Volcanoes Luis Viadas Physical Geography 110 November 29, 2011
What is a Volcano?A Volcano is a mountain or hill, typically conical, havinga crater or vent through which lava, rock fragments, hotvapor, and gas are or have been erupted from theEarth’s crust.The basic parts that make a volcano are the magmachamber, conduit, branch pipes,throat, summit, vent,and layers of lava and ash emitted by the volcano.
Volcanic FeaturesThe features of a volcano depend on various factors.Such as the way lava comes out of it and the way iterupts. Some volcanoes have rugged peaks and othershave summit craters. Some different types of volcanicformations are shield volcanoes, lava domes, andcryptodomes. Shield volcanoes are formed when lavais slowly pushed out. Lava domes are formed whentheir is a violent eruptions. Cryptodomes are formedwhen a violent eruptions occurs and a bulge is forced.
Volcanic EruptionMagma collects under the earths surface inmagma chambers. Since the liquid magma isless dense than the rock the pressure pushesthe magma to erupt through the surface.Volcanic eruptions can also occur when theEarth’s plate collide with each other and pushthe magma towards the Earth’s surface throughﬁssures and volcanic vents.
Magma & LavaMagma is a mixture ofmolten rock and othersolids found beneath theEarth’s surface and insidethe volcano. Itstemperature ranges from700 to 1300 degreescelsius. Lava is the namegiven to magma when it isalready erupted and on theEarth’s surface.
Classifications of VolcanoesActive- Active volcanoes are those that erupt frequently.Scientist consider a volcano to be erupting if it showssigns of gas emission or earthquake activity.Extinct- Extinct volcanoes are volcanoes that are veryunlikely to erupt because they no longer have a magmasupply.Dormant- Dormant Volcanoes are ones that haveerupted in historical records, but do not have recenterupting activity.
The Affect of Volcanoes on PeopleResearch shows that 1 in 10 people in the world areconsidered to live in a “danger zone” of an activevolcano.Poisonous gases released from volcanic eruptionscause illness and death to people.There has been an estimated 200,00 people to diebecause of volcanic eruptions during the last 500years.
Largest EruptionThe deadliest and largestvolcanic eruption was in1815. It was the Tamboravolcano in Indonesia. Itcaused over 92,000deaths.The eruption caused manychanges in temperatureand atmosphere includingwhat was considered “theyear without summer”.
Volcanoes in CaliforniaTheir 11 are volcanoesis total in California butonly 5 are active.They are MedicineLake, Mount Shasta,Lassen Peak, ClearLake, and Long ValleyCaldera.
Massive Volcanoes Yellowstone is the largest Mauna Lua is the largestsuper volcano and is located volcano in the world and is in Wyoming. located in Hawaii.