Geographical Terms

A

abrasion Wearing of rock surfaces by friction, where abrasive material is transported by running water, ice, wind, waves, etc.

abrasion platform Coastal rock plat­form worn nearly smooth by abrasion.

absolute humidity Amount of water vapour per unit volume of air.

abyssal Ocean deeps between 1,200 and 3,000 fathoms, where sunlight does not penetrate and there is no plant life.

accessibility Nearness or centrality of one function or place to other functions or places measured in terms of distance, time, cost, etc.

acre-foot Amount of water required to cover I acre of land to depth of I ft. (43,560 cu. ft.).

adiabatic Relating to chan~e occurr­ing in temp. of a mass of gas, III ascend­ing or descending air masses, without actual gain or loss of heat from outside.

afforestation Deliberate planting of trees where none ever grew or where none have grown recently.

aftershock Vibration of earth's crust caused by minor adjustments of rocks after main earthquake waves have passed.

age-sex pyramid Graphical represen­tation of population structure showing number of males and females by age groups.

agglomerate Angular fragmented vol­canic material cemented together by heat.

agglomeration Large tract of essen­tially urban and industrial land result­ing from growth and physical expan­sion of formerly separate neighbouring settlements.

agronomy Agric. economy, including theory and practice of animal hus­bandry, crop production and soil management.

aiguille Prominent needle-shaped rock-peak, usually above snow-line and formed by frost action.

ait Small island in river or lake.

alfalfa Deep-rooted perennial plant, largely used as fodder-crop since its deep roots withstand drought. Pro­duced mainly in U.S.A. and Argentina.

allocation-location problem Problem of locating facilities, services, factories etc. in any area so that transport costs are minimized, thresholds are met and total population is served.

alluvial cone Form of alluvial fan, consisting of mass of thick coarse material.

alluvial fan Mass of sand or gravel deposited by stream where it leaves constricted course for main valley.

alluvium Sand, silt and gravel laid down by rivers, especially when in flood or when their velocity IS checked.

almwind Warm Fohn type wind, blowing s over Tatra Mountains into s Poland.

alp High summer pasture on shoulder of mountain , especially in Switzerland, where marked change of slope occurs above glaciated valley.

altocumulus Layer of fleecy cloud, at altitude of 8,000-20,000 ft. (2,380-6,096 metres) in groups or lines, often sign of good weather.

altostratus Mid-altitude cloud in form of extensive grey sheet, usually heralding rain associated with warm front.

627

A aluminium

aluminium Extracted from bauxite; metal of remarkable lightness, high strength and resistant to corrosion.

aluminum see aluminium

anabatic wind Local wind blowing up-valley in afternoon, when convec­tion currents on mountain slopes draw air upwards.

anemometer Instrument for measur­ing or recording force of wind.

aneroid barometer Instrument for measuring atmospheric pressure, com­prising metallic box, almost exhausted of air, whose flexible sides expand and contract with changing air pressure. Such movements are magnified and recorded on calibrated dial.

Antarctic Circle Parallel onat. 66°32' s, enclosing s Polar Regions.

anthracite Hard, shiny smokeless coal of high carbon content, producing great heat.

anticline Arch or crest of fold in rock strata.

anticyclone Area of high pressure with winds blowing clockwise round it in N hemisphere and anti-clockwise in s hemisphere. Moves slowly in tem­perate lat., with winds light or variable near centre. Produces fme settled weather in summer, but cold frosty weather or fog in winter.

antipodes Any two places on opposite sides of earth, so that line joining them passes through centre of earth.

apogee Part of orbit of moon or planet which is farthest from earth.

Appleton Layer Part of ionosphere, about 150 m. (240 km.) above earth, reflecting short radio-waves back to earth.

aqnifer Rock holding or allowing the passage of water.

archipelago (i) sea studded with islands; (iz) group of many islands, continental or oceanic.

628

Geographical Terms

Arctic Circle Parallel oflat. 66°32' N, enclosing N Polar Regions.

areal differentiation Differences bet­ween areas in terms of relief, climate, soils, vegetation, population, economy etc. Geography is often defmed as the study of areal differentiation.

arete Narrow ridge of spur or mountain, usually above snow-line and formed at crest between two cirques.

arroyo Small stream channel made by occasional rainfall in arid districts (Latin America, sw U.S.A.).

artesian basin Synclinal structure containing aquifer between two im­permeable beds.

artesian well Boring put down into aquifer in artesian basin; named from wells of this type in Artois, N France.

asbestos Fibrous mineral which can be spun and woven into material which is fire-proof, heat-resistant and of low conductivity.

asteroids Belts of small heavenly bodies revolving in Solar System bet­ween Mars and Jupiter.

Atlantic coast see discordant coast

atmosphere Envelope of air sur­rounding earth, consisting of 78% nitrogen, 21 % oxygen, very small quantities of carbon dioxide and other gases and varying quantities of water vapour.

atoll Circular or irregularly-shaped coral reef, partly submerged to enclose lagoon.

attrition Constant wearing-down of load of rock-material by friction when transported by running water, wind and waves.

aurora Luminous phenomena caused by electrical discharge and visible in sky in high lat.

avalanche Fall of mass of snow, ice or rock down mountainside and cap­able of great destruction.

Geographical Terms

axis (I) diameter between Nand s Poles, about which earth rotates; (i/) central line of fold from which strata dip or rise in opposing directions.

Ayala Strong, warm wind in Massif Central, France.

B

bad German, bath. Common prefix attached to German towns which are spas.

badlands High barren country in semi-arid regions with dry loose soils. Rain, when it falls, is heavy and washes out deep gullies so that little vegetation or animal life remains.

Bagnio Tropical storm of Philippine Islands, mainly occurring between July and Nov.

bahada Sloping expanse of scree, gravel and sand round margins of inland basin or at foot of mountains in semi-arid regions, formed by coales­cence of series of adjacent alluvial cones.

bajada see bahada

Bantu Native oftribe speaking one of 200 languages or dialects used in Africa s ofline Cameroon-L. Victoria.

bar (i) unit of atmospheric pressure equal to I m. dynes per sq. cm. At 45' N., in temp. ofO'C. at sea level, I bar= 29.53 ins. or750.1 mm. of mercury. It is divided into 1,000 millibars (mb.) for weather map purposes; (ii) ridge of sand and rock fragments across mouth of river or entrance to bay, see off-shore bar, tombolo; (iii) navigational obstruc­tion where alluvium, sand and gravel deposits occur in stream channels.

barchan Crescent-shaped sand dune

basalt B Awres high Sub-tropical anti­cyclone situated over E side OfN Atlan­tic, often extending to affect Britain and wEurope.

transverse to wind direction, with horns extending down-wind.

barkhan see barchan

barograph Self-recording aneroid barometer tracing ink line on moving drum.

barometer Instrument for measuring atmospheric pressure, also heights, and indicating weather changes. Common­est type employs column of liquid, usually mercury, in graduated tube. See also aneroid barometer

barrage Natural or artificial obstacle to flow of stream.

barrier lake L. produced by forma­tion of natural dam across valley, caused by landslides, avalanches, deltas, terminal moraines, or dams of vegetation, ice, lava or calcium car­bonate.

barrier reef (i) coral reef parallel to coast but separated from it by lagoon; (ii) coral reef wholly or partly enclosing coral island.

barrow Mound of earth or stones, covering anc. burial chamber, particu­larly common on chalk land of SE England.

barysphere Heavy central core of earth below lithosphere.

basalt Fine-grained, dark-coloured

629

B base-level

igneous rock, formed of solidifIed lava extruded by volcanic and fIssure erup­tions: flows readily to form extensive sheets and may solidifY to form hexago­nal columns.

base-level Lowest level to which stream can erode its bed. Permanent base-level is the sea, but lake may provide temporary base-level.

basic slag Blast-furnace by-product in iron smelting, contains phosphates and is crushed for fertilizers.

basin (i) large-scale depression occu­pied by ocean; (il) area ofland drained by single river system; (iii) area enclosed by higher land, with or with­out outlet to sea; (iv) part of dock system or canal ornavigable river.

batholith Very large intrusion of igneous rock, usually granite, originat­ing at great depth and extending over many miles. Upper surface may ulti­mately be exposed by erosion.

bathylith see batholith

bathyorography Map detail depict­ing altitude of land and depth of sea by layer-colouring.

bathysphere (I) central core of earth; (iz) diving apparatus used for submarine operations.

bauxite Impure aluminium hydrox­ide occurring widely in clay deposits, chief ore of aluminium.

bayou Marshy creek or sluggish back­water in lower Mississippi and along Gulf Coast ofU.S.A.

beach Accumulation of sand and shingle along coast, occupying space between low-water mark and highest point reached by storm waves.

bearing Horizontal angular direction of any place or object, taken from a fIxed point.

Beaufort scale Scale of wind forces ranging from 0 (calm) to 12 (hurri­cane). Introduced by Admiral Sir Francis Beaufort, 1805.

630

Geographical Terms

beck Small rapid stream.

bed-rock Solid rock of earth's surface, usually covered by soil or other super­fIcial deposits.

bedding Arrangement of rock strata in bands of varying thickness and character.

bedding-plane Structural feature of sedimentary rocks parallel to the original surface of deposition.

beet sugar Sugar from variety of beet grown in temperate zone; after sugar extraction, refuse, leaves and tops are pulped for cattle food, molasses and alcohol.

bench Narrow terrace, step or ledge produced by denudation, wave-cut bench, step-fault, or by mining and quarrying.

bench-mark Defmed and located point of reference used in triangulation survey.

berg German hill or mountain, Afri­can range. Also used in combinations for physical features, see bergschrund, Berg wind.

bergschrund Gap left round upper rim of snowfIeld or glacier as snow or ice moves downstream.

Berg wind Warm, dry Fohn wind, blowing mainly in winter from s Afri­can Plateau to coast.

bight (I) wide curve or recess of coast, often between headlands; (il) large bend of river.

bill Long narrow promontory.

billabong Backwater in temporary flowing stream in Australia.

Bise Cold, dry N or NE wind blowing in winter in Switzerland, N Italy and s France. Similar to Mistral or Tramon­tana.

bitumen Pitch or tar or asphalt.

bituminous coal Free-burning coal with high hydro-carbon content, includes most household and gas coals.

Geographical Terms

blackearth seechernozem

block mountain see horst

blow-hole Near-vertical cleft leading from sea-cave to cliff-top, formed by hydraulic action of wave-compressed air; spray is sometimes blown from it into air.

blow-out Hollow in sandy terrain formed by deflation (wind eddying), particularly where vegetation has been destroyed. In rock deserts, may develop from break in resistant surface layer.

bluff Headland formed by steep slopes bordering river or lake.

bocage Landscape ofNW France, with small fIelds enclosed by drystone walls or low banks with hedges.

Bohorok Hot dry wind on N coast of Sumatra during NW Monsoon (June­Sept.).

bolson Basin of interior drainage in arid or semi-arid regions. Floor may contain salt lake or alluvial fans round flanks of surrounding mountains.

Bora Violent, cold, dry wind blowing from N or NE into Adriatic, mostly in winter; can produce rain or snow when depression lies to the s.

