Chapter 9 Page 250

 Create a labeled drawing that illustrates what happens when a volcano erupts.

Mt. Etna, one of Italy's (and the world's) most active volcanoesEtna May 10, 2008

 Volcanoes- are areas in the earths surface where magma and volcanic gases exit  Magma- molten rock or liquid rock that is extremely hot

 They form fertile farmland  Create mountains and Islands

 Most common type of eruption  Produce calm flowing lava (in large amounts)  Common on land and ocean floor  Thin runny oozes from vents  What types of lava?  _______________

 Thick and sticky magma will not flow out of volcano.  Instead, it plugs the vent like a cork in soda bottle. Dissolved gases cannot escape, build up pressure until they explode.  Clouds of hot debris and gases shoot out from the volcano, often at supersonic speeds. Molten rock is blown into millions of pieces that harden in the air.

TERMS TO KNOW  Lava is magma once it exits a vent  The vent is any opening on the surface were volcanic materials escape  Magma Chamber – a body of molten rock under the earth surface Vent Lava

 Water stays dissolved in magma only when it is extremely hot and under pressure  As magma moves to the surface it cools and pressure decreases water and CO2 turn to gas state  This causes lava to become explosive  Pumice –Lava filled with gas and can float on water

 High levels of Silica also cause explosive eruptions  Silica  makes magma thick  Lava flows slower  The lava gets stuck in vents  Gases are trapped till pressure builds

 What are the two types of eruptions and describe them.  Try to Illustrate each

 Lava  Liquid magma (or molten rocks)  Normal found in non explosive eruptions  Four Main types  Aa  Pahoehoe  Pillow lava  Blocky lava  Pyroclastic Material  Lava is blasted into the air and has time to cool and harden  Normally present in explosive eruption  Four Main types  Volcanic Bombs  Lapilli  Volcanic Ash  Volcanic Blocks

High Viscosity Low Viscosity Moves Quickly Moves Slow

Lapilli (lah PIL IE) Tiny pebble like pieces of lava that harden before hitting the ground Volcanic Bombs Large blobs of magma that form in the air Volcanic Ash Forms when gases in magma expand rapidly Volcanic Blocks Largest pieces of volcanic material. Solid rock erupting

 Very dangerous  Enormous amounts of hot ash, dust and gases are ejected form volcanoes  Temp can be more than 700°C  See page 255  video

 Put Your Name on The Front  Three types of volcanic eruptions  Describe each type (list things seen in each)  3-4 facts  Draw a image or print one from the internet for HW  Label important parts on each image  Ex (lava, debris, gas, rocks)

 Give me an example of two solutions label one high viscosity and the other low  What are two the main groups of things that erupt from a volcano

1. Aa 2. Pahoehoe 3. Pillow lava 4. Blocky lava 5. Volcanic Bombs 6. Lapilli 7. Volcanic Ash 8. Volcanic Blocks Front Back AA (Name of object) Two important fact describing If it is lava or pyroclastic material

 List the type of eruptions starting with most dangerous ending with least dangerous?  Tell why you consider one most dangerous? Because the book or notes said so is not an answer.