Chapter 2 Lecture

McKnight's
Physical Geography
11e
Lectures

Chapter 1
Introduction to Earth

Andrew Mercer
Mississippi State University
© 2014 Pearson Education, Inc.

© 2014 Pearson Education, Inc.

Learning Goals of This Chapter
• Distinguish the key concerns for geographers who study the world.
• Analyze how geographers use science to explain and understand the natural environment.
• Identify the four environmental “spheres” of Earth.
• Illustrate how the concept of Earth systems helps us to understand the interrelationships of the four environmental “spheres” of Earth.
• Describe Earth’s relationships within the solar system. • Compare the size of Earth with the size of its surface features.
© 2014 Pearson Education, Inc.

Learning Goals of This Chapter
• Determine the latitude of a location on Earth.
• Determine the longitude of a location on Earth.
• Locate a place given the latitude and longitude coordinates. • Explain how latitude and longitude together identify a location on Earth.
• Summarize the factors that cause the annual change of seasons.
• Describe the changes in the patterns of sunlight around Earth during the year.
• Explain how time zones were established.
© 2014 Pearson Education, Inc.

Learning Goals of This Chapter
• Describe how time zones are used to establish actual times around the world.
• Discuss the relationship between time zones and the international dateline.

© 2014 Pearson Education, Inc.

Introduction to Earth
• Geography and Science
• Environmental Spheres and Earth
Systems
• Earth and the Solar System
• The Geographic Grid – Latitude and
Longitude
• Earth–Sun Relations and the Seasons
• Telling Time

© 2014 Pearson Education, Inc.

Geography and Science
• Definition
• Sciences that branch from geography
• Physical versus cultural • Summary of global environmental change
• Globalization – definition and its role in geography © 2014 Pearson Education, Inc.

Geography and Science
• The scientific method
– Observe phenomena
– Formulate a hypothesis
– Design an experiment to test the hypothesis
– Predict the outcome of the experiment
– Conduct the experiment
– Draw conclusions

• Scientific “proof”
• Establishment of scientific theory
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Geography and Science
• Measurement systems
– Need measurement systems to quantify scientific processes
– SI versus English units
– Conversions

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Geography and Science
• Unit conversions m  mi  1 hr  1.6 km  1000 m 


 31.1
70   s  hr  3600 s  1 mi  1 km 

© 2014 Pearson Education, Inc.

The Environmental Spheres
• Four primary spheres
1.
2.
3.
4.

Lithosphere – “stone”
Atmosphere – “air”
Hydrosphere – “water”
Biosphere – “life”

1

2

4

3

Interactions between the spheres

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The Environmental Spheres
• Earth systems
– Closed systems – those contained from outside influence – Open systems – energy and matter free to be exchanged across systems
– Equilibrium – systems are in balance (input = output) – Interconnected systems – change in one system affects another (example of a glacier)
– Feedback loops, positive versus negative

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Earth and the Solar System
• Origins – the big bang
• Formation of the solar system – Formed 4.5 to 5 billion years ago from a nebula
– Eight planets revolve around the Sun in elliptical orbits
– Four terrestrial planets
– Four gas giants
– Earth is the third planet
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Earth and the Solar System
• The solar system

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Earth and the Solar System
• Earth’s physical characteristics – Maximum relief
– See figure

– Imperfect sphere
– Equatorial diameter ~
12,756 km
– Polar diameter ~
12,714 km

– Circumference of
40,000 km
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The Geographic Grid – Latitude and Longitude

• Location on Earth
– Need an accurate location on Earth to describe geographic features – Use Earth’s rotation axis to