Glossary of Geographical Terms

Glossary of Geographical Terms

Ablation: Loss of ice in the body of a glacier through melting etc.

Abrasion: Erosion of rocks by water, wind or ice (glacier).

Alluvium: The fine debris transported and deposited by a river. Landforms formed by deposition of such material are called alluvial landforms, for example, alluvial plains. Soils formed through river deposition are called alluvial soils.

Altimeter: A type of aneroid barometer for measuring height, used mainly in aeroplanes.

Anemometer: An instrument used for measuring wind velocity.

Anticline: The arch or crest of a fold in the rocks. Its opposite is a syncline, the bottom of a fold.

Antipodes: Two points diametrically opposite on the surface of earth.

Apogee: The position of the moon or any other heavenly body, when it is at its greatest distance from the earth. At s shortest distance from the earth the moon is said to be xi perigee.

Atoll: A ring or horseshoe-shaped coral reef.

Attrition: Mutual wearing down of rock particles during transportation by wind, water or ice.

Aurora Australis and Aurora Borealies: The light phenomena seen in the sky at night in the higher latitudes of the southern and northern hemisphere respectively. Aurora comprises an electrical discharge and is usually accompanied by a magnetic storm.

Avalanche: Alarge mass of snow and ice at high altitude, sliding downslope on a mountain. Usually a large amount of rock material is also involved in an avalanche.

Azonalsoil: Soil which hasnotbeensubjected sufficiently to soil forming processes and thus has changed little from the parent material. Such soils do not have a mature profile.

Barometer: Instrument used for measuring pressure. A self-recording barometer giving a continuous record of pressure conditions in the form of a line graph is called a rarograph and the graph thus provided is called a barogram.

Barysphere, Bathysphere or Centrosphere: Inner portion of the earth below the lithosphere or outer crust.

Base level: The lowest level to which a river can deepen its valley. It is the level of the surface of the water body, a lake or sea, in which the stream finally falls.

Beach: A gently sloping strip of land along the coast. This lies between the high and low tide levels and is formed by depositional action of waves.

Bearing: The horizontal angle between the direction of an object and the meridian through the observer, measured in degrees (zero to 360) clockwise from the north.

Beufort scale: A scale identifying wind strength. The lowest point on the scale is zero which refers to calm conditions and the highest is 12 referring to a hurricane.

Biogeography: Study of geographical distribution of plants and animals.

Blizzard: A storm of powdery snow in the Polar Regions.

Bog: An area of soft, wet, spongy ground consisting mainly of decayed or decaying moss and other vegetable matter.

Bora: A cold and often dry wind experienced along the eastern coast of the Adriatic Sea.

Bora: A high tidal wave causing backflow of water in river.

Caatinga: Thom-forest of Brazil.

Canyon: A narrow, deep, steep-sided river valley cut in the soft rocks.

Cape: A headland, a more or less pointed piece of land jutting out into the sea.

Cardinal points: The four main directions of the compass.

Cartography: The art of drawing maps and charts.

Chaparral: The low, dense scrub, characteristic of Mediterranean type of climatic regions.

Chronometer: An accurate time-keeping instrument.

Climatology: The science studying climates and their influence on other components of the environment.

Clinometer: An instrument used for determining the difference in elevation between two points.

Cloud: A mass of tiny water droplets or ice crystals formed by condensation of water vapour in the atmosphere.

Condensation: The process by which a substance changes from vapour to liquid.

Coniferous: Cone-bearing plants with needle-shaped leaves.

Connate water: Water entrapped in the interstices of rocks during their formation; also called fossil water.

Convection: The uplift of air as a result of surface heating or instability due to other reasons. Generally this term refers to vertical movement of gases in contrast to advection.

Coral: A kind of rock formed of polyps forming reefs in the oceans.

Colour of the sky: Seems blue because of the selective scattering of light in the atmosphere by gases and dust particles.

Cryophyte: Any plant, mosses, fungi or bacteria that grows on ice or snow fin tundra region also.

Deciduous forest: Consists of trees that shed their leaves in the dry season.

Downs: Grasslands of Australia.

Ecology: Studies of organisms in relation to their environment.

Epicentre: Point on the surface of the earth vertically above the seismic focus or deep focus, that is, the point where an earthquake originates.

Estuary: Mouth of a river where tidal effects are evident and where fresh water and sea water mix. The term also refers to river valleys which have been flooded by sea due to coastal subsidence.

Fathometer: Instrument used for measuring the depth of the ocean.

