* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Explosive eruptions
Itcha Range wikipedia , lookup
Mount Garibaldi wikipedia , lookup
Mount Meager massif wikipedia , lookup
Llullaillaco wikipedia , lookup
Mount Pleasant Caldera wikipedia , lookup
Level Mountain wikipedia , lookup
Mount Pinatubo wikipedia , lookup
Craters of the Moon National Monument and Preserve wikipedia , lookup
Lascar (volcano) wikipedia , lookup
Olympus Mons wikipedia , lookup
Mount Edziza volcanic complex wikipedia , lookup
Cascade Volcanoes wikipedia , lookup
Wells Gray-Clearwater volcanic field wikipedia , lookup
Volcanology of Io wikipedia , lookup
Shield volcano wikipedia , lookup
Mount St. Helens wikipedia , lookup
Nevado del Ruiz wikipedia , lookup
Mount Vesuvius wikipedia , lookup
Mount Pelée wikipedia , lookup
Silverthrone Caldera wikipedia , lookup
What is a volcano? • A weak spot in the crust where magma has come to the surface. http://alaskadestination.com/alaska-volcano-images/ What is volcanism? • Any phenomena associated with volcanic activity. • What volcanic phenomena have you heard of? What are some of the things that can happen during an explosive eruption ? • Explosion breaks lava into fragments of different sizes. a. volcanic ash b. cinders c. bombs http://www.gc.maricopa.edu/earthsci/imagearchive/b ombs.htm • Pyroclastic flow: a mixture of hot gases, ash, cinders, and bombs. http://www.volcano.si.edu/volcanoes/region15/peru/ubinas/3110ubi7.jpg What is pahoehoe? • Lava that flows easily and hardens into a rippled surface. http://seismo.berkeley.edu/~manga/EPS214/rope.jpg What is A’a? • Flows slowly and hardens into rough chunks. http://www.decadevolcano.net/photos/keywords/a_a_lava.htm http://www.livingwilderness.com/hawaii/hawaii-pahoehoe-flow.html http://volcanoes.usgs.gov/hazards/lava/index.php http://www.earlham.edu/~bestan/Graphics/aa1.jpg http://stevekluge.com/geoscience/images/ How many active volcanoes are there? • There are about 600 on land and more under the ocean where it is hard for scientists to observe or map them. What causes a volcano to erupt? • Dissolved gases are trapped in magma. As the magma rises, the pressure decreases, and the gases expand causing bubbles that increase in size as they rise to the top. The bubbles push the magma from the chamber into the pipe until it comes out a vent. What is a quiet eruption? • Quiet eruptions: Gases in thin magma bubbles out gently. • Produce both pahoehoe and a’a. • Ex: Hawaiian Islands What is an explosive eruption? • Explosive eruptions: thick magma plugs volcano’s pipe like a cork. • Ex: Mt. St. Helens What is the life cycle of a volcano? • • • Active: one that is erupting or showing signs of erupting Dormant: scientists expect eruption in the future Extinct: unlikely to erupt again. http://maps.unomaha.edu/Peterson/funda/Pictures/Japan-2/Japan_files/image001.jpg Mt Fuji in Japan What kind of landforms are made by volcanoes? Diamond Head, Honolulu, HI Diamond Head is Oahu's largest tuff cone formed over 100,000 years ago by an active bubbling volcano. Nineteenth century British sailors nicknamed the crater Diamond Head when they mistook the calcite crystals for diamonds. A well-graded trail leads you up the 760-feet summit to a World War II bunker with a bird's eye view of Honolulu. (http://commons.wikimedia.org/wiki/File:Diamond-HeadHawaii-Nov-2001.jpg) Mauna Kea is a shield volcano. http://cimss.ssec.wisc.edu/sage/geology/lesson3/concepts.html Lava Pillow Lava Tube, Vocano National Park, Hawai’i http://www.traveltohawaiireviewed.com/bigisland/Attraction/Thurston_Lava_Tube.html A cinder cone - Sunset Crater, AZ http://cimss.ssec.wisc.edu/sage/geology/lesson3/concepts.html Ship Rock, New Mexico is a volcanic neck or plume. http://www.scienceclarified.com/landforms/Ocean-Basins-to-Volcanoes/Volcano.html Great dikes and sills of pink Zoroaster granite intrude the nearly black, crystalline Vishnu schist, rising in precipitous, jagged cliffs over thirteen hundred feet above the Colorado River. http://www.rockhounds.com/grand_hikes/geology/overview.shtml Lava plateau in Colorado. http://www.photos-of-the-year.com/contest/08/potm/showphoto.php?photo=1459 Mount St. Helens in Washington State is an active composite volcano. http://www.worldbook.com/wb/Students?content_spotlight/volcanoes/how_kinds Crater Lake caldera in Oregon. http://www.swisseduc.ch/stromboli/glossary/caldera-en.html Half Dome Mountains in Yosemite national Park, CA http://www.answers.com/topic/batholith Hot Springs National Park in Arkansas http://www.viewpoints.com/Hot-Springs-National-Park-review-11871 Castle Geyser in Yellowstone National Park http://geology.about.com/library/bl/images/blgeyser.htm