1、Guide toSAVAGEEARTHA dramatic journey across the planetTrevor DayGuide toSAVAGE EARTHTrevor DayA Dorling Kindersley BookCONTENTS4THE BIG BANG6VIOLENT PAST8MOVING CONTINENTS10VOLCANOES12ERUPTION!14RIVERS OF FIRE16MAKING MOUNTAINS18EARTHQUAKES20SHOCK WAVES22TSUNAMI24SPREADING SEASLONDON, NEW YORK, MUN

2、ICH, PARIS, MELBOURNE, DELHIProject Editor David John Project Art Editor Elaine Hewson Editor Lucy HurstSenior Editor Fran Jones Senior Art Editor Marcus James Category Publisher Jayne ParsonsManaging Art Editor Jacquie Gulliver US Editors Gary Werner, Margaret Parrish DTP Designer Nomazwe Madonko P

3、icture Research Brenda ClynchJacket Design Hedi Gutt Jacket Editor MarizaOKeeffe Production Erica RosenFirst American Edition, 2001 First Paperback Edition, 200601 02 03 04 05 10 9 8 7 6 5 4 3 2 1Published in the United States by DK Publishing, Inc.375 Hudson Street New York, New York 10016Copyright

4、 2001 Dorling Kindersley Limited First paperback edition 2006A Penguin CompanyAll rights reserved under International and Pan-American Copyright Conventions. No part of this publication may be reproduced, stored in a retrieval system, or transmittedin any form or by any means, electronic, mechanical

5、, photocopying, recording, or otherwise, without the prior written permission of the copyright owner. Published in Great Briatin by Dorling Kindersley Limited.CIP data is available from the Library of Congress Paperback ISBN 0-7566-1791-X Hardback ISBN 0-7894-7919-2Color reproduction by GRB Editrice

6、, S.r.l.,Verona Printed and bound in China by Toppan Printing Co., LtdSee our complete catalog 26SUBMARINE LANDSCAPES28WEATHERING AND EROSION30CAVES AND CAVERNS32ICY EXTREMES34GLACIERS36AVALANCHE!38DESERTS40DROUGHT42FOREST FIRES44CLIMATE CHANGE46EXTREME WEATHER48FLOODS50DROWNING WORLD52C

7、RUEL SEA54BURIED TREASURE56GLOBAL ECOSYSTEMS58ASTEROID STRIKE!60SAVAGE FUTURE62EARTH DATA64INDEX AND CREDITSDK GUIDE TO S AVAGE EARTHTHE BIG BANGTinto space. The savage forces that batter, shake, and shape theO UNDERSTAND HOW OUR PLANET WAS CREATED , we have to lookEarths surface today were set in m

8、otion billions of years ago and are still going strong. Beneath the surface, immense heat causes molten rock to circulate, moving giant sections of the crust, triggering earthquakes, and shooting out molten rock from volcanoes. The enormously high pressures and temperatures deep inside the Earth con

9、tinue to generate heat through radioactive decay and chemical changes. The Sun, however, has much more power, and without its light and warmth, life here would not exist. But the Earths story really begins with the biggest explosion the universe has ever known the one that created it.SOMETHINGFROM N

10、OTHINGMost scientists now agree that everything we know started with the Big Bang time, space, and all the matterin the universe. About 13 billion years ago, the universe burst into existence with anunimaginably large explosion. The fireball was so concentrated that matter was created spontaneously

11、out of energy. At the instant of creation, the universe was infinitely hot and dense. Then it expanded and cooled, and created the galaxies, and the stars andplanets they contain. About 4.6 billion years ago, our own solar system came intobeing.UNIQUE EARTHAmong the planets in the solar system, Eart

12、h is unique. Seen from space, its swirling clouds and blueoceans show that it has plenty of liquid water. The Earths gravity is strong enough to trap a protective atmosphere. It is also the right distance from the Sun to have habitable climates. Water and anatmosphere are two conditions vital for th

13、e evolution of life as we know it.4THE BIG BANGSTAR MAKERInside its whirling clouds of cosmic dust, the spectacular Orion nebula gives birth to stars. Our Sun was created in the same way by the dust of the vast solar nebula, several billion years ago. When the solar nebula grew old, material was dra

