Earth Science, 13e

1. Earth Science, 13e Tarbuck & Lutgens

2. Introduction to Earth ScienceEarth Science, 13eChapter 1 Stanley C. Hatfield Southwestern Illinois College

3. Earth Science • Encompasses all sciences that seek to understand • Earth • Earth’s neighbors in space Our Course is Earth and Space Science What is Space Science?

4. Earth Science • Earth Science includes • Geology – literally the “study of Earth” • Oceanography – a study of the ocean • Meteorology – the study of the atmosphere and the processes that produce weather • Astronomy – the study of the universe

5. Space Science • The term space science may mean: a.The study of issues specifically related to space travel and space exploration, including space medicine.[1] b.Science performed in outer space (see space research). c.The study of everything in outer space;[2] this is sometimes called astronomy, but more recently astronomy can also be regarded as a division of broader space science, which has grown to include other related fields.[3]

6. People and the environment • 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

7. 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)

8. Wind EnergyRenewable Energy Resource

9. 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

10. Composite Nightime Image of Earth’s City Lights

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

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

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

14. Scientific inquiry • An idea can become a • 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

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

16. 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

17. 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

18. The Nebular hypothesis

19. 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

20. Earth’s “Spheres” • Hydrosphere • Ocean – the most prominent feature of the hydrosphere • Nearly 71 percent of Earth’s surface • About 97 percent of Earth’s water • Also includes fresh water found in streams, lakes, and glaciers, as well as that found underground

21. Earth’s “Spheres” • Atmosphere • 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

22. 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

23. Earth’s layered structure

24. 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

25. 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)

26. Earth system science • Feedback mechanisms • 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, rock cycle)

27. 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

28. End of Chapter 1