Get Ready for an ERUPTION!!! Volcanoes

Volcanos Three Types of Volcanos Shield Cinder Cone Composite

Land Formations from Lava & Ash Shield Volcano Created by hot spots Gently sloping Cinder Volcano Steep Cone-shaped hill/mountain Composite Volcano Tall, cone-shaped mountain Alternating layers of ash and lava

Shield Volcano http://www.earthonlinemedia.com/images/lithosphere/volcanism/shield_volcano_2.gif

Shield Volcano http://www.earthonlinemedia.com/images/lithosphere/volcanism/shield_volcano_2.gif

Ash cinder and bombs erupt explosively to form a cone shaped hill Cinder Cone Ecuador volcanoes, Guagua Pichincha volcano Ash cinder and bombs erupt explosively to form a cone shaped hill http://www.youtube.com/watch?v=aS_xl3nu_mY&NR=1&feature=endscreen

Quiet eruptions alternate with explosive forming layers of lava ash. Composite We made a Shield Volcano, a Cinder Cone Volcano and a Stratovolcano (Composite Volcano). We used baking soda and vinegar in the shield volcano, ammonium nitrate and zinc dust in the cinder cone volcano and ammonium dichromate in the stratovolcano. The eruptions were great! These are the products that we used for the cinder cone volcano: http://www.hometrainingtools.com/zinc-oxide-powder-30-g/p/CH-ZNOXIDE/ and http://www.hometrainingtools.com/ammonium-nitrate-30-g/p/UN1942/ These are the products we used for the stratovolcano:http://www.hometrainingtools.com/ammonium-dichromate-30-g/p/UN1439/ Category: Education License: Standard YouTube License http://facweb.stvincent.edu/academics/pathways/science/volcanoes.htm Quiet eruptions alternate with explosive forming layers of lava ash. http://www.youtube.com/watch?v=1u1Ys4m5zY4

What is a volcano? A weak spot in the crust where molten material, or magma, comes to the surface Magma- molten mixture of rock-forming substances, gases & water from the mantle Lava- Magma that reaches the surface

Where are volcanoes located? Volcanoes can be found: Diverging Plate boundaries (mid-ocean ridge) Converging plates with subduction zones Oceanic plate vs. oceanic plate Oceanic Plate vs. Continental plate Hot Spots Area where magma from deep within the mantle melts through the crust like a blow torch Example: Hawaiian Islands

What is the Ring of Fire? Ring of Fire A circular pattern located around the pacific ocean along the plate boundaries where volcanoes are more common

Results of Volcanoes Are constructive: Can be destructive add new rock to existing land form new islands Can be destructive explosive eruptions changes the landscape of and around the volcano

Eruptions Why do volcanoes erupt? Less dense magma seeps upward through cracks and creates volcanoes Gas in the magma is trapped and builds pressure Closer it gets to surface the less pressure it has and the gases separate (bubbles) Gases dissolve on the surface and magma is carried out

Types of Eruptions 2 types: Quiet Lava moves steadily and easily Explosive Thick, sticky lava plugs vent like a cork and builds up pressure Explodes and releases pyroclastic flow Volcanic ash: fine, rock particles Cinders: pebble sized particles Bombs: baseball to car sized particles

Land Formations from Lava & Ash Shield Volcano Created by hot spots Gently sloping Cinder Volcano Steep Cone-shaped hill/mountain Composite Volcano Tall, cone-shaped mountain Alternating layers of ash and lava

Shield Volcano http://www.earthonlinemedia.com/images/lithosphere/volcanism/shield_volcano_2.gif

Ash cinder and bombs erupt explosively to form a cone shaped hill Cinder Cone Ecuador volcanoes, Guagua Pichincha volcano Ash cinder and bombs erupt explosively to form a cone shaped hill http://www.youtube.com/watch?v=aS_xl3nu_mY&NR=1&feature=endscreen

