glaciers, as well as that found underground.
 Geosphere: includes crust, mantle, and core.
 Crust: least dense, floated to the surface when Earth
was all liquid
 Mantle: solid and more dense than crust
 Outer core: liquid, more dense than mantle and crust
 Inner core: solid because its under high pressure,
most dense part of the geosphere
Plate Tectonics: theory that says
the crust is made up of big pieces
called tectonic plates that move
because of uneven heating in the
mantle
Chap 1.3
 Latitude: the distance north or south of the
equator, measured in degrees. Each degree is 60
minutes, and each minute is 60 seconds.
Latitude ranges from 0o (equator) to 90o (North
or South Pole)
 Longitude: the distance east or west of
the Prime Meridian, measure in degrees.
Longitude ranges from 0o (Prime
Meridian) to 180o (International Date
Line). The Prime Meridian goes through
Greenwich, England.
 Maps: A flat representation of spherical
globe, all maps are a little distorted
because maps are 2 dimensions but
globes are 3 dimensions
 Mercator maps are like a flattened out globes with
sections cut out to keep it accurate
 Topographic maps: show elevation by
using contour lines. If the lines are close
together there’s a steep slope, if the lines
are far apart it’s a flat area
Chap 1.4
 System: A group of interacting parts that all
affect each other and work together, like
hydrosphere, atmosphere, biosphere, and
geosphere all interacting with each other
 Sources of Energy
 Sun—drives external processes such as weather, ocean
circulation and erosional processes
 Earth’s interior—drives internal processes including
volcanoes, earthquakes and mountain building
 Resources: Energy and materials used to support
life, including food, housing, etc
 Nonrenewable: can’t be replaced within a
person’s lifetime (about 70 years), but can
be recycled. Examples include coal, oil,
and minerals
 Renewable: can be replaced within a person’s
lifetime, like animals, plants, solar energy, wind
energy, etc
 Population: The number of organisms of the same
species
 It used to take 1,000s of years to add 1 billion to our
population, now it takes about 15 years
 Why has our population increased so fast?
 Better education, medicine, farming techniques,
sanitation
 World population:
 6.5 billion
 U.S. population:
 A little over 300 million