Chapter 1 Notes
Earth Science – the name for the group of sciences that studies the Earth and its neighbors in space.
4 Branches of Earth Science
1.
Geology – the study of earth. Includes geophysics, geobiology and paleontology.
a. Historical Geology – study of the earth’s geologic history
b. Physical Geology – study of the materials that make up Earth and possible explanations
for the processes that shape our planet.
2. Oceanography – Study of the ocean. Includes movements of seawater, as well as coastal
processes, seafloor topography, and marine life.
3. Meteorology – the study of the atmosphere and the processes that produce weather and
climate.
4. Astronomy – study of the universe.
The Nebular Theory – suggests that the bodies of our solar system evolved from an enormous rotating
cloud called the solar nebula. It was made up of mostly Hydrogen (H) and Helium (He), with a small
percentage of heavier elements. Escaping gases formed the primitive atmosphere.
Layers of the earth
Inner Core – the denser elements, mostly iron and nickel, sunk to the Earth’s center because of gravity
Outer Core – Liquid portion of the core
Mantle – high-density rock
Crust – the thin crust of low-density rock. Includes the lithosphere, continental and oceanic.
Earth’s Major Spheres
1. Atmosphere – thin, life-sustaining, layer of gases that surround the Earth.
2. Hydrosphere – All of the water on Earth.
3. Geosphere – The mostly solid part of the earth below the atmosphere and the oceans. Includes
the core, mantle, and crust.
4. Biosphere – Includes all life on Earth. Plants and animals.
Theory of Plate Tectonics – model to explain how continents move and earthquakes and volcanic
eruptions occur. The Earth’s lithosphere is broken into smaller plates.
Representing the Earth
Latitude – distance North or South of the equator measured in degrees.
Longitude – distance East or West of the prime meridian, measured in degrees.
Map Projections
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Mercator Projection – lines of longitude are parallel making the grid rectangular. Sizes and
distances are distorted, directions are accurate. Used in Navigation.
Robinson Projection – Attempts to minimize overall distortion while showing the entire world at
once. Based on tables of coordinates. Shows most distances, sizes, and shapes accurately.
Most distortions found along the edges.
Conic Projection – Made by wrapping a cone around a globe at a particular line of latitude.
Almost no distortion along the line of latitude along the cone touches, but there is much
distortion in areas away from this line of latitude. Commonly used to make road and weather
maps because of little distortion over smaller areas.
Gnomonic Projection – Made by placing a piece of paper on a globe so that it touches a single
point on the globe’s surface. Various points and lines are then projected onto the paper.
Distances and Directions are distorted, but show greater accuracy the shortest distance
between two points. Used in Navigation. Least distorted at the poles and most distorted at the
equator.
Topographic Maps – Show elevation using contour Lines
a. Contour Lines – line used to connect areas of equal elevation.
b. Contour Interval – tells you the difference in elevation between adjacent contour lines.
c. Hachure lines- Indicate depression
d. Index Contour – Bolded contour lines with numeric elevation
e. Concentric Contour lines – Indicate hill tops
Geologic Maps – Shows the type and age of exposed rocks. (pg 16)
Satellites and Information Technology
Technology allows us to more precisely analyze Earth’s physical properties. The process of computers
gathering data from satellites is called remote sensing. We also use satellites for Global Positioning
Systems(GPS) that allow mobile phones, provide maps to our cars, study and track wildlife, measure
erosion, study earthquakes, as well as plane and ship navigation.
Earth System
Energy Sources
1. Sun – provides energy that drives external processes such as weather.
2. Earth’s Interior Heat – Generated from the decay of radioactive elements. Powers internal
processes that produce volcanoes, earthquakes, and mountains.
People and the Environment
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Our actions produce changes in all of the other parts of the Earth System
Renewable resources can be replenished over relatively short time spans.
Although nonrenewable resources continue to form, the processes that create them are so slow
that it takes millions of years for significant deposits to accumulate.
Human Population is growing exponentially increasing our demands on the earth’s resources.
Significant threats to the environment include air pollution, acid rain, ozone depletion, and
global climate change.
Scientific Theory vs. Law
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A theory is a well-established, highly reliable explanation of natural phenomena. A scientific
theory unifies a broad range of observations and hypotheses and enables scientists to make
accurate predictions about new situations.
Laws differ from theories. Scientific Laws are concise, specific statements that summarizes a
pattern found in nature.