Th

e

P h y s i c a l Wor

l d

Th

e

P h y s i c a l Wor

l d

♦JA

CARANDA ATLA

S♦♦

JAC

ARANDA ATLAS

♦

8 9

ATLAS MTS

ETHIOPIANHIGHLANDS

BIEPLATEAU

Mt Blanc4807 m

THE ALPS

Mt Elbrus5642 m

Mt Kenya 5199 mKilimanjaro 5895 m

North Cape

Cape of Good Hope

Crozet Islands

Prince EdwardIslands

Svalbard

Faroe Islands

MadeiraIslands

Madagascar

Comoros

GreatBritain

Ireland

Mauritius

CanaryIslands

Tristan da Cunha

Ascension

Iceland

Cape VerdeIslands

Azores

Greenland

Shetland Islands

African Plate

Eurasian Plate

Antarctic Plate

Tropic of Cancer

Arctic Circle

Equator

Tropic of Capricorn

Lake OnegaLake Ladoga

Niger

R

Lake Volta

Lake Chad

River

Cong

o

Nile

R

Lake Malawi

Lake Victoria

Lake Tanganyika

NORTHSEA

NORWEGIANSEA

BARENTS SEA

RED

BLACK SEA

SEA

S O U T H A T L A N T I C

O C E A N

Santorini1950

VesuviusAD79

Etna1669 20 000

Stromboli1991

Lisbon1755 8.7 70 000

Messina1908 7.5 100 000

Avezzano1915 7.5 30 000

Erzincan1939 8.0 30 000

Turkey/USSR1988 7.0 25 000

North Iran1997 7.5 1560

Iranian

ArabianPlate

Over 4000 m

River

N a t u r a l e n v i r o n m e n t

Wetland

Island

Lake

2000 to 4000 m

1000 to 2000 m

500 to 1000 m

200 to 500 m

0 to 200 m

0 to 200 m

200 to 2000 m

2000 to 4000 m

4000 to 8000 m

Over 8000 m

K e y

Height ofthe land

Depth ofthe sea

Land belowsea level

Mountain

T e c t o n i c p l a t e s

Pacific Plate

Converging plate boundary

Diverging plate boundary

Uncertain plate boundary

Movement of plate

Volcano

Earthquake zone

Plate name

Mt Everest8848 m

Krakatoa 1883 36 500

Earthquake

Newcastle 1989 5.6 13

Eruption with date, deaths

Earthquake with date, magnitude, deaths

RO

CKY

MO

UN

TAINS

PLATEAU OFMATO GROSSO

MT

S

HIMALAYAS

DECCANPLATEAU

YABLONOVY RANGE

CENTRAL SIBERIANPLATEAU

UR

AL

MO

UN

TAIN

S

Mt Everest8848 m

Mt McKinley 6194 m

AN

DE

S

Llullaillaco 6723 m

Aconcagua 6960 m

Chimborazo 6267 m

Huascaran 6768 m

Mt Cook3764 m

K28611 m

DIV

IDIN

G

GR

EAT

RA

South West Cape

Cape Hatteras

Cape Cod

Greenland

NovayaZemlya

MaldivesSri Lanka

Sumatra

NorthernMarianas

Honshu

ShikokuKyushu

Borneo

Sulawesi New Guinea

Heard Island

NewZealand

Solomon Islands

Vanuatu

Java

WestHawaiian Islands

Marshall Islands

Kiribati

Queen Elizabeth Islands

Baffin Island

VictoriaIsland

BanksIsland

Falkland Islands

Easter Island

SocietyIslands

CookIslands

Fiji

Tonga

Samoa

Tuvalu

Tuamotu Archipelago

Aleutian Islands

KodiakIsland

Indies

Franz JosefLand

Newfoundland

South Georgia

Azores

Iceland

EllesmereIsland

Taiwan

SevernayaZemlya

New SiberianIslands

Philippines

Kerguelen Island

Chatham IslandsTasmania

Macquarie Island

Micronesia

Hokkaido

MarquesasIslands

GalapagosIslands

NewCaledonia

Pacific Plate

Juan de Fuca Plate

North American Plate

Caribbean Plate

South AmericanPlate

Scotia Plate

Nazca Plate

Antarctic Plate

Philippine Plate

Indo-AustralianPlate

CocosPlate

Mt Kosciuszko2228 m

Lake Balkhash

River

ObGanges R

Bayof

Bengal

Philippine Trench

Lake Eyre

Kerm

adec

Tren

chTo

nga

Tren

ch

Marian

a

Trench

Japan Trench

Kuril

Trench

Yenisey

Lena

R

Lake Baykal

River

Gulfof

Alaska

Great BearLake

Great SlaveLake

Lake Athabasca

Lake Winnipeg

Mississippi

R

Great Lakes

BaffinBay

HudsonBay

Davis Strait

Amazon R

Gulf ofMexico

KARA SEA

I N D I A N

O C E A N

JAVA SEA

TASMANSEA

CORAL SEA

BERINGSEA

LAPTEV SEA

EASTSIBERIAN SEA BEAUFORT SEA

CARIBBEAN SEA

N O R T H

A T L A N T I C

O C E A N

S O U T H

A T L A N T I C

O C E A N

A R C T I C O C E A N

P A C I F I C O C E A N

