130 likes | 139 Views
Discover the fascinating world of volcanoes - from magma chambers to ash clouds. Learn about different types of eruptions and how they form, with examples like Mauna Kea and Mount Fuji.
E N D
Volcanoes! • What is a Volcano? • A volcano is any opening in the Earth’s crust where magma, ash and gas are able to reach the surface • Volcanoes may have more than one opening which are called vents • The main vent is known as the crater
Volcanoes! • What is a Volcano? • Far below the crater is the magma chamber • Magma rises from the magma chamber, through a conduit, into the throat of the volcano, until it reaches the crater
Volcanoes! • Large Magma Chamber • Bedrock • Conduit (pipe) • Base • Sill • Dike • Layers of Ash Emitted by the Volcano • Flank • Layers of lava emitted by the Volcano • Throat • Parasitic Cone • Lava Flow • Vent • Crater • Ash Cloud
Volcanoes! • What Causes Volcanoes? • Volcanoes are caused by one of three things: • Convergent tectonic plates, usually at a continental-oceanic plate subduction zone • Divergent tectonic plates, usually at a mid-oceanic ridge • Mantle plumes a.k.a. “hot spots”
Volcanoes! • Three Major Types of Volcanoes • Shield Volcano • Broad with gentle slope similar to a shield • Produced by low-viscosity lava flows • Mild eruptions • More common in oceanic than continental settings
Volcanoes! Mauna Kea in Hawaii
Volcanoes! • Three Major Types of Volcanoes • CompositeVolcano (Stratovolcano) • Tall with steeper slopes similar to a cone • Produced by high-viscosity lava flows • Explosive eruptions of alternating layers of ash, cinders and lava • More common in subduction zones
Volcanoes! Mount Fuji in Japan
Volcanoes! Mount Mayon in Phillipines
Volcanoes! • Three Major Types of Volcanoes • Cinder Cone • Small with steepest slopes • Produced by explosive lava flows • Violent eruptions • Commonly found around shield or composite volcanoes
Volcanoes! Sunset Crater in Arizona
Volcanoes! Capulin Volcano in New Mexico