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When a puddle dries up, where does all the water go? The science matters series provides a compelling introduction to key science topics, explaining concepts in a format that encourages reading and comprehension. Each title introduces a core science topic through visual diagrams, hands-on experiments, and fascinating biographies, all engagingly written.
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^Îit%âVVf^ 1 ^^ •':i} ïn- f-^ Studying Volcanoes 4 f What is a Volcano? 6 Moving Earth 8 Earth Erupting 10 Inside a Volcano 12 Near Volcanoes 14 Ir^ Scary Science 16 Volcano Science 18 Surfing Our Earth 20 Science in Action 21 What Have You Learned? 22 Words to Know/Index 24 Í ••' f Studying Volcanoes An erupting volcano is a sight to see. When a volcano erupts, gases and dust fly into the sky. Falling ash and red-hot lava cover large areas. These materials can destroy everything they touch. An erupting volcano can put people who live nearby in great danger. Volcanoes erupt because of powerful forces at work deep inside Earth. Scientists are not sure what causes these forces to occur. They study volcanoes to solve this mystery. • Kilauea is a volcano located on the southernmost island of Hawai'i. It is one of Earth's most active volcanoes. Volcano Facts Did you know that the circular, funnel-shaped opening at the top of a volcano is called a crater? Read on to learn more about volcanoes, lava, and volcanic eruptions. • Materials spurting out of a volcano are very hot. They are about 2,000° Fahrenheit (1,093° Celsius). This is hot enough to cook a hot dog in one second! • Lava can travel 120 miles (193 kilometers) per hour. • Lava is magma that has come to Earth's surface.There are two kinds of lava. Fluid lava, called pohoehoe, flows quickly. Sticky lava, called a'a, moves more slowly. • Earth's largest volcano is Mauna Loa. It rises 2.5 miles (4 km) above sea level. Mauna Loa covers about half of the island of Hawai'i. • Volcanoes helped create Earth.They added new rock to the land and gases to the atmosphere. • Some people choose to live near volcanoes.This is because the land is good for farming. What is a Volcano? A volcano is an opening in Earth's surface. Magma and gas rise through the opening and burst forth. The opening is usually found at the top of a coneshaped mountain. These mountains are often called volcanoes, too. Volcanoes are not all the same. They can look very different. Layers of magma form volcanoes. The size and shape of a volcano depend on the magma's thickness. The type and timing of eruptions also change how volcanoes look. \ • Crater Peak is on Mount Spurr in Alaska. It began erupting at least 6,000 years ago. Types of Volcanoes Scientists group volcanoes into three main types. The types are cinder cones, composite volcanoes, and shield volcanoes. J^ ' ' 'v Cinder cones are steep and cone-like in shape.They are formed from tiny, glassy pieces of volcanic rock.These pieces settle around the vent. __ Composite volcanoes are also coneshaped.They are larger than cinder cones because they have erupted many times from the same vent. Composite volcanoes are made from alternating layers of lava, volcanic ash, and cinders. Cinders are pieces of coal, wood, or other material that is still hot and glowing but no longer burning. Shield volcanoes look like large mounds.They are formed by fluid .^ I lava made of basalt.This kind of «,. r . ' /.' lava flows quite far. It creates softsloped mountains. Moving Earth Earth's surface is made of a thin layer of roc