Boraccia Particularly violent form of Bora.

bore Steep, wall-like wave in river with funnel-shaped estuaries, flowing rapidly upstream on rising tide. Highest at spring tides.

boreal (i) N; (ii) general term for clima­tic zone with short summers and snowy winters; (iii) climatic period from 7,500-5,500 B.C.

Borino Weaker summer form ofBora.

boss Small batholith, more or less cir­cular in plan.

Boswash Name given to the urban area extending from Boston (Massa­chusetts) to Washington (D.C.).

boulder cIay UnstratifIed glacial deposits of varying composition but

bund B usually consisting of clays, sand and stones of all shapes and sizes, probably representing ground moraine of ice­sheet.

bourne Temporary or intermittent stream flowing in dry valley of chalk country after period of heavy rain.

brachycephalic Broad Cephalic Index> 83.1.

headed.

brae Sloping bank or hillside (Scot.).

braided river channel Course of river split into complicated channels because of inability to transport its load.

brash ice Accumulation of crushed ice near shore, not thick enough to hindernavigation.

Brave West Winds see Roaring Forties

break in bulk Location at which materials or products are transferred from one mode of transport to another.

breaker Mass of broken water rushing up beach or where mass of rock lies near surface of sea.

breccia Angular fragments of rock of any type, cemented together in matrix.

breckland Area on borders of Norfolk and Suffolk comprising heathland, thicket and bracken.

Brickflelder Hot, dry, dusty, squally wind in SE Australia, caused by S move­ment of mass oftropical air, especially in summer.

British Summer Time Period in year during which clocks are advanced one hour ahead of Greenwich Mean Time.

broad Sheet of reed-fringed shallow water beside or forming part of sluggish river near estuary, particularly in E Anglia.

buffer state Small, independent autonomous country between two or more powerful ones.

bund (/) artifIcial embankment; (iI) main quay in some Far Eastern ports.

631

B Buran

Buran Cold, strong NE wind in Cent­ral Asia, producing blizzards in winter, but can also blow in summer.

burn Small stream (Scot.).

bush Large uncultivated tract, over­grown with bushes and small trees, usually in semi-arid regions.

bushveld Type of savanna in sub-

c

caatinga Thorn forest or open woodland with scrub in arid parts ofNEBrazil.

cacao Evergreen tree of equatorial or tropical regions, with large pods con­taining beans, the source of cocoa and chocolate.

caldera Large, shallow, circular cavity remaining after removal of former vol­canic peak by immense eruption; sometimes contains lake.

caliche Impure deposits of nitrogen salts found in deserts of Chile or Peru; valuable fertilizer in 19th cent.

campos (Plural) open plains of Cent­ral Brazil with savanna climate and vegetation.

cane sugar Tall tropical or sub-tropical plant whose stem yields sugar.

canyon Spanish, canon. (i) deep, steep-sided gorge with river at bottom, mainl y found in arid or semi-arid areas; (it) submarine trough on, and beyond, continental shelf.

'Cape Doctor' Strong wind blowing from plateau to coast in s Africa.

carr Fen containing reeds, shrubs and willows.

632

Geographical Terms

tropical and tropical Africa, with trees scattered, forming open parkland, but sometimes dense so as to resemble forest.

butte Isolated flat-topped hill, usually capped with resistant rock and rising abruptly from plain.

Buys Ballot's Law see Ferrel's Law

carse Level tract of fertile alluvial lands bordering estuaries in Scotland.

cartouche Panel on map, usually decorative, containing title, scale, etc.

cash crop Crop cultivated for market.

cassava Plant with tuberous roots, used as food in Central or s America.

caste Hindu hereditary social group.

cataract (I) waterfall running over sheer precipice; (it) series of rapids, as on R. Nile.

catch crop Quick-growing crop (I) bet­ween two main crops in a rotation; (it) between rows of main crop; (iit) in place offailed crop.

catchment Area served by a function, fIrm, establishment or central place.

catchment area Self-contained drain­age basin collecting all rainfall in area.

causses (I) French term used for lime­stone country in general; (it) limestone district in s of Massif Central, France, resembling Yugoslavian karst.

cavern Large cave or subterranean chamber, naturally produced, with

Geographical Terms

entrance, from surface; common feature of karst landscape.

cay Low island or reef of sand and coral in Caribbean Sea.

Celsius scale Internationally accepted name for Centigrade scale of temp. where 0' is melting point of ice and 100' boiling point of water, after inventor Anders Celsius (170 1-44).

Celtic fIeld Roughly sq. field, varying in size from half to one and a half acres, used before Saxons introduced strip­field system.

centrality Relative importance of a settlement with regard to region it serves.

central place A settlement providing goods, services, etc. for a surrounding area (catchment).

central place system Spatial distribu­tion of central places.

central place theory Theory of loca­tion of settlements and functions devised by W. Christaller (1933).

Cephalic Index Mathematical index to describe shape of skull = maximum breadth of skull -;. maximum length x 100. See also brachycephalic, dolicho­cephalic.

chaco Forest land in parts ofs Ameri­ca, see Gran Chaco.

chaparral Spanish, evergreen shrub vegetation ofNW America, resembling garigue and maquis of Mediterranean Europe.

chernozem Russian, 'Black Earth' soil of loose, crumbly texture, rich in humus and lime, covering large areas of temperate lands where natural vegeta­tion was grass, now forms great wheat growing areas of world.

chicle Gum obtained from latex of several trees in s and Central America, chiefingredient of chewing gum.

chili Hot, dry s wind over N Africa.

china clay see kaolin

climate C chine Narrow cleft in cliffs of soft material, containing stream; mainly found in Hampshire and Isle of Wight.

chinook American Indian 'snow­eater', dry, warm sw wind descending E slopes of Can. or N U.S.A. Rocky Mountains and warmed adiabatically; in spring, causes swift rise in temp.

chorochromatic map Map showing non-quantitative phenomena by means of colouring or shading.

choropleth map Map showing quanti­ties per unit of area by means of scaled shading or colouring (e.g. map of popu­lation density by parishes).

cinchona Tropical evergreen tree ofs America whose bark yields quinine.

cirque Steep-sided, flat-floored, horseshoe shaped rock-basin of glacial origin, marking site of cirque glacier, but in post-glacial conditions often contains smalf, deep lake.

cirro-cumulus 'Mackerel sky'; type of cloud above 20,000 ft. (6,096 metres), in lines of ripples, containing ice­crystals.

cirro-stratus Layer or veil of sheet cloud, above 20,000 ft. (6,096 metres), of milky appearance, causing sun or moon to appear with halo; marks approach of warm front.

cirrus Delicate, wispy clouds at 20,000-40,000 ft. (6,096-12,192 metres), containing ice-particles. When drawn out into 'mare's tail' indicates strong upper winds.

citrus fruit Obtained from evergreen trees like grape-fruit, lemon, lime and orange; widely grown in sub-tropical or warm temperate regions, especially Mediterranean climates.

cliff High, steep face of rock mass, especially along sea coast, where marine denudation is active.

climate Total complex of weather conditions, average characteristics and range of variation over large areas of earth's surface, considered over period of30-35 years.

633

C clinometer

clinometer Instrument for measuring vertical angle between two points or for measuring dip of strata.

clint Low, flat-topped ridge between fIssures or grikes on surface of carboni­ferous limestone plateau, forming limestone pavement as result of solution.

cloud Mass of condensed water vapour or ice-particles formed by con­densation on atmospheric nuclei, such as dust, smoke particles, pollen, etc. They float in masses from near ground level, as mist or fog, to over 40,000 ft. (12,192 metres).

c1use French for steep-sided valley cutting transversely across limestone ridges in Savoy Al ps and Jura.

coal measures Geological term cover­ing series of coal seams and intervening strata.

coast General name for zone of con­tact between land and sea.

coastline (I) general term for edge of land viewed from sea; (if) high-water mark of medi um tides; (iii) base of cliffs.

coca Bolivian shrub whose dried leaves provide stimulant when chewed.

cocoa see cacao

coconut Nut of palm from tropical regions of E Indies and PacifIc Islands whose dried flesh produces oil for margarine and soap; see copra

coffee Beverage produced from roast­ing beans of berries produced by trees in tropical uplands.

coir Outer covering of coconut used to make matting and cordage.

col (i) high pass between two higher summits; (if) area oflower pressure bet­ween two anticyclones.

cold front Rear of warm sector of depression, marking boundary between warm air and advancing wedge of cold air; undercutting causes appreciable temp. drop and heavy showers.

cold occlusion Where overtaking air

634

Geographical Terms

in occlusion is colder than air mass in front.

'Cold Pole' Term applied to point with lowest temp. usually referring to Verkhoyansk, NE Asia, where mean Jan. temp. is-58°F. (-50°C.).

collective farming Type of agric. organization started in U.S.S.R., but now practised in E Europe and SE Asia. Land compulsorily amalgamated into large holdings, run by manager and worked by directed labour; proportion of crops go to Govt., workers are paid a share of proceeds of marketing remainder.

Colombo Plan Formally put into operation in 1951 to improve political and economic conditions of sand SE Asia.

combe (I) Small, generally narrow valley; (if) glacial cirque, cwm.

common Area of land, often unen­closed, over which members of com­munity have certain rights of access, pasture, turf-cutting, etc.

compass Instrument used to deter­mine direction, either by free-swinging magnetized needle or by rotating gyro­wheel.

concordant coast Running parallel to general grain of relief, giving straight and regular coastline.

condensation Process whereby sub­stance changes from vapour to liquid, as with cloud formation, mist, etc.

condominium Territory governed jointly by two or more countries.

cone Volcanic peak with broad base tapering to summit.

confluence Point where trib. joins main stream.

conglomerate Rock composed of rounded, water-worn pebbles cement­ed together in matrix.

connectivity A measure of the number of routes connecting one place with other places.

Geographical Terms

continent (I) large, continuous mass of land; (il) mainland, as applied to Europe.

continental climate Climate of con­tinental interiors in temperate zone, with seasonal extremes of temp. and low rainfall, mainly in summer.

continental drift Theory that con­tinental masses have changed relative positions. First put forward in 19th cent. and now further substantiated through palaeomagnetism.

continental island One rising from continental shelf and structurally relat­ed to that continent.

continental shelf Gently sloping mar­gins of continent, submerged beneath sea and extending to point where con­tinental slope begins; in general less than 100 fathoms deep.

continental slope Steep slope des­cending from continental shelf to abyssal plain.

contour lines Lines on map connect­ing all points at same relative elevation above or below specific datum, usually sea-level.

contour ploughing Measure to combat soil erosIOn by ploughing along slope to reduce run-off.

conurbation Area of extensive urban development where existing separate towns have expanded so as to coalesce.

convection Transmission of heat through liquids and gases by move­ments of their particles .•

convectional rain Caused by mois­ture-laden air being warmed, rising, expanding and cooling adiabatically to its dew-point.

coombe see combe

copra Dried flesh of coconut, source of coconut oil, shredded coconut and cattle food.

coral Hard, calcareous substance formed from skeletons of some marine polyps living in warm inter-tropical seas.

crag and tail C coral reef Reef composed of coral limestone, see atoll, barrier reef.

cordillera Mountain system compris­ing several ranges, broadly parallel in trend.

core Central mass of earth, radius about 2,160 m. (3,456 km.), probably consisting of metallic mass of nickel­iron ornife.

