A combination of all living things on Earth—plants, animals, birds, marine life, insects, viruses, single-cell organisms, and so on—as well as all formerly living things that have not yet decomposed.
A tectonic process whereby plates move toward each other. Usually associated with subduction, convergence typically occurs in the ocean, creating an oceanic trench. It is one of the three ways, along with divergence and transform motion, in which plates interact.
The uppermost division of the solid earth, representing less than 1% of its volume and varying in depth from 3 to 37 mi. (5 to 60 km). Below the crust is the mantle.
The movement of soil and rock due to forces produced by water, wind, glaciers, gravity, and other influences.
The study of the solid earth, in particular its rocks, minerals, fossils, and land formations.
An area of geology concerned with the study of land-forms, with the forces and processes that have shaped them, and with the description and classification of various physical features on Earth.
A branch of the earth sciences that combines aspects of geology and physics. Geophysics addresses the planet's physical processes as well as its gravitational, magnetic, and electric properties and the means by which energy is transmitted through its interior.
The upper part of Earth's continental crust, or that portion of the solid earth on which human beings live and which provides them with most of their food and natural resources.
The study of Earth's physical history. Historical geology is one of two principal branches of geology, the other being physical geology.
A notable topographical feature, such as a mountain, plateau, or valley.
The upper layer of Earth's interior, including the crust and the brittle portion at the top of the mantle.
The transfer of earth material, by processes that include flow, slide, fall, and creep, down slopes. Also known as mass movement.
The study of the material components of Earth and of the forces that have shaped the planet. Physical geology is one of two principal branches of geology, the other being historical geology.
The name both of a theory and of a specialization of tectonics. As an area of study, plate tectonics deals with the large features of the lithosphere and the forces that shape them. As atheory, it explains the processes that have shaped Earth in terms of plates and their movement.
Large, movable segments of the lithosphere.
Involving a comparison between qualities that are not defined precisely, such as "fast" and "slow" or "warm" and "cold."
Involving a comparison between precise quantities—for instance, 10 lb. versus 100 lb. or 50 mi. per hour versus 120 mi. per hour.
Elevation and other in equalities on a land surface.
Material deposited at or near Earth's surface from a number of sources, most notably preexisting rock.
The study and interpretation of sediments, including sedimentary processes and formations.
A term that refers either to the process of subsiding (settling or descending), on the part of either air or solid earth or, in the case of solid earth, to the resulting formation. Subsidence thus is defined variously as the downward movement of air, the sinking of ground, or a depression in Earth's crust.
Any set of interactions that can be set apart mentally from the rest of the universe for the purposes of study, observation, and measurement.
The study of tectonism, including its causes and effects, most notably mountain building.
The deformation of the lithosphere.
The configuration of Earth's surface, including its relief, as well as the position of physical features.
A process whereby the surface of Earth rises, due to either a decrease in downward force or an increase in upward force.
The breakdown of rocks and minerals at or near the surface of Earth due to physical or chemical processes.
Comment about this article, ask questions, or add new information about this topic: