Built to Last

Built to Last — page 3 — Earth is made of several layers The surface of the Earth is called the crust Although the Earth's surface looks thick and strong it is really quite thin The thickest part of the Earth's crust is only about 60 miles 97 kilometers thick The mantle lies under the surface The mantle is a layer of molten or melted rock The core is at the center of the Earth The core is made of metal and is about 44,000 miles 70,811 kilometers in diameter 6

Built to Last — page 4 — Did You Know The Earth's crust is thinnest under the oceans The crust there is only 4 to 7 miles 6 4 11 3 kilometers thick The Earth's crust is thickest under the continents Mantle Core Crust 7

Built to Last — page 5 — North American plate Eurasian Eurasian plate Caribbean Pilipino plate plate Arabian plate сосов plate FOLTOR Pacific plate Nazca plate Australian plate South American Indian plate African plate plate Australian plate Scotia plate Antarctic plate This map shows the plates on the Earth's surface These plates are in constant motion The edges of these plates known as plate boundaries are where geological events such as earthquakes occur Plate boundaries are also where Earth's features such as mountains volcanoes ocean ridges and trenches are created The land under your feet may seem solid but it is actually moving all the time This movement occurs because the Earth's crust and the outer layer of the mantle rest on flat pieces called tectonic plates The plates move around on top of the mantle Usually this movement is gentle However plates slide and bang against each other causing earthquakes 8

Built to Last — page 6 — Did You Know The Ring of Fire is an area in the Pacific Ocean This area covers about 25 000 miles 40 225 kilometers and includes more than 450 active volcanoes The Ring of Fire is home to 75 percent of the world's volcanic activity and 90 percent of the planet's earthquakes Sometimes hot molten rocks inside the Earth escape through a crack in the surface These cracks are called volcanoes The hot molten rock or lava that flows from a volcano can destroy buildings RING OF FIRE Asia United States of America South America Australia 9

5

PAGE 5 OF 44

›

The only kids' eBook subscription service that offers thousands of high-quality books from well known publishers like HarperCollins, National Geographic and others.

JavaScript Required

Whoops! We're sorry but Epic doesn't work properly without JavaScript enabled. Check your web browser's settings to make sure it's enabled.