21st Century Skills Library RRReeeaaalll WWWoooRRRlllddd MMMaaattthhh::: NNNaaatttUUURRRaaalll dddIIISSSaaaSSSttteeeRRRSSS VOLCANIC ERUPTIONS by NaNcy RobiNsoN MasteRs Volcanics Eruptions.indd 1 11/17/11 8:45 PM TAbLE Of CONTENTS Published in the United States of America by Cherry Lake Publishing, Ann Arbor, Michigan www.cherrylakepublishing.com Content Adviser Jack Williams Founding editor of the USA Today weather page and author of The AMS Weather Book: The Ultimate Guide to America’s Weather Math Adviser Katherine M. Gregory, M.Ed Credits Cover and page 1, ©Juliengrondin/Dreamstime.com; page 4, ©Andrea Danti/ Shutterstock, Inc.; page 7, ©Sergio Ponomarev/Shutterstock, Inc.; page 8, ©beboy/ Shutterstock, Inc.; page 10, ©Nilanjan Bhattacharya/Dreamstime.com; page 13, ©Jeff Banke/Shutterstock, Inc.; page 14, ©Johann Helgason/Shutterstock.com, pages 17 and 19, ©AP Photo/Michael Probst; page 20, ©Tristan3D/Shutterstock, Inc.; page 23, ©NASA; page 24, ©Sam DCruz/Shutterstock, Inc.; page 26, ©vicspacewalker/Shutterstock, Inc.; page 28, ©Chmpagndave/Dreamstime.com Copyright ©2012 by Cherry Lake Publishing All rights reserved. No part of this book may be reproduced or utilized in any form or by any means without written permission from the publisher. Library of Congress Cataloging-in-Publication Data Masters, Nancy Robinson. Volcanic eruptions/by Nancy Robinson Masters. p. cm.—(Real world math) Includes bibliographical references and index. ISBN 978-1-61080-328-1 (lib. bdg.)—ISBN 978-1-61080-337-3 (e-book)— ISBN 978-1-61080-414-1 (pbk.) 1. Volcanic eruptions—Juvenile literature. 2. Mathematics—Problems, exercises, etc.—Juvenile literature. I. Title. QE522M327 2012 551.2101513—dc23 2011035045 Cherry Lake Publishing would like to acknowledge the work of The Partnership for 21st Century Skills. Please visit www.21stcenturyskills.org for more information. Printed in the United States of America Corporate Graphics Inc. January 2012 CLSP10 Volcanics Eruptions.indd 2 11/17/11 8:46 PM SSSSSS RRRWWWMMM::: NNNAAATTTUUURRRAAALLL DDDIIISSSAAASSSTTTEEERRRSSS NNNNNN OOOOOO IIIIII TAbLE Of CONTENTSTTTTTT PPPPPP chapteR oNe WhAT IS A VOLCANIC UUUUUU ERUPTION? . . . . . . . . . . . . . . . . 4 chapteR two RRRRRR PLOTTINg ThE POWER Of A VOLCANIC ERUPTION . . . . . . . 10 EEEEEE chapteR thRee DO ThE MATh: ASh OVER ICELAND . . . . . . . . . . . . . . . . 14 CCCCCC chapteR fouR DO ThE MATh: OUT-Of-ThIS- IIIIII WORLD ERUPTIONS . . . . . . . . 20 NNNNNN chapteR five COUNT ThE bENEfITS . . . . . . . 24 AAAAAA Real woRld Math challeNge aNsweRs . . . . . . . . . . . . . . . . . . . . . . .29CCCCCC glossaRy . . . . . . . . . . . . . . . . . . . . . . . .30 foR MoRe iNfoRMatioN . . . . . . . . . . . . .31 LLLLLL iNdex . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 about the authoR . . . . . . . . . . . . . . . . .32 OOOOOO VVVVVV Volcanics Eruptions.indd 3 11/17/11 8:46 PM Real woRld Math: NatuRal disasteRs VOLCANIC ERUPTIONS y R a R b i l s l chapteR oNe l i WhAT IS A k s y VOLCANIC R u t ERUPTION? N e c t s 1 w 2 e live on the crust of the earth. The earth’s crust is about 18 miles (29 kilometers) thick. Beneath the crust is a layer of rock called the mantle, which is around It is very hot inside Earth’s deepest layers. Volcanics Eruptions.indd 4 11/17/11 8:46 PM Real woRld Math: NatuRal disasteRs VOLCANIC ERUPTIONS 1,800 miles (2,900 km) thick. Inside the mantle is the earth’s core. Magma, or melted rock, and gas are trapped in the core. A volcanic eruption occurs when magma from deep inside the earth pushes up through the mantle and the crust. Magma that reaches the earth’s surface is