Chapter 1 The Australian Continent, glossary:
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 the cone
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 movement of molten rock from the upper
mantle that moves tectonic plates
Dreaming: stories that describe the Dreamtime, a time in which the Aboriginal
peoples believe the Earth came to have its present form and in which 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 income (GNI) per capita: total value of goods and services produced
in a country in one year per person plus net income from 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
Indigenous people: the descendants of the original inhabitants of an area
Latitude: 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
Longitude: 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.
Mantle: the layer of the Earth between the crust and the core
Megacities: cities with more than ten million people minute: each degree of latitude
or longitude can be divided into 60 smaller segments called minutes, often
represented by the sign (e.g. 20°30′ is
20 degrees and 30 minutes)
Prime Meridian: the most important line of longitude. It runs through the Greenwich
Observatory in England. All other lines of longitude are either east or west of it.
Sacred sites: places where important events in the Dreaming took place
Sediment: material deposited by a stream or other body of water
Tectonic plates: the various slow-moving plates that make up the Earth’s crust.
Volcanoes and earthquakes often occur at the edges of plates.
Tectonic processes: activities below the Earth’s surface that cause the breaking and
bending of the Earth’s crust
Time zones: the 24 zones of different time into which the Earth is divided
Topography: physical features of an area of land — its height and shape
Weathering: the breakdown of bare rock by water and temperature changes
Chapter 2 Physical characteristics that make Australia unique,
glossary:
Climate: the long-term variation in the atmosphere, mainly relating to temperature
and precipitation
Deposition: the laying down of material carried by rivers, wind, ice, ocean currents or
waves
Drainage basin: the area of land that feeds a river with water or the whole area of
land drained by a river and its tributaries
Drought: a period of below average precipitation
Ecosystem: a system formed by the interactions of the living organisms (plants,
animals and humans) and physical elements of environments
Endemic: native to a particular area and found nowhere else
Erosion: the wearing away of soil and rock by natural elements such as wind and
water
Isobars: lines drawn on a map joining places of equal barometric pressure
Marsupial: a mammal that keeps and feeds its young in a pouch for a few months
after birth
Mass movement: the movement of rock and soil down a slope due to gravity
Monotreme: mammal that lays eggs; the only species are the platypus and echidna
Monsoon: the seasonal change in wind direction that is experienced in much of the
tropics
Regolith: the layer of broken rock and soil on top of the solid rock of the Earth’s
crust; also known as mantle rock
Renewable resources: resources that can be replaced in a relatively short amount of
time (for example, trees)
Salinity: the presence of salt on the land surface, in soils or rocks, or dissolved in
water in our rivers or ground water
Species: a group of plants or animals of the same kind, able to breed with each
other
Synoptic chart: weather map that uses isobars and other symbols to show the
movement of weather systems and patterns of temperature and rainfall tectonic:
refers to the forces or conditions within the earth that cause movements of the crust
such as earthquakes, folds, faults and volcanoes
Topography: physical features of an area of land — its height and shape
Unique: unlike anything else; the only one of its type
Weathering: the breakdown of bare rock by water and temperature changes
World Heritage List: areas designated as being of global importance for
conservation and study
Chapter 3 natural hazards in Australia, glossary:
Alluvium: the loose material brought down by a river and deposited in its bed, flood
plain or delta
Bushfire: fire burning out of control in the open; also called a wildfire
Cold front: boundary between warm air and advancing cold air
Drought: a period of below average precipitation
Earthquake: series of shock waves that are generated by a disturbance in the Earth’s
crust
El Niño event: the reversal (every few years) of the more usual direction of winds
and surface currents across the Pacific Ocean. This change causes drought in
Australia and heavy rain in South America. (Normally Australia has the rain and
South America has the dry conditions.)
Epicenter: the point on the Earth’s surface directly above the focus of an earthquake
Fire front: the edge of the fire that spreads at the fastest rate
Firebrand: aerial burning fuel that blows ahead of the fire front
Firestorm: an intense fire, which may generate strong convection currents and
violent winds that cause long- range spotting and flame spirals
Flash flooding: sudden and destructive rush of water usually downhill following
heavy rains on higher land
Flood: an unusual accumulation of water that overflows from rivers, lakes or the
ocean onto land that is not normally covered by water
Flood mitigation: measures aimed at preparing for floods and trying to reduce their
effects, such as constructing artificial levees, strengthening bridges, raising road
levels and enlarging drains
Flood plain: part of a river valley covered by water during floods
Fuel: any material that burns
Heat wave: a short period (usually a few days) of well above average temperatures
La Niña event: a period of well above average rainfall in eastern Australia, which
often brings floods
Natural disaster: occurs as a result of a hazardous natural event that dramatically
affects a community
Natural hazard: a natural event or object that is a potential source of harm to a
community
Richter scale: used to measure the energy of earthquakes
Sclerophyll: plants found in low rainfall areas; their leathery leaves help reduce water
loss
Southern Oscillation: a major air pressure shift between the Asian and east Pacific
regions. Its most commonly known extremes are those referred to as El Niño events.
Stubble: the stumps or stalks left in the ground when a crop, such as wheat, is
harvested
Subsidy: direct financial aid given by a government to an individual or group to
reduce the price of a good or service
Tropical cyclone: severe weather event that occurs when warm, moist rising air
begins to spiral upwards. Very strong winds, heavy rain and rough seas often
accompany tropical cyclones.