VOLCANOES. What is a volcano? Areas of earth’s surface through which magma and volcanic gases pass Magma flows from volcanoes transfer heat and thermal.

VOLCANOES

What is a volcano?Areas of earth’s surface through which magma and volcanic gases pass

Magma flows from volcanoes transfer heat and thermal energy from Earth’s mantle to the surface

What’s inside a volcano?• Volcano comes from the Roman word Vulcan,

which means “fire”

EruptionsExplosive Eruptions

Two products from an explosive eruptionAsh fallPyroclastic materials

EruptionsNon-explosive Eruptions

Characterized by outpouring of lava on to the ground

Three Main Type of Volcanoes

Shield VolcanoShape: Very gentleSize: : Large, over 10 kilometers acrossMaterials: fluid lava flows (basalt)Eruption Type: Quiet

http://www.tourismontheedge.com/places/erta-ale-the-smoking-mountain-of-ethiopia.html

http://mail.colonial.net/~hkaiter/volcanoes.html

Ash and Cinder ConeShape: Steep conical hill with straight sides.Size: Small, less than 300 meters highMaterials: cinders, pyroclastic materialsEruption type: Highly Explosive

Stratovolcano (Composite)MOST COMMON TYPE

Shape: Gentle lower slopes, but steep upper slopes; concave upward

Size: Large, 1-10 kilometers in diameter

Materials: numerous layers of lava and pyroclastics

Eruption type: Explosive

http://curriculum.kcdistancelearning.com/courses/EARTHSCIx-HS-U10/a/unit04/es_4.c.9.html http://www.earthonlinemedia.com/ebooks/tpe_3e/volcanic_landforms/volcano_types_2.html

Other Types of

Volcanoes

Dome VolcanoA dome volcano forms from explosions of material out of the vent and the collapse of material back into vent

http://en.wikipedia.org/wiki/Lava_dome

http://cimss.ssec.wisc.edu/sage/geology/lesson3/concepts.html

CalderaA caldera is a cauldron-like volcanic feature formed

from a much larger depression that forms when the magma chamber empties and its roof collapses.

Crater Lake in Oregon, formed when a caldera filled with water.

http://www.nps.gov/yell/naturescience/caldera.htm

http://curriculum.kcdistancelearning.com/courses/EARTHSCIx-HS-U10/a/unit04/es_4.c.9.html

Fissure VolcanoA fissure volcano forms when lava erupts from long cracks, or fissures, and spreads out evenly (thousands of km)

http://woostergeologists.scotblogs.wooster.edu/2010/02/22/ http://www.inmagine.com/drk008/drk008340-photo