Earth sciences

(science and technology) The science that deals with the earth or any part thereof; includes the disciplines of geology, geography, oceanography, and meteorology, among others.

Sciences that involve attempts to understand the nature, origin, evolution, and behavior of the Earth or of its parts and to comprehend its place in the universe, especially in the solar system. Understanding has advanced primarily through improved appreciation of the complex, usually cyclical interactions that take place among distinct parts of the Earth such as the lithosphere, atmosphere, hydrosphere, and biosphere. Geophysics is the study of the physics of the Earth, emphasizing its physical structure and dynamics. Geochemistry is the study of the chemistry of the Earth, dealing with its composition and chemical change. Geology is the study of the solid Earth and of the processes that have formed and modified it throughout its 4.5-billion-year history. See also Geochemistry; Geodesy; Geology; Geophysics; Solar system.

Many branches of geology are considered separate sciences. Mineralogy is the study of the composition, structure, and properties of minerals. Petrology involves understanding how rocks originate and evolve, as well as rock description and classification. Specialties related to petrology include sedimentology and volcanology. Stratigraphy is the study of the origin, age, and development of layered, generally sedimentary rocks. Paleontology is the study of ancient (fossil) life. Historical geology is the study of the evolution of the Earth and its life. Geomorphology is the study of landscapes and their evolution. Seismology is the study of earthquakes and their effects. Structural geology is the study of deformed rocks. Engineering geology relates to the support of human constructions by underlying rock. See also Engineering geology; Geology; Geomorphology; Hydrology; Mineralogy; Paleontology; Petrography; Petrology; Seismology; Stratigraphy; Structural geology; Volcanology.

Oceanography is the study of the oceans; limnology, the study of lakes; hydrology, the study of underground and surface water; and glaciology, the study of glaciers, ice caps, and ice sheets. These disciplines address the study of water in and on the Earth. The gaseous outer parts of the planet are the province of the atmospheric sciences, including meteorology, which is concerned with the weather and weather forecasting; climatology, which deals with longer-term and regional variations; and aeronomy which, because it deals with the outermost ionized region of the atmosphere, is much concerned with solar terrestrial interactions, including the aurora borealis and aurora australis. The biosphere embodies all life on Earth, and its study includes molecular biology, zoology, botany, and ecology. Geography, the study of all that happens at the Earth's surface, has been distinct insofar as it has encompassed not only physical and biological sciences but also the social sciences, including aspects of political science and economics. This distinction is fading rapidly as other earth sciences become more involved with social considerations.