Coriolis Force see Ferrel's Law

corona (I) series of coloured rings surrounding sun or moon resulting from diffraction of light by water drop­lets; (i/) fringe of radiant light visible round circumference of sun at total eclipse.

corrasion Frictional wearing down of rock surface by material moved by gravity, running water, ice, wind and waves.

corrie see cirque

corrosion Chemical solution of rock by water.

cOte (I) escarpment in France; (i/) section of coast (France).

coteau Name given by French ex­plorers in N America to sharp ridge of hills or prominent escarpment.

cotton Annual, sub-tropical shrub whose bolls contain fibrous material used to make cotton cloth; seeds are crushed for oil, cooking fat, margarine and cattle food.

cove (I) small creek or inlet or rounded bay; (i/) steep-walled, semi-circular opening at head of valley.

cover crop Quick-maturing crop ploughed In as fertilizer or grown as protective mat between main crops to reduce soil erosion.

crag and tail Characteristic of glaciat­ed area, where mass of resistant rock in path of advancing ice has been attacked on upstream side, to produce crag, but has I?rotected land on downstream side, leaVing a gentler slope or tail, to lee­ward.

635

C crater

crater (I) rounded, funnel-shaped hollow at summit of volcano; (il) depression caused by impact of meteorite.

creep Slow downward movement of soil under influence of gravity, lubricat­ed by running water.

Creole Person born in w Indies but not of aboriginal descent; initially implying no question of colour, now mainly descnbes people of mixed blood.

crevasse Deep fissure in glacier, with transverse trend where slope increases or longitudinal where glacier spreads out as valley widens.

croft Small farm-holding in Scotland, reckoned to supply all family's needs in food, fuel and clothing.

cromlech Celtic fonn of megalithic burial chamber, with large flat stone resting on stone uprights.

crust Upper (sial) and lower (sima) layers of earth, fonning outennost shell or lithosphere, about 10-30 m. (16-48 km.) thick.

D

dale Wide, open valley, particularly in N England.

Dalmatian coast see concordant coast

Date Line see International Date Line

datum Zero from which altitudes and depths are detennined; see ordnance datum.

deflation Removal of fine deposits of dust and sand from earth's surface by wind.

delta Alluvial tract fonning at mouth

636

Geographical Terms

cuesta Ridge with steep scarp slope and gentle dip slope, see escarpment.

comec Unit for measuring river dis­cha~e; number of cu. m. per second passmg particular point, approx. 19m. gallons per day.

comula-nimbus Cumulus cloud developing to immense vertical height with towering summits, sometimes s{>reading into anvil shape, and ass0-ciated with thunderstorms, hail and heavy rain.

cumulus Convectional cloud, growing vertically from flat base to produce white domed summits, often reaching 25,000 ft. (7,620 metres).

cutoff Channel cut by river across neck ofland at acute meander, leaving oxbow.

cwm see combe

cyclone Tropical low pressure system, Similar to depression of temperate lat. but smaller in extent and more violent in effect, marked by very high winds, torrential rain and thunder.

of river where deposition of part of river load exceeds rate of removal by tidal or other currents; covered by network of branching channels or distributaries.

demersal fish Species living near bottom of shallow seas, caught by trawling.

demography Branch ofanthropology, dealing with statistics of births, deaths, etc.

denudation Destructive process modifying surface of earth by all natural agencies.

Geographical Terms

deposition The laying down of mater­ial transported by all agencies; comple­mentary to denudation.

depression (I) low-lying portion of earth's surface; (il) low-pressure system in mid or high lat., formerly called cyclone, now known as cyclonic depression or 'low'; has diameter of 300-2,000 m. (480-3,200 km.) with winds blowing round it anti-clockwise in N hemisphere and clockwise in s. See fronts, occlusion.

desert Area ofland with scanty vege­tation and low rainfall or low temp. Types of desert include (I) hot, Trade Wind; (il) coastal, in lat. 15"-30·, with cool offshore currents; (iiI) mid-Iat. of continental interiors; (iv) polar.

determinism Philosophy that man's actions are essentially determined by physical condition of his environment.

detritus Material shed from rock sur­faces by disintegration.

dew Condensed droplets from atmos­pheric vapour on surfaces cooled by nocturnal radiation.

dew-point Lowest temp, to which air can be cooled without causing conden­sation.

dew-pond Small hollow of special construction to collect water from atmospheric condensation.

dike seedyke

dip-slope Gentle slope of cuesta.

discordant Cutting across general lines of structure ofland.

discordant coast Running transverse to general grain of relief, giving dissect­ed coastline.

dispersed city Group oflarge towns of similar size found in close proximity to each other, and tending to function m a complementary manner. Although the total population contained in its area is sufficient to support one large centre offering a full range of highest order goods and services, such a centre does not exist and these functions are shared between the constituent centres.

dustbowl D dispersed settlement Scattered farms and hamlets, with no concentration of population in village or larger settle­ment.

distributary Individual channel into which river may divide in delta, leading to sea without rejoining main stream.

diurnal range Difference in 24 hour period between maximum and mini­mum value of element such as temp.

Doctor Popular name for Harmattan wind, West Africa.

doldrums Equatorial belt oflow pres­sure between two Trade Wind belts, marked by light winds or calms, high temp. and humidity.

dolichocephalic Long headed. Cepha­licIndex < 75.

doline Shallow, saucer-shaped depression in karst landscape.

drainage (I) act of removing water from poorly-drained area; (il) discharge of water from any area through natural stream systems.

drift (I) superficial deposits, usually glacial; (il) horizontal passage in mine following vein of ore; (iiI) slow move­ment of surface ocean water under influence of prevailing winds; (iv) sur­face movement of loose material by wind, such as snow.

drumlin Low, oval-shaped hill of glacial origin, formed of boulder clay and elongated in direction of ice flow.

dry farming Agric. in semi-arid parts, without irrigation, where moisture is conserved by mulching, maintenance of fme tilth and croppmg in alternate years so as to increase total water.

dry valley Valley, usually in chalk or limestone, with no permanent flowing stream.

dunes Low ridges of wind-blown sand, found in deserts and along low­lying coasts above high water mark.

dust bowl Originally applied to parts ofsw and w U.S.A., but now refers to

637

D dust devil

any area where soil erosion occurs as result of over-grazing or over-cropping.

dust devil Short-lived swirling wind resulting from convection over sandy area, lifting dust and sand but not to any great height.

dust storm Caused by winds in semi-

E

eagre see bore

earth pillar Column of soft earth, often 20-30 ft. (6-9 metres) high, pro­tected by capping of rock; product of sub-aerial erosion.

earthquake Movement or tremor of earth's crust causing series of shock waves to move outwards in all directions.

eclipse Partial or total obscuring of light of (I) moon, when earth comes between it and sun; (i/) sun, when moon comes between it and earth.

ecliptic Apparent movement of sun through sky during course of year; plane of ecliptic is tilted at angle of about 66lho to earth's axis.

entrepOt Centre or port to which goods in transit are sent for temporary storge before re-export.

environmentalism Philoso{,hy that environmental factors determme man's actions see determinism.

environmental perception The en­vironment as perceived by individuals or groups rather than as it is in reality.

epicentre Point on earth's surface vertically above origin of earthquake shock.

638

Geographical Terms

arid areas causing dense clouds of dust to rise to considerable heights.

drke (I) mass of intrusive rock run­nm~ discordantly across landscape; (i/) dramage ditch or watercourse; (iiI) arti­ficial embankment preventing flooding of low ~ound; (iv) embankment in flood plam of river parallel to its course; (v) man-made defensive earthwork.

equator Great circle, lat. 00, midway

between Poles, in plane perpendicular to earth's axis.

equinox Period of year when day and night are of equal length all over world, occurring about March 21 and Sept. 23, when sun crosses equator.

erg Arabic for sandy deserts of Sahara with dunes and sand-sheets.

erosion Wearing away of land sur­faces by various natural agents, chiefly running water, ice, wind and waves but, unlike denudation, excludes weather­ing.

erratic block Piece of rock carried by glacier or ice-sheet and deposited some distance from parent outcrop when ice melted.

escarpment (I) see cuesta; (il) term also applied to any steep slope breaking general uniformity oflandscape.

esker Elongated ridge or mound formed from glacial and sub-glacial sands and gravels, deposited by sub­glacial streams.

esparto Grasses grown in N Africa and Iberian Peninsula, used in making paper, cordage, matting and sacks.

estancia Spanish, large farm in

Geographical Terms

Argentina used for extensive cattle rearing.

estuary Mouth of river where channel broadens into V -shape and tidal move­ments occur.

etang French, shallow lake in sand­dune areas, formed by beach material thrown up by sea.

Etesian wind Strong N to NW wind at intervals in summer in E Mediterra­nean.

eucalyptus Gum tree of Australia.

eustasy World-wide change of sea level, caused by Ice Age, movement of ocean floors or sedimentation of ocean basins.

evaporation Physical process by which substance changes from liquid to vapour state, caused mainly by heat.

everglades Marshy area with grasses

F

Fahrenheit Graduated scale of temp. where 320 is melting point of ice and 2120 boiling point of water, after A. D. Fahrenheit (1686-1736).

fall-line Narrow belt, marked by line of waterfalls, where rivers descend from plateau edge to lowland, as in Fall Line mSEU.S.A.

fan Fine wind- or water-borne material, deposited in shape offan with low angle of slope.

fathom Nautical measurement of depth, equal to 6 ft. (1.9 metres); 1,000 fathoms equal I nautical m.

fault Fracture or rupture in earth's crust, where movement has displaced strata on each side.

fetch F and trees in Florida and along Gulf Coast ofU .S.A.

exfoliation Alternate heating and cooling of rock surfaces causing peeling offin scales.

expanded town Town outside the metropolitan area whose expansion has been purposefully accelerated by Government agencies (e.g. by fmancial assistance towards development of industries, housing) to curtail further expansion of metropolitan regions and to alleviate over-crowding elsewhere (e.g. Basingstoke).

extensive agriculture Method off arm­ing based on large farm units with little labour but with a high degree of mechanization (e.g. Canadian Wheat­lands).

extrusive rocks Igneous rocks reach­ing the surface as lava, flowing from fissures and then solidifying.

eyot seeait

fauna Animal life of region or geologi­cal period.

fell Norwegian, bare, uncultivated hill or mountain in N England.

fen Water-logged land of reed and peat, providing excellent agric. land when drained, as in Fens OfE Anglia.

Ferrel's Law Postulated by American scientist W. Ferrel in 1856, stating that bodies in free motion are deflected to right in N hemisphere and to left in S, (Coriolis Force) as result of earth's rotation.

fetch Extent of open water over which wind blows, instrumental in determin­ing height and force of waves.