14、wn into its center, which became denser and hotter as it generated energy by nuclear fusion. In a gigantic nuclear explosion, the infant Sun was born, and began radiating the first sunshine in our solar system.PlutoUranusNeptuneSaturnMarsEarthVenusJupiter MoonMercurySunSOLAR SYSTEMWhen our solar sys

15、tem was forming, the early Sun probably lay at the center of a disc-shaped cloud. Inside the cloud were liquids and gases, swirling around with dust and ice. Under the pull of gravity, dust particles clumped together to form rocks. Metal-rich rocks near the Sun came together to form the inner planet

16、s. In the cooler, outer regions, ice combined with rock and lighter gases to form the outer planets.LIFE ELSEWHERE?The conditions that allow complex lifeforms to flourish on Earth mightberare elsewhere in the universe. Simplemicrobes, however, can survive in themost hostile places, and may exist ono

17、ther planets or their moons. In 1996, aMartian meteorite found in Antarcticacontained what at first appeared to befossilized bacteria (right). Somescientists believe Mars may once havesustained simple, microbial life.5DK GUIDE TO S AVAGE EARTHVIOLENT PASTTHE EARLY EARTH WAS A RED -HOT, MOLTEN HELL .

18、 Space debrisfrom the collapsed solar nebula was flying in all directions,causing meteorites and comets to smash into the young planets surface. These violent bombardments raised the Earths temperature higher and higher. Then, not long after it was formed some 4.6 billionyears ago, the Earth was str

19、uck by an object the size of Mars. The impact released a heat so intense that it melted the planet. Debris from the impact explosion splashed out into space and gathered together to form the Moon. But the Earth did not remain searingly hot. It gradually cooled into a planet with a solid surface, oce

20、ans, continents, and an atmosphere. In fact, for more than three-quarters of its existence the Earth has sustained living organisms. Now approaching middle-age, the Earth has about five billion years left to bask in the life-giving heat of the Sun.AtmosphereCrustMantleEARTHS TRANSFORMATIONMore than

21、four billion years ago, the Earths molten rock began to separate into layers. Heavy, iron-rich material sank to the intensely hot core.Silicon-rich material gathered at the surface to form a crust. Molten rock becamesandwiched between the core and crust to form the mantle. On the surface,granitelike

22、 rocks thickened the crust and formed the first continents.Outer coreMolten outer coreBLASTS OF THE PASTThis is an artists impression of the young Earths violentlandscape. Space debris and lava flows must have ravaged the brittle crust. Asmeteorites landed, they punched holes in the surface and plun

23、ged into the hot interior, sending uphuge showers of molten rock. Gradually, the thin surface crust grew thicker. From time to time, slabs of cooled crust plunged back into the molten mantle below and were melted again.Solid inner coreDINO KILLERFor more than 100 million years, the Earth was ruled b

24、y dinosaurs. They became extinct quite suddenly about 65 million years ago. Their disappearance was probably causedby a massive meteorite or comet that collided with the Earth. The impact would have shrouded the world in a cloud of dust that blotted out the Sun for many months. In the freezing darkn

25、ess, most of the worlds plant and animal life died, including the dinosaurs. Some small, hibernating racoon-like mammals survived.VIOLENT PASTOCEANSThe water that filled the first oceans may have come from comets that collided with the Earth. A comet (left) is a giantsnowball of ice and rock. Water

26、also came from the steam given off by molten rock (magma) flowing ontothe surface. The steam condensed in the atmosphere, formed clouds, and fell to Earth as rain, just as the steam from volcanoes does today.THE SUNOur Sun is an average-sized star similar to billions of others in the galaxy. Without

27、 its heat, Earth would be uninhabitable.Scientists calculate that the Sun has about five billion years of life leftbefore it uses up its fuel supply of hydrogen. When it does, it will expand 100 times in size into a massive sphere called a red giant,and will destroy the Earth.ATMOSPHEREThe Earths ea

28、rly atmosphere was rich in volcanic gases such as carbon dioxide. Todays atmosphere has little carbon dioxide, but contains oxygen. The change was caused by early life-forms tiny organisms that released oxygen as waste.These clumps (left) are made by microbes called cyanobacteria, which trap sunligh

