Joe and Dr Bea’s story Hi My name is Joe I have just returned from another adventure with Dr Bea It was the hottest yet We were on a volcanology mission In case you don’t know volcanology is the scientific study of volcanoes Scientists like us study volcanoes that have a history of erupting so we can try to predict or know ahead of time if and when they might erupt again To do this we have to get quite close to the top of the volcano itself Dr Bea and I knew this could be dangerous Fortunately we had a helping hand from a robot called Dante But let’s start at the beginning 5
ash cloud Before we started our climb Dr Bea wanted to check the slope of the volcano Any change in the slope would be a warning that pressure was building up underground crater vent layers of ash lava flow pipe branch pipe bedrock magma chamber She used a special measuring tool called an extensometer This tool has a laser that can measure even the smallest change in distance As Dr Bea had suspected the slope had shifted Volcanoes can erupt in different ways Ash a cloud of fine particles of minerals spews into the air and rains down on the slopes A pyroclastic flow is a cloud of ash and flames that rushes down the sides of a volcano at a high speed A molten lava flow moves more slowly down the slopes cooling as it goes 6
What is a volcano A volcano is a kind of mountain that actually builds itself It is created when rock deep within Earth gets so hot it becomes molten or turns liquid Called magma it contains heat and gases that force the liquid rock through cracks in Earth’s surface or vents When magma erupts it is called lava Once outside lava cools and becomes a hard gritty rock Layer upon layer can build into a cone-shaped mountain If the lava continues to pour out it can build into an even higher volcano with a tunnel called a pipe running up the center Shapes of volcanoes Tungurahua Volcano in Ecuador sends an ash cloud into the air A shield volcano can rise 27,900 feet 8,504 m high Its sides are not steep and its true height may be hidden if its base is underwater on the ocean floor A stratovolcano also called a composite can rise 8,000 feet 2,438 m high Known for their explosive power some collapse inward creating a massive hole called a caldera A cinder cone can rise 1,000 feet 305 m high It has steep sides and a wide base A cinder cone usually erupts only once Stratovolcanoes can sometimes form lava domes Slow-moving lava builds up inside in mounds near the top until they explode 7