639

F [lard

flard Swedish fjard; large open area of water, surrounded by islands, occurring in rocky, glaciated lowlands.

fiord Norwegian fjord; drowned glacial valley, being long and narrow, steep-sided and deep, apart from thres­hold near mouth.

liro German, snow accumulating in layers above glacier, partially compact­ed by freeze and thaw action.

flrth Estuary or strait or arm of sea (Scotland).

fjard see liard

fjord see liord

flash-flood Sudden, short-lived torrent in semi-arid areas after inten­sive rainfall, carrying large load, product of desert weathering.

flax Annual plant, yielding fibre for linen and seed for linseed oil, paint and cattle-cake.

fleet (I) small inlet or lagoon of brack­ish water behind coastline, separated from it by sand or shingle bank; (il) small creek or inlet.

flood-plain Hoor of river valley over which alluvium is spread in flood time.

flora Plant life of region or geological period.

flume (I) narrow ravine or gorge; (i/) artificial channel to provide water for power or to float logs.

fluvio-glacial Effects of melt-water stream issuing from glacier-front or ice­sheet margin.

fog Thick mist or haze in surface layer of atmosphere resulting from conden­sation of moisture with smoke and dust particles in suspension; visibility less thanO.6m.(1 km.).

640

Geographical Terms

FOhn German, warm, dry, adiabatic wind blowing down lee slopes of mountains, especially in Alps, when depression to N draws in air from Mediterranean.

fold Bending of strata by compressive forces in earth's crust, usually along lines of weakness.

force Waterfall in N England.

foreshore Part of shore lying between high and low-water line of mean spring tides.

fosse (I) ditch or trench round anc. earthwork; (iI) waterfall in N England, see force; (iiI) in U.S.A., depression bet­ween valley-glacier side and valley wall.

free port Port where goods can be unloaded, held in bond and re-exported without customs payments.

Friagem Strong, cold winter wind on campos ofBrazii and E Bolivia.

fringing reef Uneven coral platform attached to coast, with or without lagoon intervening, sloping steeply seawards.

front Plane of separation between warm and cold air masses.

frost (I) condition of air whose temp. is at or below freezing point of water; (i/) minute crystals of ice formed from water vapour when dewpoint is below freezing.

frost-pocket Low-lying area into which cold air drains by gravity to produce freezing conditions when air on higher slopes is still above freezing; fruit-growers avoid such areas.

fumarole Italian, small vent in surface, pouring forth steam, hydro­chloric acid, sulphur dioxide and other gases.

G

gap see water gap, wind gap

garrigue French, stunted evergreen scrub separated by bare limestone rock, found in s France, Corsica, Sardinia and Malta.

geest German, area of coarse sand, gravel and heath vegetation in N Ger­many, Netherlands, Denmark and Poland.

geo Norse gya, a creek; long, narrow, steep-sided inlet in cliff, derives origin­ally from cave enlarged by marine erosion.

geosyncline Linear depression in earth's crust, of considerable width and several m. deep, product of slow, con­tinuous down-warping of ocean floor, accompanied by sedimentation of material worn away from neighbouring land masses.

geyser Icelandic geysir, '~sher' or 'roarer'; hot spring ejectm~ super heated steam and hot water at mtervals from volcanic sources.

ghat Indian, (I) river landing place; (i/) mountain pass; (iii) range of mountains.

ghaut see ghat

ghee Hindu, butter made from buffalo milk.

ghetto Part of urban area inhabited almost exclusively by one race or type of people.

Ghibli Arabic, hot, dry, s sirocco wind of Libya or Tunisia.

Gibli seeGhibli

glacier French, mass of compacted snow and ice, accumulated on ground above snow-line, moving downstream under gravity and exerting great erosive force.

glacio-fluvial see Fluvio-glacial

glen Long valley, steep-sided and flat­bottomed (Scotland).

gneiss rock.

Coarse-grained crystalline

Gondwanaland Hypothetic single land-mass in anc. geological times, from which present s continents were formed as outcome of continental drift.

gorge Steep-sided valley, deep in rela­tion to width.

graben German, narrow fault-trough.

Gran Chaco 'Great hunting ground', forest or savanna region on borders of Bolivia and Paraguay.

f!I"lISslands Region where rainfall is msuffIcient for tree growth but is less scanty and irregular than in desert regions; major types include tropical or savanna, temperate or steppe or prairie or pampas or veld, and mountain.

graticule Network of parallels and meridians drawn on map or globe.

great circle Circle on earth's surface whose plane passes through centre of earth; arc of great circle provides shortest distance between any two points on earth's surface.

Green Belt Planned and maintained wne of open country round town or separating adjacent towns, free from building or industrial development.

Greenwich Mean Time Standard time for British Isles and parts of w Europe, see British Summer Time

Greenwich Meridian Prime meri­dian, passing through old Royal Obser­vatory at Greenwich; long. ofa place is expressed E or w ofthis, up to 180·.

641

G Gregale

Gregale N cool-season winds of Cent­ral Mediterranean.

greywether Scattered blocks of sand­stone found over parts of chalklands of S England, so-called because of their resemblance to sheep.

grid Network of sq. covering map series, based on lines drawn parallel and at right angles to central axIS, from which position of any point can be stated; see National Grid

grike Deep groove, bounded by ridges or clints in area of karst landscape, where limestone pavement results from solution.

ground moraine Debris carried at base of glacier or ice-sheet and deposited as ice melts.

groundnut Tropical or sub-tropical

H

haar Summer sea-fog blowing onto E coast ofN England and Scotland.

hachure Lines of shading on relief map to show differences in slope.

hacienda Spanish, large a~c. estate, ranch or plantation, chiefly in s America.

haff German, shallow, fresh-water lagoon, formed by growth of spit or nehrung across river mouth, notably in Baltic.

hamada Arabic, rock desert of N Africa, Australia, Gobi.

hanging valley Trib. entering main valley from considerable height, often with waterfalls; common in glaciated regions, where main valley has been over-deepened by glacier.

642

Geographical Terms

plant whose pods ripen below ground; when crushed, these produce oil for margarine, cooking fat, other foodstuffs and animal fodder.

ground water Body of water contained In soil, subsoil and underlying rocks above impermeable layer.

gryke see grike

guano Accumulation of bird drop­pin~ forming valuable phosphatic fertilizer.

Gulf Stream Warm ocean current flowing NE from Gulf of Mexico towards Europe; see North Atlantic Drift

RUlley erosion Accelerated erosion of rand by concentrated surface run-off after sudden rainstorm; major cause of soil erosion.

Manse Towns Political and commer­cialleague of Germanic towns.

Harmattan Hot, dry NE wind, blowing off Sahara to w African coast in Dec.-Feb. providing relief from humi­dity on coastal plain, but dry and dusty inland.

haze Obscurity in atmosphere caused by condensation of moisture on dust or salt or smoke particles or by heat refrac­tion; visibility from I to 2 m. (1.5-3 km.).

headland Steep crag or cliff projecting into sea.

head of navigation Farthest point up­river reached by trading vessels.

Heaviside Layer Section of iono­sphere, 60-75 m. (96-120 km.) high,

Geographical Terms

highly ionized and able to reflect long radio-waves back to earth.

Helm Strong, cold E to NE wind blow­ing off Pennines in N England.

hemp Fibre-producing plant, for twine, string, rope, matting etc. whose flowers and leaves produce drugs and whose seeds yield oil.

Hevea Brasiliensis Tree, native to equatorial forests of Brazil, now grown in plantations in Malaysia or E Indies; source of commercial rubber; see latex

hinterland (I) 'back country' of early coastal settlement; (il) area served by port, taking its imports and supplying it with its exports.

hoar-frost Thin deposit of ice crystals on surface cooled below freezing point by radiation.

hook Sand bar ending in recurved spit.

horizon (I) visible horizon, boundary of earth's surface, as viewed from point where sky appears to meet earth or sea; (il) true horizon, great circle whose plane passes through centre of earth and is parallel to visible horizon; (iiI) geological horizon, plane of stratified surface or bed; (ic) soil horizon, main layer or zone within soil profile.

hom German, pyramid peak formed by development of back-to-back cirques on mountainside.

I

iceberg Large mass of floating ice, broken off from edge of ice-sheet or tongue of tidal glacier and floating under influence of currents and winds;

ice-cap I horse latitudes Sub-tropical high pressure belts of atmosphere, over oceans in lat. 30-35°, giving calm con­ditions and stable weather.

horst German, block of earth's crust (I) left standing after adjacent areas have sunk by faulting; (il) uplifted between faults.

hot springs seethermalsprings

Humboldt Current Cool ocean cur­rent flowing N along w coast of s America.

humidity State of atmosphere with regard to water vapour it contains; see absolute humidity, relative humidity

humus Vegetable mould derived from decomposing organic matter in soil.

hurricane (I) tropical revolving storm with violent cyclonic winds in Carib­bean Sea and off Queensland coast; (b) wind of Force 12 on Beaufort Scale.

hydro-eiectric power Electrical energy obtained by harnessing water­falls or by damming river.

hydrological cycle Endless inter­change of water between sea, air and land, by evaporation, condensation, precipitation, etc.

hygrometer Instrument for measuring relative humidity of air.

those in N hemisphere mainly irrigular in shape, those in s are tabular.

ice-cap Permanent mass of ice,

643

I icefall

smaller than ice-sheet, covering plateaus and high-lat. islands.

icefall Heavily crevassed part of glacier where it meets change of slope of valley floor.

ice-field Large, continuous area of pack-ice.

ice-sheet Mass of permanent ice and snow of great thickness, covering large areas, as in Antarctica and Greenland; also refers to much greater areas in past glacial eras.

ideographic Studying individual cases and situations; opposite nomothetic.

igneous rock One formed by solidifi­cation of molten rock or magma; see extrusive and intrusive rocks

incised meander Pattern of meander maintained at progressively lower levels by downcutting of river resulting from rejuvenation.

industrial inertia Condition whereby industries, once established at a central location, remain there due to existing investment in capital, services, etc., even though some other location may ultimately appear more attractive in terms of certain other criteria.

infield Farmland immediately sur­rounding a farm or hamlet farmed intensively. See also outfield.

input-output analysis Analysis of the flows of goods or services, usually in terms of their cash value, which take place between all sectors of a regional economy. Often used to predict the overall effect of changes in the regional economy.

inselberg German, mountain rising abruptly from uniformly level surface, esp. in semi-arid and arid climates.

insolation Amount of radiant solar energy reaching earth's surface.

interOuve Area of land between two rivers.

interlocking spurs Alternate project-

644

Geographical Terms

ing spurs in upland valley where river follows winding course.