29、t to make food. They are very similar tothe early oxygen-making organisms.ICE AGESDespite its fiery origins, much of the Earth has been covered in ice during its history. Ice spread from the poles toward the Equator when the climate cooled, and retreated as it warmed.This may have been caused by a s

30、low wobble of the Earths axis, which alters its distance from the Sun. Present-day glaciers (left) show us how the world must have looked during the ice ages.7DK GUIDE TO S AVAGE EARTHMOVING CONTINENTSTthe continents that make up most of the Earths land surface are alwaysHE GROUND BENEATH OUR FEET I

31、S NOT AS STEADY as we may think. In fact,on the move, shifted around by forces deep inside the Earth. This movement is known as continental drift. It takes place because the inside of the planet is hot and turbulent. The intense heat generated at the Earths core is carried upward where it disturbs t

32、he cool, rocky surface. This forces the platesof crust that make up the continents, called tectonic plates, to move. Each year the continents drift by nearly half an inch (about a centimeter). Some are crunching together, some are splitting apart, others are grinding past each other. As this happens

33、 the Earths features are created or changed. Violent earthquakes and volcanoes are dramatic reminders that the plates never stop moving.TECTONIC PLATESEach tectonic plate hasa lower layer of solid rock and an upper layer called the crust. The platesride upon Earths slowly moving, mostly solid mantle

34、. Where the crustis thin, the Earths surface is low-lying and covered by seas and oceans. Continents form where the crust is thicker and stands higher. As the tectonic plates move, the continents are carried with them and the oceans change shape.N ORTHA M E R I C A NPLATEEURASIAN PLATEJUANDE FUCA PL

35、ATEIRANIANPLATEARABIANPLATEPHILIPPINE PLATECARIBBEANPLATEPACIFICPLATECOCOSPLATEA FRICANPLATES OUTHA M E R I C A NPLATEI NDO -A USTRALIAN PLATENAZCAPLATEKEY TO MAPSubduction zoneSCOTIA PLATEMovementMid-ocean ridge and faultsof plate Collision zone or transform faultANTARCTIC PLATEUncertain plate boun

36、daryVolcanoGLOBAL JIGSAW PUZZLEThe plates that form the Earths surface fit together like a jigsaw puzzle. This map shows the boundaries of the Earths plates and the directions in which the plates are drifting. The pieces slowly change shape as they move. Great mountain ranges have formed along the b

37、lue zones where plates are colliding. Lines of volcanoes are dotted along the red zones where one plate is sinking (subducting) below another, causing molten rock to erupt to the surface.THE EVIDENCEWhen the German scientist Alfred Wegener stated in 1915 that todays continents were once part of a si

38、ngle landmass, people ridiculed him. But Wegener was right. He argued that although ancient plant fossils, such as the Glossopteris fern (right) are found on widely separated continents, they could only have come from one original continent. Today, geologists agree with Wegenerthat the continents di

39、d indeed drift apart.8MOVING CONTINENTSWHEN PLATES COLLIDEThe Andes Mountains of South America extend along the Pacific coast for about 5,530 miles (8,900 km). They began to form about 170 million years ago when the Nazca Plate collided with (and sank beneath) the South American plate. The foothills

40、 (above) show where a folding, or buckling, of the continental crust has occurred. Mountain-building in the Andes slowed down about six million years ago.Ocean trench forms where oneContinentalplate sinks belowSpreading boundary, where two plates move apart.Transform fault, where two plates slide pa

41、st each other.crustanother.Convergent boundary, where collided continental crust has uplifted mountains.WEST OF JAVAThis is Anak Krakatoa in Indonesia, a volcano that first erupted in 1927. It is one of a long string of volcanoes that lies along a boundary where the Indo-Australian plate is sliding

42、below the Eurasian plate.The subsiding plate melts as it isforced downward into the Earths mantle, and squeezes magma to thesurface to formvolcanoes.Subsiding plateVolcano fed from subsiding plate.Magma rising from the mantle.PLATE BOUNDARIESThe illustration above shows what happens at the boundarie

43、s that separate one plate from another. At spreading boundaries, plates are moving apart, and molten rock (magma) rises up to fill the gaps. Transform faults lie along boundaries where plates scrape past one another, generating earthquakes. Where convergentboundaries are found, plates are pushing to

