The word "volcano" comes from the little island of Vulcano in the Mediterranean Sea off Sicily (Italy). Centuries ago, the people living in this area believed that Vulcano was the chimney of the god Vulcan ( he was the blacksmith of the Roman gods -- he made things out of metals). They thought that the hot lava pieces and clouds of dust erupting from Vulcano came from Vulcan's furnace as he made thunderbolts for Jupiter, king of the gods, and weapons for Mars, the god of war. In Polynesia the people attributed eruptive activity to the beautiful but wrathful Pele, Goddess of Volcanoes, whenever she was angry or spiteful. Today we know that volcanic eruptions are not super-natural but can be studied and interpreted by scientists. VOLCANOES

Volcanoes are mountains, but they are very different from other mountains; volcanoes are built by the accumulation of their own eruptive products -- lava, bombs (hardened lava blobs), ashflows, and tephra (airborne ash and dust). A volcano is most commonly a cone shaped hill or mountain built around a vent that connects with pockets of molten rock (magma) below the surface of the Earth. The term volcano also refers to the opening or vent through which the molten rock and associated gases are expelled. So, What is a volcano?

What Does a Volcano Look Like? In your packet, draw what you imagine when you think of a volcano. Look at the next few slides. Decide whether each picture is of a volcano (yes or no). click to continue…

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How did you do? If you answered yes to every picture, then you got them ALL correct! Every picture was of a volcano … are you surprised? Many people think that all volcanoes look something like this

TYPES OF VOLCANOES As you may have already figured out, there are different types of volcanoes. The 3 types are: 1. Shield 2. Cinder Cone 3. Composite (or Stratovolcano)

Shield Volcanoes A shield volcano is a large, gently sloped volcano Materials Erupted: mainly liquid lava, so the volcano is made of layers of hardened lava. –Non-explosive eruptions Example: the volcanoes of Hawaii

Cinder Cone Volcanoes A cinder cone volcano is a relatively small, steeply sided volcano. These volcanoes often have a visible crater. Materials Erupted: small pieces of hardened lava (rock fragments) - called cinders –Moderately explosive Example: Paricutin (Mexico)

Composite Volcanoes A composite volcano is a huge mountain-like volcano. Materials Erupted: sometimes lava, sometimes rock fragments. –May have very explosive eruptions Example: Mount St. Helens

Volcano Types Look at the following slides. In your packet identify each volcano as … *shield *cinder cone *composite (stratovolcano)

Picture A click here to proceed

Picture B click here to proceed

Picture C click here to proceed

Picture D click here to proceed

Picture E click here to proceed

Picture F click here to proceed

How did you do? A = composite (Mount Rainier, WA) B = shield C = composite (Popocatepetl, Mexico) D = cinder cone (Paricutin, Mexico) E = shield (Mauna Loa, Hawaii) F = cinder cone (Papua New Guinea) Click green button to return to volcano picture The green button in the lower left of volcano picture will return you to this screen

Terms to know … Caldera - A caldera is a large, usually circular pit at the peak of a volcano. It forms when a volcano erupts violently. If enough magma erupts there is nothing to hold up the volcano - this leads to the collapse of the volcano and the formation of a large pit.

V ent Vents are openings in the Earth's crust from which molten rock and volcanic gases escape onto the ground or into the atmosphere. Vents may consist of a single circular-shaped structure, a large elongate crack or a tiny ground crack.

VOLCANIC ACTIVITY ACTIVE - A volcano that has erupted in the recent past and is expected to erupt again. DORMANT - A “sleeping” volcano. A volcano that has not erupted in the recent past, but could erupt again. EXTINCT - A volcano that is not expected to erupt again. Click to continue …

Volcano Research You will be assigned a volcano to research. Each volcano has something interesting and unique about it - find out what it is! For each volcano you will be researching *where the volcano is located *when the famous eruption occurred *what type of volcano it is *what is unique or interesting about the volcano *is the volcano active, dormant or extinct Ask your teacher for a research form and begin! Some helpful websites are listed on the next slide …

Volcano World U.S. Geological Survey - volcano page Info. on Mount St. Helens Info. on Mount Rainier Volcanoes Listed by Name Hawaii Volcanoes Smithsonian Volcano PageVolcanoes Live Encarta (type in volcano name) Encyclopedia.com (type in volcano name) Try these sites to get your research started