Horizons World History Chapter 1

Front 1

theory

Back 1

possible explanation

Front 2

continental drift

Back 2

continuing movement of continents as Pangaea driftd apart

Front 3

fault

Back 3

a crack in the earth's crust along which movement occurs (earthquakes take place along these)

Front 4

magma

Back 4

molten rock formed by volcanic action

Front 5

lava

Back 5

magma that reaches the earth's surface

Front 6

weathering

Back 6

the wearing away of rock (water is the main cause; movement of glaciers can also cause it)

Front 7

glaciers

Back 7

thick masses of ice formed in areas where more snow falls than melts

Front 8

erosion

Back 8

carrying way of land by forces of nature

Front 9

deposition

Back 9

building up of sediment which creates new landforms

Front 10

delta

Back 10

triangle shaped piece of land formed by deposition at the mouth of a river

Front 11

trench

Back 11

deep ocean valley

Front 12

currents

Back 12

streams of ocean water

Front 13

tidal waves

Back 13

giant waves caused by earthquakes and severe storms

Front 14

water cycle

Back 14

sun's heat evaporates water, water forms clouds, clouds rain on land, water evaporates again

Front 15

tributaries

Back 15

smaller streams which flow together to form rivers

Front 16

river system

Back 16

river and all its tributaries

Front 17

drainage basin

Back 17

land area drained by a river

Front 18

rift

Back 18

huge crack in earth's surface

Front 19

reservoir

Back 19

lake formed behind a human made dam

Front 20

latitude

Back 20

distance north or south from the equator

Front 21

equator

Back 21

line on the globe which circles the earth halfway between the North and South Pole and divides the earth into Northern and Southern Hemispheres.

Front 22

longitude

Back 22

the distance east or west of the line that runs north and south through Greenwich, England. Lines of longitude are also called meridians.

Front 23

prime meridian

Back 23

the line of longitude that runs through Greenwich, England

Front 24

climate

Back 24

the kind of weather a place has over a long time

Front 25

temperate

Back 25

area in middle latitude--this climate varies with the seasons

Front 26

tropic

Back 26

area between the Tropics of Cancer and Capricorn

Front 27

altitude

Back 27

elevation

Front 28

rain shadow

Back 28

drier side of a mountain

Front 29

vegation

Back 29

plant life

Front 30

rain forest

Back 30

forest with thick vegeation and tall trees; rainfall may total 100 inches a year

Front 31

arid

Back 31

dry climate; rainfall totals 10 inches or less a year

Front 32

population distribution

Back 32

the way people are spread over the earth's surface

Front 33

environment

Back 33

surroundings; places in which people live

Front 34

irrigation

Back 34

use of connected ditches, canals, or pipes to carry water to land areas

Front 35

desertification

Back 35

change of fertile soil to desert land

Front 36

drought

Back 36

long period of dry weather

Front 37

migration

Back 37

movement of people

Front 38

urbanization

Back 38

movememt to cities by people

Front 39

metropolitan areas

Back 39

big cities and the suburbs that surround them