how are volcanoes created?
916333
4 ways:\n\nDivergent plate boundaries\nAt the mid-oceanic ridges, two tectonic plates diverge from one another. New oceanic crust is being formed by hot molten rock slowly cooling down and solidifying. In these places, the crust is very thin and eruptions occur frequently because of the pull by the tectonic plates. The main part of the mid-oceanic ridges are at the bottom of the ocean, and most volcanic activity is submarine. Black smokers are a typical example of this kind of volcanic activity. Where the mid-oceanic ridge comes above sea-level, volcanoes like the Hekla on Iceland are formed. Divergent plate boundaries create new seafloor and volcanic islands, such as Cjertce and Hawaii.\n\nConvergent plate boundaries\nIn places where one tectonic plate submerges beneath another, the crust melts and becomes magma. This surplus amount of magma generated in one location causes the formation of the volcano. Typical examples for this kind of volcano are the volcanoes in the Pacific Ring of Fire, and also Mount Etna and Mount Vesuvius.\n\nHotspots\nHotspots are not located on the ridges of tectonic plates, but on top of mantle plumes, where the convection of Earth's mantle creates a column of hot material that rises until it reaches the crust. The temperature of the plume causes the crust to melt and form pipes, which can vent magma. Because the tectonic plates move whereas the mantle plume remains in the same place, each volcano becomes extinct after a while and a new volcano is then being formed as the plate shifts over the hotspot. The Hawaiian Islands are thought to be formed in such a manner, as well as the Snake River Plain, with the Yellowstone Caldera being the current part of the North American plate over the hotspot.\n\nPetitspots\nIn July 2006, volcanoes were discovered that did not fit in any of the above-mentioned categories, since they are located far from the plate boundary, but are too small to be the result of a mantle plume. A new theory suggests that submergence of tectonic plates causes stress all over the plate, which causes the plate to crack in some places. However, other scientists believe the mantle plume theory to be incorrect, and consider this discovery a confirmation of their ideas.
73951
In order for volcanoes to form, there has to be some way for magma to form and pool up.  The "ripping" of plates at spreading zones, and the melting of a subducted plate in subduction zones, can both result in a pool of molten rock.  But there's nothing to cause this to happen at a transform fault, just two plates passing by each other.
253407
True. Magma can be generated at subducted plate boudaries. \n\nI am still uncertain about the question. Does your question read as "Can magma be formed at subducted plate boundaries" then the answer would be yes
263800
Yellowstone volcanics are a localized feature that has shot through the overlying crust.  This is determined largely through geochemestry and heatflow studies.  The Hawiaan Islands are formed as a result of a hotspot.  You can see that the overlying plate has been moving with respect to the hotspot because the islands formed one at a tine in a line, showing plate direction.\n\nMt St. Helens is the result of a process called subduction.  The oceanic Pacific plate is being shoved underneath the North American plate.  As that plate is pushed deeper and deeper, heat and pressure create a partial melt that can rise to the surface and create volcanoes.  Look at the Aleutian chain, those are also subduction volcanoes, only there you see oceanic crust shoved under oceanic crust
225608
Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from either the Earth's mantle or pre-existing rocks made molten by extreme temperature and pressure changes. Over 700 types of igneous rocks have been described, most of them formed beneath the surface of the Earth's crust. The word "igneous" is derived from the Latin ignis, meaning "fire".\n\nIgneous rock are classified according to mode of occurrence, texture, chemical composition, and the geometry of the igneous body.\n\nIgneous rocks make up 95% of the Earth's upper crust.
448232
Depends on the composition of the magma.\n\nMagma high in silica tends to be thick & gas bubbles are trapped. The gas builds up & boom! Explosion.\n\nBasaltic lava tends to be "soupy" so that the gas bubbles escape. No explosions here.\n\n:)
305725
Yes, the seismic activity that causes one can also cause the other.  When the Earth's techtonic plates shift but experience some resistance, they shake, jump, rattle the area around that resistance.  Sometimes a crack in the Earth's crust is created or widened which creates the eventual environment for a volcano.  Othertimes volcanoes are created over a hot spot (thin crust) in the Earth's crust, like the Hawaiian islands.  This is somewhat different, although some tremors can be felt.
71801
It depends on the volcano.\n\nIf magma - molten rock - is erupted it forms new formations when it cools. On the big island of Hawaii, the volcanic eruptions have added a lot of new land to the island.\n\nIf it is a pyroclastic flow - fast, hot gasses and volcanic debris -  like the one that destroyed Pompeii or Mt. St. Helens, there may not be any new land created and the existing land will be radically altered.\n\nIn general, when a land based volcano erupts, the lava and stone and ash build up around the eruption site into a cone shape.\n\nUndersea volcanos spweing lava also build up, but not in a cone shape. Once the hot rock hits water it starts to cool into large pillow-shaped forms.
