Key+words+and+definitions

The following list of keywords can be used throughout your study of this topic:


 * ﻿**Caldera**: a large basin-shaped crater surrounded by steep cliffs, formed by either a violent volcanic eruption that removed the top of the volcano or subsidence of the central part of one.
 * **Continent**: one of the seven great main landmasses on the Earth.
 * **Continental Drift**: the theory that describes how continents broke away and drifted from an original landmass.
 * **Convection Currents**: the deep, slow movements of molten rock from the upper mantle that moves tectonic plates.
 * **Dreaming**: stories that describe the Dreamtime, a time in which the Aborginial people believe the Earth came to have its present form and in whcih life and nature began.
 * **Erosion: **the wearing away of soil and rock by natural elements such as wind and water.
 * **Fault Mountains: **formed when layers of rock are fractured and one section moves down and another moves up.
 * **Fold Mountains: **formed when one plate slides down under another. Some rocks are forced down, others are forced upwards and bent into wave-like forms.
 * **Gross National Incomes (GNI) per capita: **total value of goods and services produced in a country in one year per person plus net income form abroad.
 * **Ice Age: **a time in which the Earth is colder, resulting in the expansion of glaciers and ice sheets and a fall in sea level.
 * **<span style="font-family: 'Comic Sans MS',cursive;">Indigenous people: **<span style="font-family: 'Comic Sans MS',cursive;">the descendants of the original inhabitants of an area.
 * **<span style="font-family: 'Comic Sans MS',cursive;">Latitude: **<span style="font-family: 'Comic Sans MS',cursive;">imaginary lines drawn around the Earth from east to west; they represent distance north or south of the Equator, measured in degrees, minutes and seconds.
 * **<span style="font-family: 'Comic Sans MS',cursive;">Longitude: **<span style="font-family: 'Comic Sans MS',cursive;">imaginary lines drawn around the Earth from north to south; they represent distance east or west of the Greenwich Meridian, measured in degrees, minutes and seconds.
 * **<span style="font-family: 'Comic Sans MS',cursive;">Mantle: **<span style="font-family: 'Comic Sans MS',cursive;">the layer of the Earth between the crust and the core.