Volcano Presentation Courtney Boyce Justin Watkins and Bridget

Volcano Presentation Courtney Boyce, Justin Watkins and Bridget Egan

What Is a Volcano • A Volcano is an opening or rupture in Earth’s surface or crust that allows ash, magma and gases to escape from bellow Earth’s surface.

3 Areas of Formation • Hot Zones • Spreading Centers • Subduction Zones

Spreading Centers • Area where tectonic plates are diverging • Creates pathway for magma to flow to surface • Some of the magma from these centers will spill out, however, most of the lava cools internally below Earth’s Crust • Mid Oceanic Ridges

Subduction Zones • 2 tectonic plates converge and the more dense of the 2 is subducted. • Usually occurs upon the convergence of an oceanic plate and continental plate because the oceanic plate is dense enough to be subducted. • The descending plate is heated by the pressure and Earth’s heat. This heat and pressure leads to the formation of magma. • Not much volcanic activity at 2 continental plates because continental crust is not dense enough to be subducted.

Hot Zones • Occur in the middle of Plates • Formed by rising magma from deep in Earth’s core so they remain stationary while plates above them move • 50 -100 known hot spots in world • Hawaiian Islands

How Volcanoes are Classified • Shape • Materials they are built of • The way the volcano erupts

Composite Volcano (also known as the strato-volcano) • Formed by alternating layers of lava and rock fragments • Usually they are very big, usually bigger than 2500 m in height, 1000 sq km in surface area and 400 km^3 in volume • Usually erupt in an explosive way this is caused by viscous magma which clogs the volcano’s crater pipe locking gas in the crater pipe, pressure builds up inside the volcano which leads to an explosive eruption

Shield Volcano • Shield Volcanoes are huge in size • Built by many layers of runny lava flows • Lava spills out of a central vent or group of vents and a broad, gently sloping cone is formed • This is because the basaltic lava that flows out of it is very fluid and cannot pile up into steep mounds

Shield Volcanoes (con’t) • They can be produced by hot spots which lay far away from the edges of tectonic plates or along the mid-oceanic range where the seafloor is spreading is in progress and also along subduction related to volcanic arcs • Shield volcanos eruptions are non-explosive some lava-fountaining occurs and forms cinder cones or spatter cones at the vents • Some of the most famous shielf volcanoes are located in Hawaii

Cinder Cones • steep conical hill formed above a vent • eruptions usually don't cause any loss of life • built from lava fragments called cinders. The lava fragments are ejected from a single vent and accumulate around the vent when they fall back to earth. • Cinder cones grow rapidly and soon approach their maximum size. They rarely exceed 250 m in height and 500 m in diameter. • A great example of a cinder cone is Paricuitin Mexico. It was born in February 20, 1943 in a corn field and grew to 300 feet in 5 days.

Spatter Cones • When hot erupting lava contains just enough explosive gas to prevent the formation of a lava flow, but not enough to shatter it into small fragments the lava is torn by expanding gases into fluid hot clots, ranging in size from 1 cm to 50 cm across, called spatter. • When the spatter falls back to Earth the clots weld themselves together and solidify forming steepsided accumulations. These accumulations focused on an individual vent are called spatter cones.

Mt. Vesuvius • Stratovolcano • Status: Active • Location: Italy – Latitude: 40 ° 49’ 14” E – Longitude: 14° 25’ 29” N

Mt. Fuji • Stratovolcano • Status: Active • Location: Japan – Latitude: 35° 21’ 5” N – Longitude: 135° 45’ 1”E

Mt. St. Helens • Stratovolcano • Status: Active • Location: Washington – Latitude: 46. 2° N – Longitude: 122. 21°W

Mt. Etna • Stratovolcano • Status: Active • Location: Sicily – Latitude: 37° 45. 304′N – Longitude: 14° 59. 715′E

Mt. Kilimanjaro • Stratovolcano • Status: Inactive • Location: Tanzania – Latitude: 03° 04′ 33″S – Longitude: 37° 21′ 12″E

Hekla • Stratovolcano • Status: Active • Location: Iceland – Latitude: 63° 59′N – Longitude: 19° 42′W

Chimborazo • Stratovolcano • Status: Inactive • Location: Ecuador – Latitude: 01° 28′ 09″S – Longitude: 78° 49′ 03″W

Mount Cleveland • Stratovolcano • Status: Active • Location: Alaska – Latitude: 52° 49′ 24″N, – Longitude: 169° 56′ 51″W

Mt. Mauna Loa • Sheild • Status: Active • Location: Hawaii – Latitude: 9° 28′ 46. 3″N – Longitude: 155° 36′ 09. 6″W

Volcano Questions • 1. What are three ways that Volcanoes are classified? • 2 -4 Name 3 Famous Volcanos and What type of Volcano they are • 5. What are the four physical components of a volcano? ?

Resources: • http: //www. teachersdomain. org/resources/ess 05/sci/ess/ earthsys/volcanintro/index. html • http: //en. wikipedia. org/wiki/Chimborazo • http: //en. wikipedia. org/wiki/Mauna_loa • http: //en. wikipedia. org/wiki/Cleveland_Volcano • http: //en. wikipedia. org/wiki/Vesuvius • http: //en. wikipedia. org/wiki/Mt. Fuji • http: //en. wikipedia. org/wiki/Mount_Etna • http: //en. wikipedia. org/wiki/Mount_St. _Helens • http: //en. wikipedia. org/wiki/Kilimanjaro • http: //en. wikipedia. org/wiki/Hekla