Key Earth Science Terms: Definitions and Concepts

Posted on Dec 14, 2024 in Geology

Badlands: An area with an abundance of soft sediments heavily eroded by wind and water.
Barranco: A landform characteristic of the Canary Islands; a narrow, steep, short valley created by the flow of streams in volcanic ash.
Bay: An inlet of the sea into the coast, of considerable size and generally smaller than a gulf.

Calderas: Cavities in the crater of a volcano caused by explosion or collapse.
Canyon: A river valley with steep walls, usually occurring in hard rock, and more typical of limestone.
Cartography: The science and art of mapmaking.
Cerros Witness: Isolated elevations consisting of soft layers and a top layer of limestone, originating from a moor.
Changing Latitude: A geographic space that is in a different latitude and placed in the appropriate space.
Charnela: The point where the sides of a fold bend, changing the dip.
Circus: A semicircular depression carved by a glacier where snow accumulates.
Clays: Soft, waterproof rock of different colors according to their origin and composition.
Combe: Deep and wide valleys typical of an Appalachian relief (hard materials) formed by erosion.
Contour: A line joining points at the same elevation, typically plotted at 10-meter or 20-meter intervals.
Countryside: A sedimentary depressed area where the material has been eroded, resulting in a gently undulating plain (hills, basins, etc.); often associated with agricultural activity.
Craters: The top of a volcano, shaped like a funnel or pit.

Deforestation: The process, usually caused by human activity, of destroying forest areas.
Delta: A coastal landform created when a river deposits more sediment than the sea can redistribute.
Depression: An area of land that is lower than the surrounding land.
Desertification: The loss of topsoil.
Detachment: The falling of rock fragments.
Destruction of the Environment: The complete disappearance of environmental elements.
Diaclase: A fissure or fracture in rocks where no movement has occurred.
Dolina: A cavity typical of karst limestone landscapes in Spain.
Dome: A boss or rounded protuberance; in Spain, a typical feature of siliceous landscapes.
Dunes: Sand mounds characteristic of sandy coasts, formed by the accumulation of wind-transported sand, often stabilized by vegetation.

Ecuador: The imaginary line that divides the Earth into two roughly equal hemispheres (Northern and Southern); its circumference is just over 40,000 km, corresponding to the 0° parallel.
Endogenous: Phenomena produced inside the Earth.
Epirogenesis: Vertical tectonic uplifting or subsidence of the land.
Equinox: The time of year when the line separating the illuminated and dark areas of the Earth passes through both poles simultaneously (September 23 – Autumnal Equinox, March 21 – Vernal Equinox).
Erosion: The process by which natural forces wear away and transport rock and soil.
Escarpment: An abrupt upper structure.
Estany: A glacial lake in Catalonia.
Stalactite: An elongated limestone formation hanging from the roof of a cave.
Stalagmite: An elongated limestone formation rising from the floor of a cave.
Strait: A narrow passage of water connecting two seas or two large bodies of water; also called a channel.

Fault: A fracture in the Earth’s crust along which rocks have moved.
Flanks: The sides of a fold.
Fracture: A rupture in the Earth’s crust without separation of the fractured blocks.
Fractured Structures: Relief consisting of hard materials that are fractured and may rise or sink, but never fold.

Geography: The science that studies, analyzes, and describes the Earth.
Geomorphology: The science that studies landforms.
Geosyncline: A”sunken lan” where sedimentary material accumulates, later forming mountains.
Gneiss: A crystalline rock, generally coarse-grained and with a layered texture.
Graben: A downthrown block that moves along normal faults in a staggered manner.
Greenhouse Effect: The increase in Earth’s temperature due to the emission of large amounts of methane and CO2, which allow sunlight to enter but prevent heat from escaping.
Gullied: A phenomenon occurring on rocks due to erosion (water, ice, etc.), causing pitting.
Gullies: Landforms produced by heavy rains on slopes.

Internal Forces: Forces from within the Earth that can cause orogeny or epirogenesis.

Mapping: The set of scientific and technical studies devoted to the preparation of maps.

External Forces: Forces that drive the cycles of erosion, transport, and sedimentation.

Polar Circle: An imaginary line demarcating areas of the Earth where the length of day and night exceeds 24 hours at least once a year; there are two: the Arctic Circle in the north and the Antarctic Circle in the south.

Scale: The relationship between the size of a representation and the actual size of what it represents; expressed numerically or linearly.
Sedimentary Basin: An area where sedimentation processes occur, depositing various materials depending on the location (deep water, inland seas, continental shelf).
Shield: An old continental-scale, rigid, compact mass that has remained stable, although it may have bulged or fractured.
Structure: The arrangement of rocks.
Horizontal or Aclinal Structure: Relief formed by horizontal strata of soft materials (wilderness, countryside, hills).
Monoclinal or Sloping Structure: Relief formed by soft materials with a dip (inclination of the layer) less than 15°.
Folded Structure: Elevations due to anticlines (convex folds) and synclines (concave folds).

Volcanic Cone: An elevation with an open cone at the top, caused by the accumulation of volcanic material around the emission vent during an explosive activity phase.