Mt St Helens 1980 61

Anchorage 1964 8.4

San Francisco 1906 8.3 452San Francisco 1989 7.1 62

Los Angeles 1994 6.6 57

Mexico City 1985 7.9 10 000

El Chichon 1982 1000

Paricutin 1943 2800

Nevado del Ruiz 1985 22 000

Chimbote 1970 7.7 67 000

Concepcion 1960 8.5 5000

Newcastle 1989 5.6 13

Tavurvur, Vulcan 1994 2

Lamington 1951 3000

Krakatoa 1883 36 500

Taal 1911 1335

Pinatubo 1991 700

Tangshan 1976 8.0 650 000

Kobe 1995 7.2 5000

Tokyo 1923 8.3 140 000

Mont Pelee1902 26 000

Soufriere Hills1996/97

Ruapehu1996

Quetta1935 7.5 45 000

N

Mt Fuji3776 m

Plate

0 1000 2000 3000

1 centimetre on the map measures1000 kilometres on the ground.

1 : 100 000 0004000 km

Modified Cylindrical Projection

Tambora 1815 56 000

Mantle

Trench

Inner core ofsolid metal

Outer core ofmolten metal

Crust

Convectioncurrent

Ridge

Continental plates

The Earth’s shell or crust is split into anumber of plates. These plates fit together

like a huge jigsaw puzzle. The plates floaton the semi-molten rocks of the Earth’smantle.

Heating from the Earth’s core causes thesemi-molten material in the mantle to

churn in currents. These currents carry thecrustal plates slowly along up to as much as

15 centimetres per year. This movement isknown as continental drift.

Sometimes the Earth’s plates collide, pushing up mountain ranges. The contactbetween these converging plates can also cause earthquakes and volcanoes. Platesbeneath the ocean move much more quickly than plates beneath the continents.

Mountain building

Most of the world’s great mountain regions are formed when crustal rocks arebuckled as the plates slide underneath each other. This folding process formed theHimalayas in Asia and the Rocky Mountains in North America. The process whererocks crack and sections move up or down is known as faulting and it forms bothmountains and rift valleys such as those in Africa.

Mountain building

Direction of plate movement

Continental plate e.g. Indian Plate

Convection current

Sediments folded and pushed upwards e.g. Himalayas

Continental plate e.g. Asian Plate

Convection current

Volcanoes

A volcano forms when magma, hotmolten rock from beneath the crust,emerges on the Earth’s surface through afissure or opening. When it does, thismolten rock is called lava.

A volcanic cone forms when there is anexplosive eruption of ash and cinders.These fall back to Earth, solidifying toform a steep volcanic cone like Mt Pari-cutin in Mexico.

A composite cone volcano, such as theone in the diagram on the right, is madeup of layers of ash and lava because theeruptions alternate between explosive(ash) and quiet (lava). Mt Fuji in Japanand Mt Etna in Italy are examples of acomposite cone.

Earthquakes

Earthquakes are caused by movements inthe Earth’s crust where the continentalplates converge. Earthquakes always havean epicentre, the point on the Earth’s sur-face from which the shock waves radiate.It is directly above the focus, the areaunderground where the stresses thatresult in the earthquake have built up.The shock waves decrease in intensity thefurther they are from the epicentre. After-shocks of lesser intensity may occur forweeks after the main earthquake.

The focus and epicentre of an earthquake

Strongest shock

Weakest shock

Epicentre

Focus

Volcanic eruption

Magma gathers in a magma chamber before it is forced to the surface.

Main volcanic ventAsh and gas explode from the crater.

Lava covers the ash and solidifies.

Ash settles in a layer over the volcano.

Pressure from gas and magma mixing underground forces magma up the main vent and branch pipes.

Branch pipe