Overview of Earth Science Earth science is the name for the group of sciences that deals with Earth and its neighbors in space. Earth science includes many subdivisions of geology such as geochemistry, geophysics, geobiology and paleontology, as well as oceanography, meteorology, and astronomy.
Units 1 through 4 focus on the science of geology, a word that means “study of Earth.” Geology is divided into two broad areas—physical geology and historical geology. Physical geology includes the examination of the materials that make up Earth and the possible explanations for the many processes that shape our planet. Processes below the surface create earthquakes, build mountains, and produce volcanoes. Processes at the surface break rock apart and create different landforms. Erosion by water, wind, and ice results in different landscapes. You will learn that rocks and minerals form in response to Earth’s internal and external processes.
Understanding the origin of rocks and minerals is an important part of understanding Earth. In contrast to physical geology, the aim of historical geology is to understand Earth’s long history. Historical geology tries to establish a timeline of the vast number of physical and biological changes that have occurred in the past. See Figure 1. We study physical geology before historical geology because we must first understand how Earth works before we try to unravel its past.
Scientists called paleontologists study fossils, which are signs of life in the distant past, to find out how life-forms have changed through time. Posing Questions What questions do you have about this fossil?
What are the two main areas of geology?
Unit 5 is devoted to oceanography. Oceanography integrates the sciences of chemistry, physics, geology, and biology. Oceanographers study the composition and movements of seawater, as well as coastal processes, seafloor topography, and marine life. See Figure 2. Unit 6 examines the composition of Earth’s atmosphere.
The combined effects of Earth’s motions and energy from the sun cause the atmosphere to produce different weather conditions. This, in turn, creates the basic pattern of global climates. Meteorology is the study of the atmosphere and the processes that produce weather and climate. Like oceanography, meteorology also involves other branches of science. Unit 7 demonstrates that understanding Earth requires an understanding of Earth’s position in the universe. The science of astronomy, the study of the universe, is useful in probing the origins of our own environment.
All objects in space, including Earth, are subject to the same physical laws. Learning about the other members of our solar system and the universe beyond helps us to understand Earth. Throughout its long existence, Earth has been changing. In fact, it is changing as you read this page and will continue to do so. Sometimes the changes are rapid and violent, such as when tornados, landslides, or volcanic eruptions occur. Many changes, however, take place so gradually that they go unnoticed during a lifetime.