Transcript Volcanoes
Volcanoes This lesson is an introduction to all things Volcano. If you fallow the slides, watch the given videos and complete the activity you will be ready to teach this lesson yourself! What are Volcanos? • A volcano is an opening in the earths surface that releases magma, gas and ash from below Where are they Found? • Volcanoes occur along fault lines in the Earth’s plates – The center of the earth is made up on a hot molten CORE – Above the core is the MANTLE which is soft at th bottom then becomes ridged – The top layer is the CRUST is is what makes up plate tectonics – These plates move about 5cm a year How are they made? • Volcanoes occur because of CONVECTION under the earths surface – Convection is pressure under the earths surface • Convection causes pressure along the fault lines->causing magma to erupt through the fault lines Is every Volcano the same? • NO!!! • Volcanoes are ACTIVE, DORMANT OR EXTINCT • There are two different types of volcanoes and they vary by formation-> STRATO AND SHEILD VOLCANOS • They are categorized by their formation but they have many different characteristics Stratovolcano The Stratovolcano comes to a sharp peak at the top and has EXPLOSIVE eruptions Stratovolcano • These volcanoes have quick violent eruptions • During an eruption the volcano spews hot LAVA as well as a PYROCLASTIC flow – These pyroclastic flows travel up to 100 mph and are made up of gases, ash and rock This is Mt St. Helen, located just outside of Seattle it is one of the most active stratovolcanoes in the United States. Shield Volcano Shield Volcanoes have a sloped top and have CONTINUOUS eruptions Shield Volcanoes • These volcanoes have a slow continuous eruption of lava – This makes the volcanos very predictable and easy to get away from if there is an eruption – Many people live on or near shield volcanos THE END Now go to step two and fill in the blanks on the given Concept Map with the information you just learned.