Fauna: The animal life of a region or a geological period.

Fiord: A glacial valley or part there of now under the sea.

Flood-Plain: A plain bordering a river and formed by river deposition.

Flora: The plant life of a region or geological period.

Fluvial: Belonging or relating to a river.

Pog: A dense mass or small water drops or smoke or dust particles in the lower layers of the atmosphere.

Geosyndine: Alarge depression or trough in the earth's crust, that is a syncline on a large scale.

Geyser: A thermal spring which throws up a jet of hot water and steam intermittently.

Glacier: A moving mass of ice.

Gorge: A narrow and deep valley of a river.

Great circle: A circle on the earth's surface whose plane passes through its centre and thus bisects it into two hemispheres.

Great circle route: A route between any two points on the earth's surface which follows the great circle between them.

Gulf: A large, deep bay.

Habitat: Natural environment of a plant or animal.

Halophyte: A plant which grows naturally in saline environment.

Hemisphere: One half of the earth's surface, formed when a plane passing through its centre bisects it.

Hinterland: Area from which a port gets most of its exports.

Horse latitudes: Subtropical belt of high pressure over the oceans.

Humus: Decomposed and partly decomposed organic matter in the soil.

Hydrology: The study of the water content on the earth.

Hyetograph: A moisture-laden winds.

Hygrometer: Instrument used for measuring humidity in the atmosphere.

Hygrophyte: Plant growing in wetlands.

Iceberg: A mass of land ice which has been broken off or carved from the end of a glacier and is afloat in the sea.

Illuviation: Deposition, in the lower soil horizon, of material removed by eluviation from the upper horizons of the soil.

Insolation: Energy radiated from the sun received by the earth.

Karst region or Karstland: Limestone region in which most of the drainage is underground, the surface being dry and barren.

Katabatic wind: Local wind caused by the flow of air down mountain slopes and valleys.

Lagoon: Part of sea partially cut off from it by deposits of sand or coral reefs, viz. Chilika Lake in Odisha.

Latitude: The angular distance of a point on the earth's surface north or south of the equator, as measured from the centre of the earth. Latitudinal lines are also called parallels of latitude.

Leaching: The process by which soluble substances are washed out of the upper layers of the soils into lower layers by percolating rainwater.

Leeward: The side or direction sheltered from the wind.

Lithophyte: A plant that grows on bare rock or stone.

Loess: A deposit of fine silt or dust generally held to have been transported to its present situation by wind.

Magnetic storms: Large, irregular variations or disturbances in the earth's magnetic field.

Meridian: A line of longitude, or half of one of the great circles that pass through the poles and cut the equator at right angles.

Mesophyte: A plant that requires a moderate amount of moisture. Most common trees and shrubs are mesophytes.

Mestizo: Offspring of a European and an American Indian-the term is used mostly in South America.

Monsoon: A type of wind system in which there is complete reversal or almost so, of prevailing wind direction from season to season.

Moraine: The debris or fragments of rock material brought down with the movement of glacier.

Mulatto: The offspring of a white and a black person commonly used in America.

Nivation: Erosion due to action of snow.

Nomadism: The practice, among certain primitive people, of frequently changing their habitation. These people keep moving residence in search of food and fresh pasture for animals. People following this mode of life are called nomads.

Oasis: Area in the desert where water is available.

Ocean Current: Movement of the surface water of the ocean.

Opisometer: Instrument used for measuring distances on a map.

Orbit: Path of a heavenly body through space in relation to some selected point.

Orographic rain: Rain caused by mountains standing in the path of moisture-laden winds.

Outwash Plain: Alluvial plain formed by streams originating from the melting ice of a glacier.

Pampas: The mid-latitude grasslands of South America.

Pastoralism: Practice of breeding and rearing cattle Some pastoral communities may be nomadic in their habits.

Pedology: The science of the study of soils.

Pelagic: Belonging to the open sea.

Peninsula: A stretch of land almost surrounded by water.

Perigee: The point in the orbit of moon or a planet or in the apparent orbit of the sun, nearest to the earth.

Permafrost: Ground that is permanently frozen.

Petrology: The study of the composition, structure and history of rocks forming the crust of the earth.

Phenology: Science dealing with the effects of seasonal changes upon animal and plant life.

Phytogeography: The study of the distribution of plants, on the earth, in relation to environment.

Piedmont: Belonging to or related to the foot of a mountain.

