Volcanoes Ariella WaddellPresentation 311/18/2011

Different Types of Volcanoeshttp://www.eoearth.org/files/110601_110700/110654/300px-AP_ES_Types_volcanoes.jpg

Shield

• Broad• Gently Sloping• Varied Sizes• Layers of Solidified Lava• Basaltic• Quiet Eruptions http://pubs.usgs.gov/gip/volc/fig15.gif

How It’s Formed…

• Created by hotspots, rift and subduction zones• Lava flows constant and slow

http://pubs.usgs.gov/gip/volc/fig14.gif

Composite

• Steep Sided• Symmetrical• Andesitic• Heights over 12,000 Feet• Layers

o Lava Flows o Pyroclastic Materialo Hardened Mudflow

depositshttp://pubs.usgs.gov/gip/volc/fig10.gif

How It’s Formed…

• Common at subduction zones• Magma pulls silica-rich material from the crust

http://pubs.usgs.gov/gip/volc/fig11.gif

Lava Dome

• Small• Heights of Less Than

2000 Feet• Rhyolitic• Explosive Eruptions• Solidified Thick, Viscous

Lava• Irregular Shapes http://pubs.usgs.gov/gip/volc/fig18.gif

How It’s Formed…

• Expansion from below and within• Form in composite volcanoes

http://pubs.usgs.gov/gip/volc/fig17.gif

Cinder Cone

• Small• Steep Sided• Maximum Height 1500

Feet• Loose Pyroclastics• Basaltic• Occasionally Produces

Lava Flowshttp://pubs.usgs.gov/gip/volc/fig8.gif

How It’s Formed…

• Gas rapidly expands causing explosive eruptions• Lava flows up out of the crater and down the sides

http://pubs.usgs.gov/gip/volc/fig9.gif

Effects on the Environment

Gases released after an eruption:•Water vapor•Carbon Dioxide•Sulfur Dioxide•Hydrogen Sulfide•Flourine

http://pubs.usgs.gov/of/1997/of97-262/pinatubo.jpg

Yellowstone Supervolcano

• Three super eruptions• Last super eruption

640,000 years ago• 80 smaller eruptions since• Small chance of eruption

in the next thousand years• 1 in 730,000 chance of

eruption• WI would need gas

masks

http://photonicportal.files.wordpress.com/2011/01/yellowstone-killzone1.jpg?w=500&h=279

http://volcanoes.usgs.gov/yvo/publications/2005/docudrama.php

Formation of the Black Hills

• Caused by uplift• Erosion of

sedimentary rocks• Granite and

metamorphic rocks left behind

http://3.bp.blogspot.com/-aKURgBOaK7w/TenI2NlnwFI/AAAAAAAACpE/QryJRkfST68/s1600/blackHills.jpghttp://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_south_dakota.html

Hotspots

Hawaii Yellowstone

http://www.mnh.si.edu/earth/text/images/4_0_0_0/4252-6.jpghttp://www.punaridge.org/doc/factoids/Hawaii/HawaiiFig2.jpg

Basaltic Silica Rich

References

• http://www.eoearth.org/files/110601_110700/110654/300px-AP_ES_Types_volcanoes.jpg• http://pubs.usgs.gov/gip/volc/fig15.gif• http://pubs.usgs.gov/gip/volc/fig14.gif• http://pubs.usgs.gov/gip/volc/fig10.gif• http://pubs.usgs.gov/gip/volc/fig11.gif• http://pubs.usgs.gov/gip/volc/fig18.gif• http://pubs.usgs.gov/gip/volc/fig17.gif• http://pubs.usgs.gov/gip/volc/fig8.gif• http://pubs.usgs.gov/gip/volc/fig9.gif• http://pubs.usgs.gov/of/1997/of97-262/pinatubo.jpg• http://photonicportal.files.wordpress.com/2011/01/yellowstone-killzone1.jpg?w=500&h=279• http://volcanoes.usgs.gov/yvo/publications/2005/docudrama.php• http://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_south_dakota.html• http://3.bp.blogspot.com/-aKURgBOaK7w/TenI2NlnwFI/AAAAAAAACpE/QryJRkfST68/s1600/blackHills.jpg• http://www.punaridge.org/doc/factoids/Hawaii/HawaiiFig2.jpg• http://www.mnh.si.edu/earth/text/images/4_0_0_0/4252-6.jpg