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
© 2014 Pearson Education, Inc.
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
© 2014 Pearson Education, Inc.
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
© 2014 Pearson Education, Inc.
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
© 2014 Pearson Education, Inc.
Earth and the Solar System
• The solar system
© 2014 Pearson Education, Inc.
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
© 2014 Pearson Education, Inc.
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