International Date Line Imaginary line closely following 180· meridian, where date changes by one day as it is crossed, to make up for cumulative effect of time zone changes; westbound travellers lose a day, eastbound ones gain a day.

intrusive rocks (I) those resulting from injection of magma into existing rocks; (ii) particular type of igneous rock thus formed; see batholith, dyke, laccolith, sill.

ionosphere Part of atmosphere above stratosphere, marked by distinctive layers reflecting electromagnetic waves; see Appleton Layer, Heaviside Layer

irrigation Artificial application of water to land in arid regions to promote plant growth.

island Piece of land, smaller than continent, surrounded by water.

isobar Line on map joining points of equal atmospheric pressure; figures reduced to sea-level for comparison.

isobath Line on map or chart joining submarine points of equal depth.

isochrone Line on a map joinin~ all places of equal travel time from a given point.

isohyet Line on map joining points having same rainfall over given period.

isoneph Line on map joining points having same amount of cloudiness.

isopleth Line on map joining points having same value for particular phenomena, see isobar, etc.

isostasy State of equilibrium in sur­face crust of earth, whereby equal mass underlies equal surface area.

isotherm Line on map or chart join­ing points having same air or sea temp.

isotropic surface A theoretical area of broad, featureless plain on which trans­port is equally available in all direc­tions, population is uniformly distri­buted and has uniform tastes and

Geographical Terms

preferences. Used as a basic assumption m many locational theories (such as central place theory).

J

jarrah Eucalyptus tree ofsw Austra­lia, resembling mahogany and very durable in water.

jet stream Hi~ altitude air move­ment of strong wmds in narrow belt.

joint Plane of division in rock mass, usually transverse to bedding-plane, caused by tension or compression.

K

kame Hummocky deposits of sand and gravel laid down by melt-water along edge of ice-sheet, usually parallel to ice-front.

kaolin Hydrated silicate of alumina derived mamly from decomposed gran­ites; known as china clay, used in manu. of pottery, china and paper.

Karaburan Hot NE wind in Central Asia, sweeping up clouds of sand, the lighter particles being carried great dis­tances and ultimately deposited as loess.

karri w Australian eucalyptus, pro­viding very hard timber.

karst Italian, carso, Serbo-Croat,

key K isthmus Narrow neck ofland between two seas or joining peninsula to main­land.

joran Cold, dry wind blowing at night from Jura Mountains to L. Geneva.

jungle Wild, uncultivated land; now widely used to refer to tropical forest with dense undergrowth.

jute Fibre from bark of plant grown in Bengal and used in making sacks, carpets, etc.

kars; proper name for rugged limestone plateau of NW Yugoslavia, but used generally to describe areas of carboni­ferous lImestone with typical pheno­mena of limestone pavements, sink holes, underground drainage, caverns, gorges, etc.

katabatic wind Cold wind, blowing downhill, usually at night, caused by gravity flow of dense air from upper slopes, chilled by radiation.

kay seecay

kettle hole Circular hollow in glacial drift, caused by melting oflarge block of ice separated from glacier.

key seecay

645

K Khamsin

Khamsin Arabic, hot, dry, sirocco wind of Egypt and SE Mediterranean.

kloof Afrikaans, deep, narrow ravine or mountain pass in S Africa.

knot (I) nautical measurement of speed, 1 nautical m. per hour; (il) junction of two or more ridges in fold mountain system.

L

labour coefficient Ratio of labour cost to all other inputs or outputs of productive process.

laccolith Intrusive mass of magma forced up a pipe and spreading laterally in lenticular form, causing arching of the overlying strata.

lacustrine Pertaining to a lake.

ladang Slash and bum shifting agric. practised in SE Asia.

lagoon (I) sheet of salt water separated from open sea by sand or single bank; (il) sheet of water between off-shore reef and mainland; (iiI) sheet of water within an atoll.

lake Extensive sheet of water enclosed by land, occupying hollow in earth's surface.

land and sea breezes Resulting from unequal heating of land and water masses. By day, with land heated more rapidly, sea-breeze blows on-shore; by night, land-breeze blows off-shore as land loses heat by radiation.

landes French, wastelands; proper name of lowlands of sand-dunes and lagoons in sw France.

lapies French, bare limestone surface

646

Geographical Terms

kopje Afrikaans, prominent, small, isolated hill in s Africa.

kraal Afrikaans, village, cattle-pen or enclosure in Africa, surrounded by thorn fence.

kyle Gaelic, channel or sound or strait between mainland and island or between two islands.

with joints widened by solution to form c1ints and grikes.

lapse-rate Rate of temp. decrease in atmosphere with increase in height. Environmental lapse-rate approx. -21°F. (6"e.) per 3,250 ft. (1,000 metres).

laterite Red soil consisting of decom­posed and weathered igneous rocks, found as soil horizon in tropical climates.

latex Milky fluid of rubber tree (Hevea Brasiliensis), extracted by tap­ping bark to provide raw matenal for manu. natural rubber.

latitude Angular distance N or s of Equator of any poiht along a meridian.

lava Molten rock or magma extruded onto surface of earth and subsequently solidifYing.

leaching Removal of soluble salts from upper layers of soil by water per­colation in humid climates.

least cost location Location at which costs of production of any economic activity are at a minimum compared with costs at all other possible locations.

Geographical Terms

Levanter Spanish, mild and humid E wind affecting SE Spain, Balearics and Straits of Gibraltar when depressions form in w Mediterranean.

Leveche Spanish, hot, dry S wind blowing from Morocco to Spain when E-moving depressions enter Mediter­ranean.

levee (I) broad low ridge of alluvium built up by river in flood to form bank; (il) artificial embankment along river to check flooding.

ley Area of cultivated grass or clover in an arable rotation.

liana Climbing plant, rooted in ground, usually in tropical forests.

libeccio Italian, strong w wind of Corsica, most frequent in summer.

light-year Distance light travels in I year at rate of 186,326 m. (298,123 km.) per second, i.e. approximately 5,878,310,400,000 m. (9,405,296,000,000 km.).

lignite Low-grade type of coal, midway between peat and sub­bituminous coal in carbon content, mainly used in thermal-electric genera­tors.

limestone pavement see clint

limon French, superfIcial deposit of fme material, often wind-blown and resembling loess, found in Belgium and the Paris Basin.

lithosphere Solid crust of earth.

littoral (I) relating to sea-shore; (i/)

lynchet L zone between high and low water marks.

llanos Spanish, tropical grasslands or savanna of Guiana Plateau, S America.

load Material transported by natural agent as part of denudation process, but applied mostly to river.

loam Soil consisting of a friable, permeable mixture of clay, sand and humus.

locational analysis Analysis of the location of human and economic activity.

location theory Attempt to isolate and analyse theoretically those factors which influence the location of econo­micactivity.

loch Scottish, lake or long narrow arm of sea.

loess German, fme-grained, friable, porous dust, usually removed from arid regions by wind and deposited fmally in broad sheets, as in Asia, Central Europe and N America.

longitude Angular distance of a place E orw of prime meridian.

longitudinal coast see concordant coast

longshore drift Drift of material along a beach as result of waves breaking at angie to shore.

lough (Irish), see loch

lucerne see alfalfa

lyncl!et Man-made terrace on hill­side, parallel to contours, part of anc. cultivation practice.

647

M

maelstrom Dutch (I) whirlpool; (ii) powerful eddy in tidal current in restricted channel, as Maelstrom in Lofoten Islands, Norway.

Maestrale (Italian) see Mistral

magma Molten material under earth's crust, from which igneous rocks are formed.

magnetic pole Two extremities of earth's magnetic fiC;ld, lying in polar regions, indicated by free-swinging magnetic needle in compass.

maize Cereal crop, originating in New World, grown in sub-tropical and warm temperate climates, mainly used to fatten livestock; known as corn in U.SA

mallee Dense scrubby growth of dwarf eucalyptus in SE and sw Aust­ralia.

mangrove Tree with short trunk and maze of aerial roots, forming almost impenetrable obstacle. Mangrove swamps are found mainly in tropical and sub-tropical regions, close to river -mouths.

manila hemp Plant grown largely in Philippines for its fibre, used in making rope and fabrics.

manioc see cassava

mantle (I) layer ofi~eous rock, some 1,800 m. (2,880 km.) thick, lying bet­ween crust and core of earth; (i/) surface accumulation of soil and weathered rock, or regolith.

maquis French, low scrub ofMediter­ranean area, characterized by dense xerophytic vegetation, found mainly in S France, Italy (macchia) and Corsica.

marin Moist, warm SE wind over coast ofs France in spring and autumn when depressions enter Gulf of Lyons.

648

marine terrace Shoreline above pre­sent sea-level.

marketing principle Theoretical spatial arrangement of settlements, sug­gested by W. Christaller (1933), where­by the supply of goods from central places to other settlements involves the least transport cost.

market location Location chosen by firm, industry etc. which is nearer to its major market(s) than to its raw mater­ials, suppliers, etc.

marl (I) mixture of clay and calcium­carbonate; (i/) geological name of parti­cular types o( rock.

massif French, (I) compact mount­ainous area with relatively uniform characteristics and clearly defmed mar­gins; (i/) mountain group, as Mont Blanc massif.

mate tea Made from dried leaves of S American evergreen shrub.

meander Curve in course of river moving slowly across flat country.

Mediterranean climate Warm tem­perate climate ofw margins of contin­ents in lat. 30-40° , with hot, dry, sunny summers and mild, moist winters.

megalith Large stone or stones, erected singly or in circles as monu­ments, mainly Neolithic.

megalopolis Very large urbanized metropolitan area. Orisinally applied to the Boston-Washmgton region U.S.A. see also Boswash.

Melanesia Group of islands in w Pacific.

melt-water Water formed from melt­ing snow or ice, as in melt-water stream of glacier.

Geographical Terms

menhir Single upright stone of Neo­lithic origin, marking burial place.

Mercator projection Cylindrical pro­jection used by German Mercator for world map of 1569. Meridians oflong. and parallels of lat. are all shown as straight lines, causing distortion of shape in high lat.

mere Small lake usually circular, common in Cheshire where removal of underground salt deposits causes subsi­dence.

meridian Line of long. part of Great Circle. Prime Meridian IS Greenwich Meridian (0°).

merino Sheep with long-stapled, high-quality fleece, native to Spain and N Africa, but now abundant in s Africa and Australia.

mesa Spanish, small tableland capped with resistant rock, denuded remnant offormer plateau.

meseta Extensive inland plateau forming about three-quarters of Spain.

mesosphere (I) layer of atmosphere between stratosphere and ionosphere; (il) obsolete name for mantle.

metamorphism Alteration in rock structure resulting from increase in heat or pressure or both combined.

meteor Body of matter travelling through space, being heated by friction with atmosphere, hence 'shooting stars'.

meteorite Body of stone and iron which has survived passage through atmosphere to land on earth.

meteorology atmosphere.

Scientific study of

Micronesia Groups of Pacific Islands, mainly volcanic, between Equator and 400 N and 130° and 1800 E.

midnight sun Phenomenon of polar lat. observed about mid-summer, when sun does not set in 24 hour period.

millet Species of grain grown in places

moraine M where soil is too poor for wheat and rainfall insufficient for rice, as in Africa and India.

millibar One-thousandth of a bar.

mirage Optical illusion caused by refraction of light, particularly in hot deserts.

misfit river One too small for present valley, either as result of river capture, change of climate, or glaciation.

mist Obscuring of ground layers of atmosphere by condensation of water particles, reducing visibility to bet­ween 0.6 and I.2m.(1 and 2 km.).

