Earth science is the study of the physical components of Earth—its water, land, and air—and the processes that influence them. Earth science can be thought of as the study of the five physical spheres of Earth: atmosphere (gases), lithosphere (rock), pedosphere (soil and sediment), hydrosphere (liquid water), and cryosphere (ice).
Earth scientists, then, must consider interactions between all three states of matter—solid, liquid, and gas—when performing investigations. The subdisciplines of Earth science are many, and include the geosciences, oceanography, and the atmospheric sciences.
The geosciences involve studies of the solid part of Earth and include geology, geochemistry, and geophysics. Geology is the study of Earth materials and processes. Geochemistry examines the composition and interaction of Earth's chemical components. Geophysicists study the dynamics of Earth and the nature of interactions between its physical components.
Oceanography is the study of all aspects of the oceans: chemistry, water movements, depth, topography, etc.
The atmospheric sciences, meteorology and climatology, involve the study of Earth's weather. Meteorology is the study of the physics and chemistry of the atmosphere. One of the primary goals of meteorology is the analysis and prediction of short-term weather patterns. Climatology is the study of long-term weather patterns, including their causes and variations.
To better understand the highly involved and interrelated systems of Earth, scientists from these different subdisciplines often must work together. Today, Earth science research focuses on solving the many problems posed by increasing human populations, decreasing natural resources, and inevitable natural hazards. Computer and satellite technologies are increasingly used in this research.
[ See also Earth ; Geology ; Oceanography ; Weather ]