Geography Paper One: Internal and External Processes

Comprehensive practice flashcards covering internal land forming processes, mapwork, photograph interpretation, climate, vegetation, and forestry based on the Geography Paper One lecture notes.

Earth movements

The displacement or movement of crustal rock caused by tectonic forces which originate and operate in the interior of the earth.

Horizontal earth movements

Also known as orogenic or lateral movements, these act along a tangent and cause crustal rocks to stretch, shorten, or shear.

Vertical earth movements

Also known as epeirogenic movements, these occur along the Earth's radius leading to up-warping, down-warping, or tilting.

Isostasy

The state of balance existing between the lighter upper crust (SIAL) and the denser inner region (SIMA) of the earth.

Pangea

The initial single land mass that existed before breaking into Laurasia and Gondwanaland, according to the Continental Drift Theory.

Panthalassa

The great ocean that surrounded the single land mass Pangea, whose floor was mainly the sima layer.

Tethys

A narrow ocean that separated the blocks of Laurasia and Gondwanaland during the late Precambrian period.

Plate Tectonic Theory

A theory stating the earth's crust is made of rigid blocks called tectonic plates sitting on a semi-molten layer of the upper mantle.

Folding

The bending of the rocks of the earth’s crust due to earth movements, occurring primarily in sedimentary rocks in a semi-elastic state.

Anticline

The upfolds created during the process of folding where rock layers are bent upwards.

Syncline

The downfolds created during the process of folding where rock layers are bent downwards.

Geosyncline

An extensive depression formed on the surface of the earth that fills with water and accumulates layers of sediment.

Orogenesis

The technical term for the processes involved in fold mountain building.

Faulting

The cracking or fracturing of rocks of the Earth's crust due to tectonic forces such as tension, compression, or shear.

Fault scarp

A steep slope formed by the vertical movement of the earth along a fault, representing the face of the fault plane.

Block Mountain

Also known as a Horst, it is an elongated upland bordered by fault scarps on both sides.

Rift Valley

A long narrow trough between more or less parallel faults with steep fault scarps on either side.

Vulcanicity

The process through which gaseous, liquid, or solid molten materials are intruded into the earth's crust or extruded onto the surface.

Magma

Molten rock existing in a semi-solid state deep below the earth's crust.

Lava

Molten rock that has been ejected onto the earth's surface and has lost its gases.

Caldera

A large basin-type hollow bounded by steep cliffs, formed by a volcanic explosion or the collapse of a volcanic cone.

Geyser

A type of hot spring in which water is violently expelled from the surface into the air as a column of boiling water and steam.

Batholith

A large-scale intrusion of magma so deeply seated that the root is of unknown depth, usually made of granite.

Dyke

A mass of intrusive rock that cuts across the bedding plane of existing rock; it can be vertical or inclined.

Sill

A horizontal intrusion of magma between the strata of the bedding plane.

Earthquake

The sudden earth movement causing trembling vibrations within and below the earth's crust.

Seismograph

An instrument used for measuring the intensity and magnitude of earthquakes.

Mercalli Scale

A scale expressed in Roman numerals from I to XII used to measure the intensity of an earthquake.

Richter scale

A scale ranging from $0$ to $8.9$ used to measure the magnitude (energy) produced by an earthquake.

Bearing

A measurement of direction read from the North in a clockwise direction through a full circle of $360^\circ$.

Latitude

Imaginary lines drawn on the globe or map used to show how far north or south a place is from the equator.

Longitude

Imaginary lines drawn showing how far east or west a place is from the Prime Meridian ($0^\circ$).

Vertical Interval ($VI$)

The fixed and constant height difference between two successive contour lines on a map.

Hachures

Short lines drawn down-slope in the direction of the steepness gradient to represent relief on mountains or hilly areas.

Dead ground

An area hidden from the eye of the camera by an object in a ground photograph.

Climate

The average weather conditions of a place observed and recorded over a long period of time, usually $30$ to $35$ years.

Micro-climate

A climate experienced within a small or localized area that is different from the general climate of the region.

Aridity

A state of land being deficient in moisture leading to scanty vegetation and deficiency in soil fertility.

Global warming

An increase in Carbon IV Oxide levels in the atmosphere leading to an increase in the earth's surface temperatures.

Plant community

An assemblage of plants that grow together in a particular physical habitat or site.

Natural vegetation

Plant cover that grows and spreads through natural means of seed dispersal without human interference.

Photoperiodism

The response of plants to the duration of daylight, affecting flowering, seeding, and leaf fall.

Xerophytic plants

Plants highly tolerant to drought and adapted to survive in dry areas with limited moisture.

Forestry

The science of planting, caring for, and managing trees, forests, and their associated resources.

Afforestation

The planting of trees in order to establish a forest where none existed before.

Agro-forestry

A land-use system involving the mixture of tree planting, crop growing, and livestock rearing on the same piece of land simultaneously.