Mistral French, strong, cold, dry N wind blowing from Central France to Mediterranean, especially down lower Rhone Valley.

MohoroviCic Discontinuity Discon­tinuity between earth's crust and mantle, greatly affecting speed of earth­quake waves. Lies a{'prox. 20 m. (32 km.) deep under contments, but 4-6 m. (6-10 km.) under oceans.

Mollweide projection Equal-area pro­jection with central meridian as a straight line half scale-length of Equator.

monadnock Residual mountain rising above peneplain; named after Mount Monadnock, New Hampshire, U.S.A.

monsoon From Arabic word for season, referring particularly to reversal of pressure systems and winds over Arabian Sea and neighbouring land masses. Now applied generally over Asia, and also used to describe 'the rains' ofthe monsoon season.

montana Spanish, forested slopes OfE Andes in equatorial lat.

moon Sole natural satellite of earth, revolving round it in one sidereal month of approx. 271f4 days. Contri­butes to gravitational forces responsible for earth's tides.

moraine French, (I) masses of boulder-clay and stones carried and deposited by glacier; (il) arrangement of

649

M mortlake

this material to form particular land­form.

mortlake see ox-bow lake

mountain Landform of marked eleva­tion, bounded by steep slopes and rising to prominent ridges or peaks.

mud-flat Area of fine silt, usually covered and uncovered by tides, found in sheltered estuaries or behind bars and spits.

N

nappe French, over-thrust mass of rock in near-horizontal fold.

National Grid Rectangular system of lines printed on Ordnance Survey maps, providing method of precise reference to points on it by means of numbered co-ordinates.

national park Area set aside for pre­servation of scenery, vegetation, wild life and historic objects, for scientific purposes and for general public.

natural gas Free hydrocarbons in gaseous state, usually associated with crude mineral oils.

natural region Region defmed in terms of physical characteristics (relief, climate, vegetation, etc.).

nautical mile Unit of distance used in navigation, equal to 6,080 ft. (1,853 metres) or length of 1 minute of arc on Great Circle.

DaZe Promontory or headland.

neap tides Tides of low amplitude, about time of first and last quarters of moon.

650

Geographical Terms

mud-volcano Ejection of hot water and mud from volcanic vent, producing short-lived cone, as in Sicily, Iceland and New Zealand.

mulga Dense thicket of acacia-scrub on margins of central desert of Aust­ralia.

muskeg Water-logged land of N and NW Canada, with characteristic vegeta­tion cover of sphagnum moss.

nehrung German, spit enclosing or almost enclosing a haff.

Nevados Cold wind blowing down valley from Andes to high valleys of Ecuador.

neve French, accumulation area of firn.

Newlyn see Ordnance Datum

new town Town created and deve­loped as result of deliberate govern­ment planning to relieve over-crowding and population pressure in large cities (e.g. Crawley, Skelmersdale).

nife Mass of nickel-iron believed to comprise core of earth.

nimbo-stratus Low thick cloud, dark grey, from which continuous rain falls.

nimbus General term for clouds from which rain is falling.

nivation Rotting or disintegration of rocks beneath and round margins of patch of snow by chemical weathering and alternate freeze-thaw action.

nodal point (settlement) see node

Geographical Terms

node Settlement upon which sur­rounding settlements are dependent for goods, services, etc. or upon which lines of communication converge.

nomad Member of social group con­tinually changing habitation to find food for human and animal needs.

nomothetic Studying generalities rather than individual cases, so as to develop laws, principles, etc. opposite ideographic.

Norte (I) cold dry wind of Central America; (il) cold winter wind of E Spain.

North Atlantic Drift Movement of surface water of N Atlantic E from Grand Banks, Newfoundland.

North East Trades Trade winds ofN hemisphere.

o oasis Area in desert made fertile by presence of water sufficient for per­manent plant growth and human settle­ment.

occlusion Overtaking of one front by another in atmospheric depression. See cold front, warm front.

ocean Great body of sea-water sur­rounding land-masses and covering over 70% of earth's surface.

ocean currents Movements of surface water of the oceans, mainly clockwise in N hemisphere and anticlockwise in s. They are labelled warm or cool accord­ing to their temp. relative to the waters to which they flow.

Oceania Islands of Pacific and seas surrounding them.

Ordnance Datum 0 Norther Cold dry wind over N Ameri­can continent.

Nor'-Wester Fohn wind in s Island of New Zealand.

nucleated settlement Locational pat­tern of rural settlement where houses and farmsteads are clustered together in hamlets or villages; opposite dispersed settlement.

nuee anlente French, mass of hot gas, superheated steam and incandescent volcanic dust, producing glowing avalanche down flank of volcanic mountain.

nullah Indian, normally dry water­course becoming temporary stream after heavy rains.

nunatak Eskimo, prominent rock­peak projecting above surface of ice­sheet in Greenland and Antarctica.

oceanic islands Those of volcanic or coral formation unconnected with any continent.

oceanography Study of oceans, including nature of water, its move­ments, temp. and depth, as well as its flora and fauna.

odometer Wheel used by surveyors to record distance traversed.

ofI-shore bar Bar formed off coast of low-lying mainland.

onion-weathering . see exfoliation

opencast mining Form of excavation where mineral deposits lie near surface.

Ordnance Datum Mean sea-level calculated from hourly tidal observa­tions at Newlyn, Cornwall, from which

651

o ore

all heights on offIcial British maps are derived.

ore Mineral containing one or more metals in suffIcient quantity to warrant mining.

orogenesis Phase of mountain build­ing, when rock material is compressed, forming folds.

orography Description or depiction of relief.

orrery Working model of sun, moon, earth and planets to show relative movementsofthese bodies.

outcrop Portion of rock stratum pro­jecting above earth's surface.

outfield Land beyond infIeld, normal­ly extensive in use esp. in Saxon times:

p

Pacific coast see concordant coast

packet port One from which regular specifIed daily sailings occur, carrying cargo, mail and passengers.

pack-ice Masses of ice floating on sea to form almost continuous cover with little open water.

paddy Rice, either whole plant or grain in outer husk.

paddy field Flooded rice fIeld.

palaeomagnetism Study of past magnetism of rocks, thus of earth's magnetic fIeld, enabling geologists to gauge amount of movement of contin­ents in past.

pamir (i) poor grassland of high plateau in Central Asia; (il) proper

652

Geographical Terms

outlier (I) outcrop of rock whose surface is completely surrounded by older rocks; (iz) small isolated hill lying beyond main scarp and formed of same material.

outport Port near mouth of estuary, affording deeper water and closer prox­imity to open sea than previous river port.

outwash plain Alluvial plain formed by melt-water stream from glacier.

overspill Population from urban area moved to new settlement area because of overcrowding, slum clearance and population pressure.

ox-bow lake Surviving portion of former meander; also called cut-off or mortlake.

name of mountain complex in Central Asia.

pampa Extensive monotonous plain in Argentina-Uruguay; now used to describe temperate grasslands of s America.

Pampero Dry, cold s to sw wind over Argentina-Uruguay.

Papagayo Spanish, dry, cold NE wind affecting Mexican coasts.

'parallel roads' Series of wave-cut ter­races on valley sides thought to mark former glacial lake levels.

paramo Spanish, high, bleak plateau of Andes between puna and snowline.

parish (I) ecclesiastical unit in care of

Geographical Terms

single priest; (il) smallest local govt. sub-division in Britain.

pass Color gap through mountain range.

paternoster lakes Series of rockbasin lakes in former glacial valley.

peat Partially decomposed vegetation accumulated under waterlogged condi­tions and used as fuel or for horti­cultural purposes.

peda)fer Soil in humid climates where leaching has removed calcium com­pounds, leaving aluminium and iron.

pediment Large, gently sloping rock­platform at base of mountain slope in arid or semi-arid region.

pedocal Soil in dry climate where leaching has not removed calcium compounds.

pelagic Belonging to open sea, bet­ween littoral and abyssal regions.

peneplain LandscatJe evolved in last stage of cycle of erOSIOn, presenting an extensive, almost level plain.

peninsula Elongated projection of land into sea or lake.

perched block Boulder carried by glacier and left balanced on rock sur­race afterice has melted.

perigee Part of orbit of moon or planet which is closest to earth.

permafrost Permanently frozen soil, sub-soil or bed-rock.

petroleum Mixture of hydro-carbons found in earth in liquid, gaseous or solid form.

phosphates One of three main ele­ments needed by plants and used as fertilizer.

phylloxera Aphid, highly destructive of grape-vine.

physical planning Planning of land use (not to be confused with economic planning).

polders P piedmont glacier Mass of ice where several glaciers converge at base of mountain.

pike Mountain peak.

pitch (I) inclination of axis offold; (il) resinous substance formed in distilla­tion of coal tar.

plain Extensive area of relatively level country at low altitude.

planetary winds General atmospheric circulation producing series oflat. wind belts.

p~on Minute floating or drifting orgamsms of plant and animal life found in oceans, lakes and ponds.

plantation (I) estate in tropical regions, usually employing scientific methods and providing paid labour to produce cash crops for temperate regions; (il) areas of trees planted for commercial purposes.

plateau French, large, elevated, rela­tively level area ofland, often bounded by steep slopes.

playa Spanish, basin of inland drain­age in arid regions, containing shallow, fluctuating lake, often saline.

plucking Tearing action of glacier ice on rock surface.

plug Mass of acid lava occupying vent of dormant or extinct volcano, usually exposed by denudation.

plutonic rocks Igneous rocks cooled slowly deep in earth's crust, thus highly crystallized.

podsol Russian, leached soil of cool, humid climatic regions, where natural vegetation is coniferous or sandy heath.

polar front Line of discontinuity, marking meeting of polar and tropical air masses.

polders Dutch, land near or below sea level and reclaimed by draining and construction of dykes.

653

P poles

poles (I) geographic; Nand s extremi­ties of earth's axiS; (il) magnetic; poles of earth's magnetic fIeld.

Polynesia Islands of PacifIc, approx. lying between long. 120'w and 170'w.

Ponente Cool w wind on coast of Corsica and Mediterranean.

population lapse rate Rate at which population density decreases within Increased distance from city, town, etc.

population potential (I) Maximum population that can be maintained at a reasonable living standard in relation to resources available in given region. (il) Mathematical measure of total size of population found within given distance of a given location.

portage Carrying a boat, with its con­tents, overland where a natural inter­rupation to navigation occurs.

possibilism Philosophy that environ­ment offers a number of possible courses of development which man can take without serious consequences ensuing.

pot-hole Circular hole in rocks of river bed, caused by scouring action of water laden with pebbles; incorrectly used for swallow-hole in limestone districts.

prairie Extensive tract of temperate grassland in N America.

precipitation Deposition of atmos­phenc moisture on earth's surface, as dew, hail, sleet, snow.

pressure see atmosphere

654

Geographical Terms

prevailing wind One which, in any given area, blows most frequently from a specifiC direction.

primary industry Activities involved in collecting or winning natural resources. (e.g. mining, forestry, fIshing, agriculture).

Prime Meridian Generally accepted as Greenwich Meridian, from which all longitude is measured E and w.

prismatic compass Magnetic compass with prism, allowing observer to read bearing of distant object.