Quiet eruptions alternate with explosive forming layers of lava ash. Composite We made a Shield Volcano, a Cinder Cone Volcano and a Stratovolcano (Composite Volcano). We used baking soda and vinegar in the shield volcano, ammonium nitrate and zinc dust in the cinder cone volcano and ammonium dichromate in the stratovolcano. The eruptions were great! These are the products that we used for the cinder cone volcano: http://www.hometrainingtools.com/zinc-oxide-powder-30-g/p/CH-ZNOXIDE/ and http://www.hometrainingtools.com/ammonium-nitrate-30-g/p/UN1942/ These are the products we used for the stratovolcano:http://www.hometrainingtools.com/ammonium-dichromate-30-g/p/UN1439/ Category: Education License: Standard YouTube License http://facweb.stvincent.edu/academics/pathways/science/volcanoes.htm Quiet eruptions alternate with explosive forming layers of lava ash. http://www.youtube.com/watch?v=1u1Ys4m5zY4

Where are volcanoes located? Volcanoes can be found: Diverging Plate boundaries (mid-ocean ridge) Converging plates with subduction zones Oceanic plate vs. oceanic plate Hot Spots Area where magma from deep within the mantle melts through the crust like a blow torch Example: Hawaiian Islands

Types of Rocks Produced Type of lava produces different types of rocks Slower Flowing, Thicker, sticky, lighter colored Rhyolite, Pumice, obsidian flows readily, dark colored basalt

Silica Content Determines Rock High Silica – thicker, sticky, lighter colored Rhyolite, Pumice, Obsidian Low silica lava flows readily, dark colored Basalt

Quiet vs. Explosive – determined by TYPE OF FLOW Quiet vs. Explosive – determined by Percentage (amount) of silica (material made from the elements oxygen and silicon)

Stages of a Volcano Active: (live) erupting or has shown signs that it may erupt In the near future Dormant: (Sleeping) is not currently erupting but may/can erupt in the future Extinct: (dead) unlikely to erupt again

Other Volcanic Activity Hot springs Groundwater is heated by near by magma rising to the surface and collects in natural pools

Other Volcanic Activity Geyser Rising hot water and steam that gets trapped underground and builds pressure until it sprays to the surface

Volcano Games http://w4.nkcsd.k12.mo.us/~mkurbin/ptrevgms.htm

Land Formations from Lava & Ash Lava Plateaus Lava moves far from the volcano before cooling which forms high plateaus Calderas Huge hole left by the collapse of a volcanic mountain All magma has been emptied leaving a hollow shell that collapses

Land Formations from Magma Volcanic Neck: magma hardens in the volcanoes pipes and the soft rock wears away Dike: magma that was forced across rock layers hardens and the soft rock wears away Sill: magma that squeezed between rock layers hardens and the soft rock wears away

Land Formations from Magma Batholith Mass of rock formed when a large body of magma cools in the crust Dome Mountains Rising magma is blocked by horizontal rock layers and forces the rock layers to bend upward into a dome shape and then the soft rock wears away

T= Volcanoes TYPES LOCATION (s) ROCKS FORMED/LAVA FLOW -- Shield - layers of lava- gradual hill - quiet -- Composite – Quiet/Explosive – layers ash and lava -- Cinder Cone – Quick Formation - Explosive LOCATION (s) -- Hot Spots -- Ring of Fire (Convergent Boundary) -- Divergent Boundary (MOR-Mid Oceanic Ridge) --Island Arc (Convergent oceanic oceanic boundary) ROCKS FORMED/LAVA FLOW -- Pyroclastic Flow – Cinder, Ash, Rock, Pumice, gases -- Pahoehoe – fast – low silica- low viscosity -- Aa – slow moving, high silica – high viscosity -- Pumice – Light and airy- from explosive eruptions -- Obsidian – more dense and smooth -- Basalt – low silica lava flow

T= VoLCAnoes con’t FLOW & What determines it? --

PARTS OF A VOLCANO --