44、gether to create mountain ranges in a process of folding and uplifting.SPREADING RIDGESThe Mid-Atlantic Ridge is a spreading plate boundary that stretches from the Arctic to the Southern Ocean. Most of it lies beneath the ocean, but at Thingvellir in Iceland (left), it crosses over land. The boundar

45、y between the North American plate on the left and the Eurasian plate on the right is clearly visible.Where the plates have moved apart, the crustin between has collapsed, forming a steep-sided rift valley. The region is very active volcanically. In 1963, a huge underwater eruption occurred 80 miles

46、 (130 km) south of Thingvellir. Lava rose to fill the gap in the widening ridge, and cooled to form the new island of Surtsey.9DK GUIDE TO S AVAGE EARTHVOLCANOESTdarkens. A volcano is erupting, firing red-hot boulders into the airHERE IS A THUNDEROUS EXPLOSION , the ground trembles, and the skyand b

47、elching out clouds of ash and poisonous fumes. Volcanoes are vents or fissures in the Earths crust that allow molten rock to rise up from the hot interior and spill onto the surface. An active volcano may erupt continuously, and over time may become a broad mountain with gentle slopes. Other volcano

48、es may lie dormant (sleeping) for most of the time. They erupt only at rare intervals but with explosions violent enough to destroy their own cones and a wide surrounding area. Many of the Earths mountains were formerly volcanoes,but are now extinct. Today, there are more than 1,000 active volcanoes

49、 on land, and many more under the sea.INSIDE AN EXPLODING VOLCANOWithin and beneath Earths crust, rock can become so hot that it melts. Thiss molten rock, called magma. can rise through a gap in the crust and become trapped in a magma chamber a cavity beneath the volcano. As more magma enters, press

50、ure builds up until the volcanos clogged vent is blasted open.The feeder pipe to the vent then acts like a gun barrel that shoots out lava, rocks, ash, and steam.Cone is built up by successive layers of lava and ash over thousands of years.Magma collects in the magma chamber and builds up pressure i

51、n the clogged vent.ALL SHAPES AND SIZESA volcanos shape depends on the thickness of its lava and the frequency and size of itseruptions. Dome volcanoes build up cones from the layers of lava and ash they produce. Fissure volcanoes are fairly flat, and trickle lava from big cracks in the ground. Cald

52、era volcanoes, like this one (left) at Crater Lake, Oregon, lie inside vast craters made by a previous, massive explosion that collapsed the original mountain.HOT SPOTMost volcanoes occur where the Earths plates collide or move apart. But some, like the Hawaiian islands, arose in the middle of a pla

53、te because they were created by a “hot spot” in the Earths mantle, which burned through the crust and formed a volcano. The volcano stops erupting as the moving plate carries it away from the hot spot, and a new volcano forms.The chain of islands grows as the plate moves.Hawaii is formed from the wo

54、rlds tallest volcanic cone. It is a recent island that emerged from the sea within the last million years.Oahu was created between two and three million years ago by the same hot spot that gave birth to Hawaii.10VOLCANOESSLEEPING BEAUTYThe graceful slopes of Mount Fuji in Japan rise more than 12,000

55、 ft (3,500 m) above the surrounding plain. Itsperfect cone built up from layers of lava and ash, is a favorite symbol in Japan. Some believe thatgods live in the summit, which is always covered in snow. It last erupted in 1707and has been dormant ever since.VOLCANO BREATHScientists in Iceland wear g

56、as masks to monitor the poisonous gases escaping from a fumarole a small volcanic vent. These sites are sampled regularly. An increase of gases, or a change in their mixture, can give an early warning of an eruption.VOLCANIC WONDERLANDOver thousands of years, underground water heated by volcanic act

57、ivity has trickled down the side of this famous plateau at Pamukkale, Turkey. The salts in the water have crystallizedto create a magical landscape of “frozen” waterfalls, stalactites, and basins. People have come to bathe in its warm waters since ancient times.11DK GUIDE TO S AVAGE EARTHERUPTION!Wcarbon dioxide gas. Immense underground pressures trap theHEN A VOLCANO BLOWS ITS TOP , it gets its explosive power fromgas in the magma and keep it in a dissolved form. With the sudden release of pressure that occurs when a