1. Edward J. Tarbuck & Frederick K. Lutgens
Earth Science, 6e
Edward J. Tarbuck & Frederick K. Lutgens

2. Earth's “Spheres"

3. Earth Science Encompasses all sciences that seek to understand
Earth's neighbors in space
Earth Science includes
Geology - literally the “study of Earth”
Oceanography – a study of the ocean

4. Earth Science Earth Science includes
Meteorology - the study of the atmosphere and the processes that produce weather
Astronomy - the study of the universe

5. Earth's “Spheres" Hydrosphere
Ocean – the most prominent feature of the hydrosphere
Nearly 71% of Earth's surface
About 97% of Earth's water
Also includes fresh water found in streams, lakes, and glaciers, as well as that found underground

6. Earth's “Spheres" Atmosphere Biosphere Thin, tenuous blanket of air
One half lies below 5.6 kilometers (3.5 miles)
Biosphere
Includes all life
Concentrated near the surface in a zone that extends from the ocean floor upward for several kilometers into the atmosphere

7. Earth's “Spheres" Solid Earth
Based on compositional differences, it consists of the crust, mantle, and core
Divisions of the outer portion are based on how materials behave
Lithosphere - rigid outer layer
Divisions of Earth’s surface - continents and ocean basins

8. Earth’s layered structure

9. Earth system science
Earth is a dynamic body with many separate but highly interacting parts or spheres
Earth system science studies Earth as a system composed of numerous parts, or subsystems
System - any size group of interacting parts that form a complex whole

10. Earth system science System
Closed systems are self-contained (e.g. an automobile cooling system)
Open systems - both energy and matter flow into and out of the system (e.g. a river system)

11. Earth system science Feedback mechanisms Earth as a system
Negative feedback mechanisms resist change and stabilize the system
Positive feedback mechanisms enhance the system
Earth as a system
Consists of a nearly endless array of subsystems (e.g. hydrologic cycle)

12. The hydrologic cycle

13. Earth system science Earth as a system 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
Humans are part of the Earth system

14. People and the environment
Surrounds and influences organisms
Physical environment encompasses water, air, soil, and rock
Term “environmental” is usually reserved for those aspects that focus on the relationships between people and the natural environment

15. People and the environment
Resources
An important focus of the Earth sciences
Includes water, soil, minerals, and energy
Two broad categories
Renewable – can be replenished (examples include plants and energy from water and wind)
Nonrenewable – metals (examples include metals and fuels

16. People and the environment
Population
Population of the planet is growing rapidly
Rate of mineral and energy usage has climbed more rapidly than the overall growth of population
Environmental problems
Local, regional, and global

17. Growth of world population

18. People and the environment
Environmental problems
Human-induced and accentuated
Urban air pollution
Acid rain
Ozone depletion
Global warming
Natural hazards
Earthquakes
Landslides

19. People and the environment
Environmental problems
Natural hazards continued
Floods
Hurricanes
World population pressures

20. Early evolution of Earth
Origin of Earth
Most researchers believe that Earth and the other planets formed at essentially the same time
Nebular hypothesis
Solar system evolved from an enormous rotating cloud called the solar nebula
Nebula was composed mostly of hydrogen and helium

21. Early evolution of Earth
Origin of Earth
Nebular hypothesis continued
About 5 billion years ago the nebula began to contract
Assumes a flat, disk shape with the protosun (pre-Sun) at the center
Inner planets begin to form from metallic and rocky clumps
Larger outer planets began forming from fragments with a high percentage of ices

22. The Nebular hypothesis

23. Early evolution of Earth
Formation of Earth’s layered structure
As Earth formed, the decay of radioactive elements and heat from high-velocity impacts caused the temperature to increase
Iron and nickel began to melt and sink toward the center
Lighter rocky components floated outward, toward the surface
Gaseous material escaped from Earth’s interior to produce the primitive atmosphere

24. Scientific inquiry Science assumes the natural world is
Consistent
Predictable
Goal of science
To discover patterns in nature
To use the knowledge to predict

25. Scientific inquiry An idea can become a Scientific method
Hypothesis (tentative or untested explanation)
Theory (tested and confirmed hypothesis)
Paradigm (a theory that explains a large number of interrelated aspects of the natural world)
Scientific method
Gather facts through observation
Formulate hypotheses and theories

26. Scientific inquiry Scientific knowledge is gained through
Following systematic steps
Collecting facts
Developing a hypothesis
Conduct experiments
Reexamine the hypothesis and accept, modify, or reject
Theories that withstand examination
Totally unexpected occurrences

27. End of Introduction