Probabilism Philosophy that there are several possible courses of action open to man within his environment of which some are more probable than others.

projection Geometrical method used by cartographers to represent the curved earth's surface on a plane.

promontory Headland or cliff or crag projecting into sea.

Puna s American, high, bleak plateau ofs America with cover of coarse grass, at altitude of 12,000-16,000 ft. (3,658-4,877 metres).

pumice Surface scum of volcanic lava, solidifIed to cellular rock.

Purga see Buran

puy French, small volcanic cone, frequent in Auvergne, France.

pyramid peak see hom

Q

qllll:llt. P!,!rsian, underground channel fOflmgatIOn water.

quagmire Bog which shakes under weight of man or beast.

R

radial drainage Pattem of streams flowing outwards down sides of uplifted dome or volcanic cone.

radiation Process by which body emits radiant energy.

radiation ~0If Layers of fog forming over low-lYIng areas during settled weather.

radiosonde French, self-recording instrument carried to high altitudes by balloon, for transmitting meteorologi­cal data back to earth.

rain Condensed atmospheric mois­ture falling in separate drops.

rain gauge Instrument consisting of funnel leading to collecting vessel, care­fully sited clear of obstructions and with rim of funnel I ft. (30 cm.) above ground.

rain shadow Area of comparatively low rainfall on lee side of mountain area.

raised beach Beach lifted by earth movements to form narrow coastal plam, often bounded by inland cliffs.

range (l) line of mountains or hills; (il)

quartz Crystalline silica or silicon oxide, essential element of granite.

quebracho Very hard wood found in Gran Chaco of Argentina or Paraguay.

open, unfenced area of grazing in High Plains of U.S.A.; (iii) difference bet­ween highest and lowest values oftemp. or pressures, at given place, over given period of time; (iv) limit of habitat of plant or animal.

rapid Area of broken, fast-flowing water in river, where slope of bed increases or where gently dipping band of hard rock crosses bed.

rattan Stem oflong, flexible climbing palm used in Indonesia for ropes, nets, baskets, mats, etc.

raw material Substance forming basis of manu. product.

reef (I) rock or coral formation of considerable extent, at or just above low-water mark; (iI) vein of metal or ore.

reg Arabic, extensive area of stony desert in Sahara, from which flOe sand has been blown.

regIme French, (I) seasonal fluctua­tion in volume of river or glacier; (il) seasonal pattern of climatic changes.

regionalism Feeling of regional iden-

655

R regolith

tity or consciousness held by the region's inhabitants.

regolith Greek, regas, blanket; lithos, stone; layer of disintegrated rock frag­ments below top-soil but above bed­rock.

rejuvenation Revival of erosive acti­vity, usually by river, resulting from fall in sea-level or local uplift ofland.

relative humidity Ratio of amount of water vapour present in air to amount needed for saturation at same temp.

relief Configuration of earth's surface.

remote sensing Gathering of in forma­tion by aerial survey (aerial photo­graphs, satellite recording, etc.).

resurgence Emergence of under-ground stream from cave.

rhyne or rhine Artificial drainage channel of Somerset Levels leading to larger channels or Drains.

ria Spanish, funnel-shaped indenta­tion of coast caused by submerging of estuary or lower part of river valley, generally where rock-structure is at right angles to coast.

rice Chief cereal crop of Monsoon and SE Asia, usually grown in flat, swampy fields.

Richter scale Used for measuring earthquake magnitude from instru­mental records, running from 0 to over 8·0.

Riding One of three former adminis­trative districts of Yorkshire.

656

Geographical Terms

rift valley Narrow trough between parallel faults or between series of step­faults.

rime Accumulation of ice-crystals extending to windward of exposed objects when frost, fog and wind occur simultaneously.

rip Turbulence in sea or river where tidal streams meet or enter shallows.

river Large body of fresh water flow­ing with perceptible current in defmite channel or course towards sea, lake, marsh,etc.

river capture Cutting-off of up{>Cr waters of one stream by neighbounng river system with greater erosional power.

Roaring Forties Uninterrupted stretch of ocean S oflat. 40·s where N to w winds blow with great strength and constancy.

roche moutonnee French, rock-mass projecting from floor of glacial valley, smooth and rounded on upstream side, but rough and angular on downstream side.

rubber Substance, derived from latex, obtained by tapping bark of tree found originally in Amazon basin.

run-otr Surface discharge of water from rainfall or snowmelt.

rural-urban fringe Transitional zone of edge of urban area where urban land uses (mainly housing, cemeteries and industrial estates) mix with mainly intensive rural land uses (e.g. market gardening).

s

saddle Broad, flat ridge between two summits.

saeter Norwegian, (I) farm on Norwe­gian alp, used only in summer; (il) upland pasture in Norway.

~brush Scrub vegetation in semi­and areas ofw OfN America.

salina Spanish, salt-encrusted surface of playa.

salinity Percentage of dissolved salts contained in sea water.

saltation Transport of solid material in series of hops (/) along bed of stream; (il) by wind action in deserts.

salt-flat Horizontal stretch of saIt­crust, formerly bed of salt-lake, tem­porarily orpermanentIy dried out.

salting Marsh rich in salt, often suit­able for grazing.

Samoan or Samum or Simoon Per­sian, warm, dry, descending wind in Persia; see FOhn.

sand Gritty particles, mainly of quartz, fmer than gravel but coarser than silt.

sand-dunes see dunes

Santa Ana Spanish, hot, dry, dusty wind from N or NE, descending from Sierra Nevada in California, doing much damage to orchards by desic­cation.

sanen Large sandstone block, found in S Britain, left after erosion of con­tinuous bed of which it formed part.

satellite town One associated with a larger town but separated from it by stretch of open land and dependent on it for goods and services (e.g. Slough, England, is a satellite town of London).

savannaorsavannahorsavana Tropi­cal grasslands, with scattered trees and bushes and tall grasses, resulting from marked precipitation regime.

scar Rock-face of cliff, common in carboniferous limestone OfN England.

scarp Steep face or slope of cuesta.

schist Fine-grained metamorphic rock.

scree Debris of rock, broken off by frost-shattering and forming steep slope at base of hill or mountain.

scrub Vegetation of stunted trees, bushes and brushwood on poor soils in semi-arid regions.

sea-breeze Diurnal movement of air, from sea to land, caused by differential heating.

sea-level (I) level which surface of sea would assume if uninfluenced by tides or waves or swell; (i/) mean level bet­ween high and low tide at any place.

seasons Divisions of year, determined by earth's position relative to sun.

secondary industry Activities pro­cessing the products of primary indus­tries to manufactured goods.

sedentary agriculture Cultivation practised by a settled farmer in one place; opposite shifting agriculture.

sedimentary rocks Those formed of materials deposited in layers by water or wind, made up of remains of pre­existing rocks, and of vegetation and animal deposits.

seif dunes Arabic, long dunes aligned across desert in direction of prevailing wind, forming steep-sided ridges extending many m.

657

S seismology

seismology Study and interpretation of earthquakes.

selvas Portuguese, rain-forest found in areas of heavy rainfall with high temp. all year.

serac French, pillars of ice in icefall where glacier reaches steep slope.

sericulture Culture of silk-worms.

serir Arabic, stony deserts of Egypt or Libya, covered by sheets of angular gravel.

shadoof or shadouf or shaduf Arabic, device for raising water from well.

Shamal Arabic, dry, dusty NW wind over plains ofIraq in summer.

sheet flood Hood resulting from violent rainfall! where water pours down slopes WIthout forming indivi­dual channels.

shield Large continental block remaining relatively stable since early geological times.

shieling Summer pasture, often with rough dwelling, in Scottish highlands.

shifting cultivation Primitive method used by nomadic peoples in tropics, whereby forest areas are cleared by burning, cultivated for a few years, then abandoned.

shire Large territorial division of Anglo-Saxon Britain, largely corres­ponding to county divisions introduced by Normans.

shoreline see coastline

shott Arabic, shallow, brackish salt­lake in N Africa.

sial Outer and lighter shell of earth's crust, composed largely of silica and alumina.

sidereal time Time measured by apparent diurnal movement of stars.

sierra Spanish, high range of mount­ains with serrated peaks, found mainly in Spain, N, Central and s America.

658

Geographical Terms

sila2e Layers of grass, clover or alfaffa, compressed in pit or silo, usually with addition of molasses and used as fodder.

sill (l) near-horizontal sheet of igneous rock, formed from magma intruded between bedding-planes; (i/) submarine ridge separating adjacent ocean basins; (iii) rock ridge at entrance to fIord.

silt Loose sedimentary material, coarser than clay and finer than sand, laid down in water.

sima Thick, heavier layers of earth's crust, below sial, composed largely of silica and magnesia and forming large part of ocean floors.

sink hole (I) solution hole or hollow or shaft in limestone or chalk country; (il) hollow down which surface water dis­appears.

Sirocco Italian, s to SE wind blowing from Sahara as hot, dry wind over N Africa coast, but reaching Malta, Sicily and S Italy as warm humid wind.

sisal Tropical plant with long fleshy leaves, whose fibres are used in making twine.

site Actual area occupied by town.

situation Location of town in relation to its surroundings.

skerry Low island, often forming series off-shore and parallel to coast, as in Scandinavia.

slag see basic slag

siump Mass-movement involving shearing of rocks, usually causing land­slips where massive rocks overlie clays or shales.

slurry How of wet mud.

smallholding Small unit of agric. land, intensively farmed by small­holder without paid labour, common in NW Europe.

smog Radiation fog over a town,

Geographical Terms

where sulphur dioxide is present and soot acts as nuclei for condensation.

snout Lower end of valley glacier, with melt-water stream issuing from cave.

snow Precipitation as ice-crystals.

snow-line Lower limit of permanent snow-cover.

soil Topmost layer of earth, compris­ing disin.ted rock, decayed organic matter, livmg organisms, water and air.

soil erosion Removal of soil by action of wind or water more rapidly than soil­forming processes can replace it; usually the result of over-cropping, over-grazing, dry farming or ploughing up and down steep slopes.

soke Former small administrative region in Britain (Soke of Peter­borough).

Solano Spanish, hot and oppressive SE wind bringil1$ occasional rain in summer to SE SpaIn.

solar system Group of celestial bodies revolving round sun, including planets, asteroids and satellites.

solar time Time reckoned by appar­ent motion of sun, recorded by sundial.

solfatara Italian, vent giving off sulphurous gases from volcano approaching extinction.

solitluction Downhill flow of surface deposits saturated with water, especial­ly ifthaw sets in at surface when ground beneath is still frozen.

solstice Time during summer or winter when sun is vertically above point marking its farthest distance N or S of equator, i.e. the two tropics.

solution Form of weathering where rock is dissolved by chemical action.

sound (I) passage between two land areas; (il) large inlet.

sounding Recorded depth of water.

stalactite S South East Trades Trade winds of S hemisphere.