Planetary winds: The general distribution of winds throughout the lower atmosphere which is determined by differences in insolation and would be set up similarly on any rotating planet possessing an atmosphere.

Planimeter: Instrument for measuring irregular plane areas on maps.

Plateau: Extensive level or near level area of elevated land.

Playa (Spanish: shore or beach) Also called pan, flat, or dry lake, flat-bottom depression is found in interior desert basins and adjacent to coasts within arid and semiarid regions, periodically covered by water that slowly filtrates into the ground water system or evaporates into the atmosphere, causing the deposition of salt, sand and mud along the bottom and around the edges of the depression. Terminology is quite confused for playas because of many local names. A saline playa may be called a salt flat, salt marsh, salada, salar, salt pan, alkali flat or salina. A salt-free playa may be termed as clay pan, hard pan, dry lake bed or alkali flat. In Australia and South Africa small playas are generally referred to as pans. The low-relief plains of these lands contrast with the mountainous deserts of North America, resulting in numerous small pans insteadat immense playas. The terms takyr, sabkha, and kavir are applied in Central Asia, Saudi Arabia and Iran respectively,

Prairies: Mid-latitude grasslands of North America.

Precipitation: Falling water (in liquid or solid form, as tie case may be) from the atmosphere to the earth.

Pressure gradient: Rate at which pressure declines horizontally on the earth's surface.

Psychrometer: Instrument used for measuring humidity oi the atmosphere.

Rain shadow: Area having relatively lower average rainfall because it is sheltered from the prevailing rain-hearing winds by a range of mountains or hills.

Reef: Ridge of rocks lying near the surface of the sea, which may be visible at low tide, but usually covered by water.

Reg: A stony desert. A sandy desert is called an erg.

Rhumb line of loxodrome: Line on the earth's surface which cuts all meridians at the same angle.

Saprophyte: A plant which lives on decaying organic matter. Most such plants are fungi.

Satellite: A relatively small body revolving around a planet.

Savanna: An area of tropical grassland with scattered trees.

Seismic focus or deep focus: Point below the earth's surface where an earthquake originates.

Seismograph: Instrument used for measuring and recording earthquake shocks.

Seismology: Science of the study of earthquakes.

Selvas: Dense equatorial forests of the Amazon basin South America.

Sleet: Precipitation consisting of a mixture of snow and rain.

Smog: Fog heavily laden with smoke.

Snow-line: Lower limit of perpetual snow. The snow above this line does not melt completely even in summer.

Soil erosion: The wearing away and loss of soil mainly by the action of wind and water.

Solar constant: Intensity of the sun's radiation in space at the mean distance of the earth from the sun.

Steppe: Mid-latitude grasslands of Eurasia.

Strait: Narrow stretch of sea connecting two extensive areas of sea.

Syncline: Trough or inverted arch of a fold in rock strata.

Sublimation: Change of state of water from solid to vapour directly or vice-versa.

Taiga: Coniferous forestland of Siberia.

Temperature inversion: Condition when the temperature is found to be increasing instead of decreasing with height.

Theodolite: Instrument used for measuring angular distances in the vertical plane (elevation) and the horizontal plane (azimuth).

Thermograph: Self-recording thermometer-an instrument for measuring temperature.

Tidal range: Average difference in water level between high and low tide at one place.

Topographic map: Map on sufficiently large scale to show the detailed surface features of an area.

Tributary: Smaller river which joins a larger river.

Tropophyte: A plant which acts as hygrophyte in one season and xerophyte in the other.

Tsunami: A large sea wave caused by an earthquake originating on the sea bed.

Viticulture: The culture of grape-vine.

Volcano: Vent in the earth's crust caused by magma forcing its way to the surface through which molten or solid rock flow from the interior of the earth.

Watershed: Elevated boundary line separating headstreams which are tributaries to different river systems or basins.

Weathering: Decay and disintegration of rocks of the earth's crust by exposure to the atmosphere; it is one of the main processes of denudation.

Willy-willy: Tropical cyclone in the Pacific near the east coast of Australia.

Xerophyte: Plant which is adapted, to living in a region where little moisture (or dry climatic condition) is available.

Yazoo river: Tributary which is prevented from joining the main river because the latter has built up high natural levees; it thus runs parallel to the main stream for a considerable distance before joining it downstream.

Zenith: Point in the celestial sphere vertically above one's head.

Zodiac: Zone of the heavens in which lie the paths of the sun, the moon and the chief planets.

Zoophyte: An animal which resembles a plant, viz.—a coral polyp, a sponge.