CHAPTER ONE What Are Nature's Forces Nature is usually calm and quiet Most people on Earth go about their days feeling safe and secure However nature sometimes gets out of control Sometimes nature's forces unleash destruction on the planet we call home The forces that destroy are the same ones that formed our planet and affect our lives 4
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
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
