4. Home hypertext map slide 3 Volcanoes slide 1 Introduction slide 2 The Earth inside out slide 4 Long ago slide 5 The Pangaea slide 6 Earths plates slide 7 Continental drift slide 8 Formation slide 9 How a volcano begins slide 10 Why? slide 11 Vulcan Slide 12 A volcanologists Slide 13 Where are the volcanoes? Slide 14 Volcano theory slide 15 Sing a song slide 16 MAP MAP Hypertext The End slide 17

6. FOR MANY YEARS IT WAS BELIVED THAT THE LOCATION OF THE CONTINENTS WAS FIXED. IT WAS BELIEVED THAT CONTINENTS WERE SIMPLY AREAS WHERE THE CRUST WAS TO HIGH FOR THE OCEAN TO COVER THEM ALL.

7. In 1915 it was hypothesized that there was an original supercontinent which was named Pangaea, meaning "All- land,. It began breaking up during the TRIASSIC (late period). TRIASSIC

8. The plates are made of rock and drift all over the globe; they move both horizontally and vertically. Over long periods of time, the plates also change in size as their margins are added to, crushed together, or pushed back into the Earth's mantle.plates

11. Deep in the Earth it is very hot. It is so hot that rocks melt. The melted rock is called magma. The magma is lighter than the rocks around it, so it rises. Sometimes it finds a crack or hole in the Earths crust and bursts through.

12. WHY PressurePressure builds deep in the Earth where the magma is. Suddenly the gases escape and violently explode. It is a kind of toothpaste squirting out of a tube when you give it a hard squeeze Pressure builds deep in the Earth where the magma is. Suddenly the gases escape and violently explode. It is a kind of toothpaste squirting out of a tube when you give it a hard squeeze. Pressure

14. ERUPTIONSERUPTIONS Various kinds of Volcano Mr. Stoppato is a volcanologist. Being a volcanologist is one of the most dangerous scientific professions there is. He frequently visits volcanoes to observe volcanic eruptions, collect rock and lava samples. Volcanologists study volcanoes in order to better predict eruptions.

15. COUNT THE TOTAL AMOUNT OF ACTIVE vOLCANOES AND THEN FIND ALL THE PLACES ON A MAP

16. One of the theories about dinosaur extintion says that huge volcanoes erupted, covered the land with lava, and filled the air with huge clouds of dust. The weather changed between unusually hot and cold. Plants died over long periods of time. The plant-eaters died, followed by meat-eaters. By the time eruptions stopped, many plants and animals includinng dinosaurs, were gone.

17. What's it like when volcanoes blow? This is something you ought to know. Pressure builds without interruption and then explodes in a volcanic eruption. When volcanoes erupt, heres what they do: the pressure the pressure makes ash and lava spew. Boulders can get thrown through the air, Move back! dont stand and stare! Its letting off pressure, its not going to wait. Its going to get to that balanced state where forces are equal: equilibrium. Then the pressure starts building up again. What's it like when volcanoes blow? This is something you ought to know. Pressure builds without interruption and then explodes in a volcanic eruption. Remember this from your science classes? A volcanos forces are magma and gases. The underground pressure gets too high and the volcano blows up in the sky. What's it like when volcanoes blow? This is something you ought to know. Pressure builds without interruption and then explodes in a volcanic eruption.

18. Anno scolastico 2010 - 2011 Lavoro svolto dalla classe IV C guidata dallinsegnante Anna Tanimi http://www.scuolaleonardodavinci.it/