Southerly Burster Strong, dry wind bringing unusually low temp. from polar regions to S Australia.

soya bean Seeds rich in protein, from pods of leguminous plant, once indi­genous to China, now common in U.S.A. and Europe.

spa (I) mineral spring; (il) town where mineral springs used for medicinal purposes.

spate Sudden flood, usually in mountainous areas, resulting from heavy rainfall or sudden snow-melt.

speleology Science of cave explora­tion and study of caves.

sphagnum regions.

Bog-moss of tundra

sphere ofintluence seecatcbment

spiUway Outflow channel draining lake dammed up by ice-sheet.

spinifex Australian desert grass with spiny sharp-pointed leaves.

spit Long, narrow tongue of sand or gravel projecting from land into sea or across estuary mouth.

spot-height Precise point where height above given datum is marked on map.

spring-line Line of springs where water-table intersects surface.

spring tides Those of considerable amplitude, about times of new and full moon.

stack Tall pillar of rock, detached from headland by wave action.

staithe Elevated stage from which wagons may discharge coal into ships.

stalactite Icicle-shaped mass of car­bonate of lime, deposited by percolat­ing water and hanging from roof of cave.

659

S stalagmite

stalagmite Stump-shaped mass of carbonate of lime, found on cave floor by deposition of water dripping from roof.

steppe Temperate grasslands of mid-lat. of Eurasia.

storm-beach Accumulation of coarse material well above high-water mark, produced by very powerful storm­waves.

storm-surge Rapid rise in level of sea above predicted tidal heights, caused by strong on-shore winds.

strait Narrow stretch of water linking two adjacent sea areas.

strandtlat Wave-cut platform otT coast OfN Norway.

stnta Layers or beds of sedimentary rock.

strath Broad, flat-floored valley in Scotland.

stratocumulus Continuous sheet of uniform dark grey cloud below 8,000 ft. (2,438 metres).

stratosphere Layer of atmosphere above troposphere, where temp. ceases to fall with increasing height.

T

tableland Broad, level-topped upland rising abruptly from lowland.

taiga Russian evergreen softwood forests of N continents where tree ~wth is slow, tree shapes give stability In wind and snow and needle leaves reduce transpiration.

talus see scree

660

Geographical Terms

stratus Thin, uniformly grey cloud sheet, found up to 8,000 ft. (2,438 metres).

striation Scratching and grooving of rocks by glacial action.

subsoil Partially decomposed rock between top-soil and bed-rock.

sucld Arabic, thick mass of floating vegetation on upper Nile.

Sumatra Squally wind in Malacca Straits, occurring suddenly, often at night, during sw monsoon.

Surazo Cold wind of s Brazil in anti­cyclonic conditions of winter.

surf Mass of breaking water when large wave approaches reef or steeply­shelving shore.

swallow-hole see sink hole

swash Mass of foaming water rushing up beach as wave breaks.

swell (I) regular undulating move­ment of waves in open ocean when they do not break; (il) gently sloping eleva­tion rising from sea-floor, but still well below ocean surface.

syncline Strata downfolded into form of trough by compressive forces.

tank Artificial pool or lake used in India or Sri Lanka to store irrigation water.

tarn Small pool or lake in mountain­ous areas, usually located in cirque.

tea Small evergreen shrub of tropical monsoon lands, whose leaves are picked and processed to form beverage.

Geographical Terms

tectonic Related to internal forces building up features of the earth's crust.

temperature Degree of heat or cold within atmosphere, measured on thermometric scale.

terminal moraine Crescent-shaped ridge of drift material and broken rock deposited by valley glacier at successive stages of retreat.

terrace (I) flat surface along valley side, marking former river level; (ii) embanked area along contour on steep sloping land, to prevent soil erosion.

terrace cultivation System where soil on steep slopes is retained by walls; often employs irrigation.

terra rossa Italian, reddish clay soils developed by chemical weathering in karst country under semi-arid condi­tions.

territorial waters Coastal waters over which bordering state retains jurisdic­tion; originally 3 m. (5 km.) WIde, now often extended, to claimed, up to 12,50 and even 200 m. (19,80,320 km.).

tertiary industry Activities providing services for primary and secondary industries (transport, finance, insur­ance, etc.).

thermal spring One with water temp. over 68°F. (20°C.) normally found III areas of active or recent vulcanism.

thermometer Instrument for measur­ingtemp.

threshold population Minimum size of population necessary to make a single establishment of any function economically viable.

thrust-fault Reverse fault at very low angle, where upper beds are pushed forward over lower ones.

tide Periodic vertical movement of sea-level in response to gravitational forces of sun or moon.

till see boulder clay

time zone Long. division within

truncated spur T which mean time of meridian near centre of zone is used as standard for whole zone.

tombolo Italian, sand or shingle bar linking island with mainland.

tor Isolated mass of rock, usually granite, weathered into prominent shapes; common in Devon or Corn­wall, England.

tornado (I) extremely violent whirl­wind, of short duration but very des­tructive, affecting Mississippi basin; (il) thundery squalls producing torrential rains over w Africa coasts.

trade winds Those blowing from sub­tropical high pressure cells to low pres­sure area of equatorial lat., noted for constancy offorce or direction.

Tramontana Italian or Spanish, cold, dry N wind blowing down from mountains in w Mediterranean basin.

transhuDruiDCe Seasonalmovementof animals and man to new pastures, usually at different altitude.

transpiration Loss of water-vapour by plants through leaves.

transport principle Theoretical arrangement of settlements, where transport costs are significant so that as many important places as possible lie on one route between larger towns.

transverse coast see discordant coast

tropic One of parallels oflat. (23'1t N and s of Equator) marking limits of area where sun may be directly overhead.

troposphere Lower layers of atmos­phere, where temp. fall with increasing altitude.

trough (I) elongated trench or ocean deep; (iI) glacial valley; (iii) depression between crests of two successive waves; (iv) narrow belt oflow pressure between two areas of high pressure.

trough-end Abrupt slope at head of glacial valley.

truncated spur Former interlocking

661

T tse-tse-fly

spur of river valley, now cut away by glacier, causing straightening of valley.

tse-tse Oy Small blood-sucking fly of Africa whose bite causes sleepmg­sickness in man and is often fatal to cattle.

tsunami Japanese, large-scale waves caused by submarine earthquakes, capable oftravelling vast distances very fast and causing considerable damage when surging ashore.

u

underground drainage Feature of areas of well-jointed rocks, as in carboniferous hmestone, where water flow may be directed below ground in distinct channels, from sink-hole to resurgence.

urban field Sphere of influence of town.

urban mesh Locational arrangement of central places.

urban renewal Planned renovation of buildings, services and facilities in an urban area.

urban sprawl Unplanned spread of

v valley Elongated depression between hills or mountains, usually containing river.

662

Geographical Terms

tumulus see barrow

tundra Lapp, zone of stunted vegeta­tion, often marshy, in N hemisphere, between polar snow and ice and N limits of tree growth.

twilight zone Area of town in decay because oflack of amenities, poor con­dition of buildings, etc.

typhoon Smal, intense tropical storm of China Sea and w Pacific margins.

building by outward expansion of town, often leading to development of conurbation.

urstromtiIer German, broad, shallow troughs eroded by melt-water from front of continental ice-sheet, notably in NW Europe, where they often contain parts of present post glacial river courses.

U-shaped valley Glaciated valley with flat floor, steep sides and straight course; may contain ribbon lake or mis-fit river.

uvala Depression in karst landscape, large than doline.

variation Magnetic angle by which magnetic compass needle deviates from true N for given point on earth's surface.

Geographical Terms

veld Afrikaans, open grassland of s Africa, ranging from high veld above 5,000 ft. (1,524 metres) through middle veld to bushveld in low country.

ventifact Pebble polished and faceted by wind-blown sand.

vicuiia Native animal of s America providing limited supplies of very flOe, soft wool.

viticulture Cultivation of the vine.

w

wadi Arabic, steep-sided rocky ravine in arid regions, usually dry except when heavy rains produce short-lived torrent

warm front Front of warm sector of depression, marking boundary where advancing warm air rises over cold air to produce broad belt of rain.

warm occlusion Where overtaking cold air is not as cold as air-mass in front.

washIand Embanked lowland border­ing river, where excess water is collect­ed in flood-time.

waterfall Steep fall of river water marking sudden change in gradient of river.

water-gap Narrow passage through ridge, cut by river.

water-power Originally referred to power generated by river turning mill­wheel, now synonymous with hydro­electric power.

watershed (I) line of separation bet­ween two adjacent drainage basins; (i/)

wheat W volcanic eruption Ejection of solid or liquid or gaseous material from interior of earth on to its surface.

volcano Hill or mountain, with vent through which lava, gas, steam and cinders are expelled.

V-sbaped valley Term for valley eroded by river.

vulcanicity All processes in which molten material is forced into earth's crust or onto the surface.

in U.S.A., term to describe catchment area of single river system.

waterspout Intense, rapid moving low pressure system over seas, producing pillar of water, common in tropics.

water table Upper surface of zone of saturation in permeable rocks. The level varies seasonally with the amount of precipitation and percolation.

wattle Type of Australian acacia.

wave-aJt bench Rock-shelf produced at base of cliffby wave action.

weather Condition of atmosphere at given place and time.

weathering Disintegration and decay of rocks in situ by climatic elements.

westerlies Prevailing winds of tem­perate lat., blowing from sub-tropical high pressure cells to low pressure zones in lat. 35-65".

wheat Widely cultivated cereal, most commonly grown extensively in tem­perate grasslands, but intensively in NW Europe.

663

W whirlwind

whirlwind Rapidly revolving stonn round centre of low pressure, product oflocal heating.

Williwaw Violent squall in Straits of Magellan.

Willy-willy Intense cyclonic stonn encountered offNW Australian coast.

wind air.

Horizontal current of moving

wind-gap Gap in ridge of hills, origin­ally caused by river erosion but now dry as result of river capture.

wind-rose Diagram of radiating lines, indicating by their length the propor-

x

xerophyte Type of plant adapted to arid conditions.

y

yarn Plant whose thick tubers fonn staple food of w Africa and s Sea Islands.

yardangs Wind-scoured ridges of rock resulting from erosion in desert

664

Geographical Terms

tion of winds blowing from each car­dinal point.

wine Product of fennented grape juice, though can be made from variety of other fruits.

winterbourne Intermittent stream in chalk areas, generally fiowinll only in winter when water table is highest. At other times it represents a dry valley.

wold Open hilly country in chalk or limestone regions of Britain, such as Cotswolds and Yorkshire Wolds.

wood pulp Major softwood ~roduct for making paper, artificial silk and cellulose paints.

lands where rocks of differing resistance run parallel to prevailing winds.

yazoo Deferred junction of trib. stream, resulting from migration of meanders in main river.

z zenith Point in heavens vertically above observer.

zeggen German, tabular mass of resis­tant rock, up to 100 ft. (30 metres) high, whose protective capping makes it stand out from softer rocks removed by differential erosion, mainly in arid areas.

zonda Warm, humid wind associated

with depression over Argentina or Uruguay.

zone of assimilation Area which is bein~ developed for business and retail actiV1ty on edge of present central business district.

zone of discard Area which is being vacated by business and retail activities on edge of central business district.

665