ESSENTIAL VOCABULARY UNIT 2

ABYSSAL PLAIN
A huge underwater plain, usually more than 4,000 metres deep.

AEOLIAN EROSION

The process in which wind erodes and transports rocks and sand.

ALLUVIAL PLAIN

Aflat plain formed by the deposition of sediment from rivers.

ANTICLINE

A fold in the Earth’s surface where the rock layers bend upwards.

BASIN

A sunken landform which  is lower than the surrounding area.

BIOSPHERE

The thin layer of earth, wáter and atmosphere, where life is found.

CONE (relief)

A steep conical hill formed by the lava flow of volcanic eruptions.

CONTINENT

One of the Earth ‘s great land masses.

CONTINENTAL CRUST

The Earth’s crust beneath the continents.

CONTINENTAL DRIFT

The slow movement of tectonic plates on the Earth’s crust, which caused the continents to move apat over 
millions of years.

CONTINENTAL SHELF

A great underwater plateau that surrounds a continent, and is usually less than 200 metres deep.

CONTINENTAL SLOPE

The sloping terrain between a continental shelf and an abyssal plain.

CONTOUR LINE

A line on a map joining points of equal height.

CORE

The Earth’s centre, which is extremely hot, consisting of a solid inner core and a liquid outer core.

CRATER

A flat circular depression around a volcanic vent, formed by a volcanic eruption.

CRUST

The solid, outer part of the Earth’s surface.

DEPOSITION

Process in which eroded and transported rocks, sand and mud are eventually dropped in lower areas.

EARTHQUAKE

The shaking of the Earth’s crust along the boundaries of tectonic plates, when they slide against each other.

EPICENTRE

The point on the Earth’s surface where an earthquake is at its strongest, directly above the focus.

EROSION

The natural process by which the Earth’s rocks and soil are worn down and carried away.

FAULT

A crack in the Earth’ crust as a result of pressures from beneath the Earth’s surface.

FOCUS (or hypocentre)

The point below the Earth’s surface where seismic waves are released during an earthquake.

FOLD

A bend in rock layers as a result of pressures from beneath the Earth’s surface.

FOOTWALL

The block of land lying underneath a fault on the Earth’s surface.

FOSSIL

The remains of an ancient organism that was preserved and then became hard.

GEOLOGY

The scientific study of the materials that make up the solid part of the Earth.

HYPOCENTRE (or focus)

The point below the Earth’s surface where seismic waves are released during an earthquake.

ICE AGE

One of several periods in the Earth’s history when temperatures were very low, and much of the Earth’s 
surface was covered with ice.

INTERNAL FORCE

Pressure inside the Earth, that moves, pushes up or pushes down areas of land on the Earth’s surface.

LANDFORM

A physical feature of the terrain, like a mountain, valley or peninsula.

LAVA

The hot liquid rock that flows out of a volcano, before cooling and becoming solid.

LITHOSPHERE

The solid, rocky covering of the Earth’s surface.

MAGMA

The hot liquid rock that is found beneath the Earth’s surface.

MANTLE

The hot layer between the Earth’s crust and core.

MASSIF

A large mass of mountains.

MOUNTAIN

A natural elevation on the Earth’s surface that is higher than a hill.

MOUNTAIN RANGE

 Group or chain of mountains that are close together.

OCEAN

A huge mass of saltwater that separates two or more continents :71% of the Earth’s surface is covered by oceans.

OCEAN RIDGE

A raised area on the ocean floor that is an underwater mountain chain.

OCEANIC CRUST

The Earth’s crust beneath the oceans.

PANGEA

A single supercontinent that included all the Earh’s land masses around 200 million years ago.

PEAK

The highest point of a mountain.

PENINSULA

An  area of land that is mainly surrounded by water, but is connected to the continent.

PLAIN

A low flat area.

PLATEAU

A high flat area  that has been formed by the erosion of mountains.

RELIEF

The shape of the Earth’s surface.

RICHTER SCALE

A scale from 1 to 10 that expressed the force of an earthquake.

SEDIMENT

A natural material, like sand or clay, that is eroded and then transported by water or wind.

SEDIMENTARY ROCK

Rock that has formed by the deposition and solidification of sediment.

SEISMOGRAPH

An instrument for detecting and measuring earthquakes and seismic activity.

SHIELD

A large flat area of the Earth’s crust, composed of ancient rocks.

STRATA

Layers of sedimentary rock, which gradually accumulate at the Earth’s surface.

SYNCLINE

A fold in the Earth’s surface , where the rock layers bend downwards.

TECTONIC PLATE

One of the huge plates that make up the Earth’s crust, and slowly slide towards or away from each other.

TOPOGRAPHIC PROFILE

A representation of the different altitudes along a line drawn on a topographic map.

TRANSPORTATION

The movement of eroded material by the sea, rivers, ice or the wind.

TREMOR

A very small earthquake, often imperceptible to human beings.

TRENCH

A deep crack on the ocean floor.

TSUNAMI

A huge tidal wave caused by an earthquake on the ocean floor.

U-SHAPED VALLEY

A valley formed by glacial erosion, shaped like the letter “u”.

VENT

The main channel of a volcano.

VOLCANIC ERUPTION

The sudden expulsion of hot rocks, ash and gases from a volcano.

VOLCANO

A crack in the Earth’s crust through which magma and gases are ejected.

V- SHAPED VALLEY

A valley formed by the flow of a river, shaped like the letter “v”.