called lava. Steam and gases, such as carbon dioxide, are also released into the atmosphere during a volcanic eruption. Volcanologists are scientists who study volcanoes. They place volcanoes in three large categories. An active volcano has had at least one eruption during the past 10,000 years. A dormant volcano has not erupted for some time, but it is expected to erupt again. An extinct volcano has not erupted in the past 10,000 years and is not expected to erupt again. What causes a volcano to erupt? Volcanologists say that eruptions are caused when giant moving slabs of the earth’s crust and upper mantle collide or grind against one other. These slabs are called tectonic plates. As two tectonic plates collide, pressure squeezes magma up between the plates, causing a volcanic eruption. Volcanoes can also erupt when tectonic plates drift apart. Some volcanoes erupt because of weak areas in a plate called hot spots. The volcanoes of the Hawaiian Islands are examples of eruptions from a hot spot. Hawaii’s Mauna Loa is the biggest volcano on earth. It is 60 miles (97 km) long, 30 miles (48 km) wide, and 33,476 feet high (10,203 meters) measured from the bottom of the Pacific Ocean. Volcanics Eruptions.indd 5 11/17/11 8:46 PM Real woRld Math: NatuRal disasteRs VOLCANIC ERUPTIONS y R a R b i l s l l Volcanic eruptions can cause fires, mudslides, floods, i k s avalanches, and earthquakes. Lava flows can reach speeds of y R 90 to 100 miles per hour (145 to 160 kph) as they slide down u t the side of a volcano. These kinds of eruptions can push down N e entire forests. They can change the course of rivers. They c t affect the air we breathe, the food we eat, and the water we s 1 drink. 2 Some eruptions occur suddenly. In 1815, Mount Tambora on the island of Sumbawa, Indonesia, erupted, killing between 70,000 and 90,000 people. The explosion was heard more than LLLiiifffeee &&& CCCaaarrreeeeeerrr SSSKKKiiiLLLLLLSSS Volcanologists have a hot job! They study how and why volcanoes erupt. They also gather and measure samples of volcanic ash and gases. They map lava flows and use problem-solving skills to predict when and where future eruptions may happen. Most volcanologists have college degrees. They must have strong skills in math, science, geography, history, biology, chemistry, physics, and computers. They are often called upon to do hands-on fieldwork, so camping, hiking, and observation skills also come in handy. You can find out more about becoming a volcanologist at the American Geological Institute Web site www.agiweb.org/workforce/careers.html. Volcanics Eruptions.indd 6 11/17/11 8:46 PM Real woRld Math: NatuRal disasteRs VOLCANIC ERUPTIONS Volcanologists travel around the world to learn more about volcanoes. Volcanics Eruptions.indd 7 11/17/11 8:47 PM Real woRld Math: NatuRal disasteRs VOLCANIC ERUPTIONS y R a R b i l s l l 1,200 miles (1,930 km) away. Most of the deaths resulted from i k s starvation and disease. The poisonous gas and ash that filled y R the air and covered the ground made it impossible for crops u t to grow. Thousands died from a lack of food and clean water. N e The massive eruption resulted in climate change in many c t parts of the world. So much ash and other volcanic material s 1 filled the air that it blocked the sunlight, causing a “volcanic 2 winter.” Crops failed and livestock died in many parts of the Northern Hemisphere during what became known as the “Year Without a Summer.” The eruption of Tambora resulted in the worst famine of the 19th century. Some eruptions throw lava high into the air. Volcanics Eruptions.indd 8 11/17/11 8:47 PM