Contents 4 6 8 10 12 14 16 18 What are Volcanoes Earth's Layers FOCUS ON The Ring of Fire Eruption Shapes of Volcanoes FOCUS ON Mount Vesuvius Underwater Volcanoes Volcanic Rock FOCUS ON Mount Fuji FOCUS ON Mauna Loa Effects of Volcanoes FOCUS ON Eyjafjallajökull FOCUS ON Krakatoa Living near Volcanoes Predicting Eruptions Glossary Test Yourself 20 21 22 23 24 26 28 30 31 Index 32
What are Volcanoes Volcanoes are holes in the Earth’s surface where hot magma and gas from deep underground are released Over time volcanoes grow into tall mountains made from hardened lava and ash There are currently around 1,900 active volcanoes on Earth Mount St Helens page 9 ASIA FOCUS ON Mount Fuji page 20 FOCUS ON Mauna Loa page 21 Mount Pinatubo page 8 FOCUS ON Krakatoa page 24 Location Volcanoes are often found along the boundaries of tectonic plates where sections of the Earth’s crust meet Some volcanoes form at hot spots places where magma inside the Earth is particularly hot There are volcanoes on every continent on Earth 4 PACIFIC OCEAN INDIAN OCEAN AUSTRALIA Plate boundaries
Eruption Active dormant extinct Volcanoes sometimes erupt Lava flows down the sides of the volcano Gas and ash are released into the air When the lava hardens it forms rock Active volcanoes still erupt frequently or are expected to erupt soon Dormant volcanoes are unlikely to erupt again Extinct volcanoes will never erupt again Scientists can measure the amount of magma inside a volcano to determine if it will erupt again soon NORTH AMERICA ATLANTIC OCEAN SOUTH AMERICA EUROPE AFRICA FOCUS ON Eyjafjallajökull page 23 FOCUS ON Mount Vesuvius page 14 Mount Teide page 7 Soufrière Hills page 29 Popocatépetl page 9 In space There are also volcanoes on other bodies in space Io one of Jupiter’s moons has hundreds of volcanoes some of which shoot lava hundreds of miles into the air 5
