The Introduction opens with a brief discussion of Earths four “spheres.” A definition of Earth science is followed by a discussion of the four areas that are traditionally included—geology, oceanography, meteorology, and astronomy. The importance of understanding basic Earth science principles when examining resources and environmental issues is also presented. The Introduction closes with a discussion of the nature of scientific inquiry.
Learning Objectives
After reading, studying, and discussing the Introduction, you should be able to:
•Describe Earth’s four “spheres.”
•List the sciences traditionally included in Earth science.
•Discuss some resource and environmental issues.
•Describe the nature of scientific inquiry.
Chapter Summary
•The four “spheres” of Earth are 1) the hydrosphere, the dynamic mass of water that is continually on the move; 2) the atmosphere, the gaseous envelope surrounding Earth; 3) the biosphere, which includes all life; and 4) the lithosphere, which refers to the rigid outer layer of Earth. The solid Earth is divided into the core, mantle, and crust. The lithosphere includes the crust and part of the upper mantle.
•Earth science is the name for all the sciences that collectively seek to understand Earth and its neighbors in space. It includes geology, oceanography, meteorology, and astronomy.
•Environment refers to everything that surrounds and influences an organism. These influences can be biological, social, or physical. Resources are an important environmental concern. The two broad categories of resources are 1) renewable, which means that they can be replenished over relatively short time spans, and 2) nonrenewable.
•Environmental problems can be local, regional, or global. Human-induced problems include urban air pollution, acid rain, ozone depletion, and global warming. Natural hazards imposed by the physical environment include earthquakes, landslides, floods, and hurricanes. As world population continues to grow, pressures on the environment increase as well.
•All science is based on the assumption that the natural world behaves in a consistent and predictable manner. The process through which scientists gather facts through observations and formulate scientific hypotheses, theories, and laws, is called the scientific method. To help determine what is occurring in the natural world, scientists often 1) collect facts, 2) develop a scientific hypothesis, 3) construct experiments to validate the hypothesis, and 4) accept, modify, or reject the hypothesis on the basis of extensive testing. Other discoveries represent purely theoretical ideas which have stood up to extensive examination. Still other scientific advancements have been made when a totally unexpected happening occurred during an experiment.