20175
Geologists classify volcanoes in following ways:\n\nCinder cones are the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone. Most cinder cones have a bowl-shaped crater at the summit and rarely rise more than a thousand feet or so above their surroundings. Cinder cones are numerous in western North America as well as throughout other volcanic terrains of the world.\n\nSome of the Earth's grandest mountains are composite volcanoes--sometimes called stratovolcanoes. They are typically steep-sided, symmetrical cones of large dimension built of alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs and may rise as much as 8,000 feet above their bases. Some of the most conspicuous and beautiful mountains in the world are composite volcanoes, including Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Shasta in California, Mount Hood in Oregon, and Mount St. Helens and Mount Rainier in Washington.\n\nShield volcanoes, the third type of volcano, are built almost entirely of fluid lava flows. Flow after flow pours out in all directions from a central summit vent, or group of vents, building a broad, gently sloping cone of flat, domical shape, with a profile much like that of a warrior's shield. They are built up slowly by the accretion of thousands of highly fluid lava flows called basalt lava that spread widely over great distances, and then cool as thin, gently dipping sheets. Lavas also commonly erupt from vents along fractures (rift zones) that develop on the flanks of the cone. Some of the largest volcanoes in the world are shield volcanoes. In northern California and Oregon, many shield volcanoes have diameters of 3 or 4 miles and heights of 1,500 to 2,000 feet. The Hawaiian Islands are composed of linear chains of these volcanoes including Kilauea and Mauna Loa on the island of Hawaii-- two of the world's most active volcanoes.\n\nVolcanic or lava domes are formed by relatively small, bulbous masses of lava too viscous to flow any great distance; consequently, on extrusion, the lava piles over and around its vent. A dome grows largely by expansion from within. As it grows its outer surface cools and hardens, then shatters, spilling loose fragments down its sides. Some domes form craggy knobs or spines over the volcanic vent, whereas others form short, steep-sided lava flows known as "coulees." Volcanic domes commonly occur within the craters or on the flanks of large composite volcanoes. The nearly circular Novarupta Dome that formed during the 1912 eruption of Katmai Volcano, Alaska, measures 800 feet across and 200 feet high.
134315
There are a couple ways. Hot spots can build up islands through volcanic activity, like Hawaii. Some islands can be created by subduction volcanism (Japan). Other islands can be uplifted at convergent or possibly transverse plate boundaries.\n\nIslands can also be created by erosion and inundation, as in a case of sea level rise where the water covers low lying areas while higher areas get "separated" from the land by water (St. Lawrence Island in Alaska). Glaciers can scour channels around large land masses, then recede and the channels can become filled with water to surround the land masses and make them islands. Manhattan Island was actually created by a continental glacier pushing a bunch of sediment out into the ocean and then receeding (it is a moraine).\n\nSome islands can be created purely by sediment deposition, such as those at the mouths of deltas.
171048
A volcano is a geological landform (usually a mountain) where a substance, usually magma (rock of the Earth's interior made molten or liquid by extremely high temperatures along with a reduction in pressure and/or the introduction of water or other volatiles) erupts through the surface of a planet. Although there are numerous volcanoes (some very active) on the solar system's rocky planets and moons, on Earth at least, this phenomenon tends to occur near the boundaries of the continental plates. However, important exceptions exist in hotspot volcanoes.\n\n \nSmoking Bromo and Semeru volcanoes on Java in Indonesia.The name "volcano" originates from the name of Vulcan, a god of fire in Roman mythology. The study of volcanoes is called vulcanology (or volcanology in some spellings).\n\nMud volcanoes are formations which are often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes, except when a mud volcano is actually a vent of an igneous volcano. This article describes igneous volcanoes.\nhttp://en.wikipedia.org/wiki/Volcano\n\nTo learn more and see images click here\nhttp://volcano.und.edu/volcanoes.html
344523
Well, yeah, there is a relationship.  Most of our recent volcanoes occur near the boundaries of plates.  At mid-ocean ridges hot magma is welling up and cooling to make the plates on either side larger.  Iceland, with its many volcanoes, is on the Mid-Atlantic Ridge.  Where oceanic plates are pushed under other plates (subducted), they are forced deeper into earth where it's hotter, and the subducted plate tends to melt.  The lighter parts of the melt try to work their way toward the surface (because they're less dense, and, hence buoyant), and cause volcanoes such as those of the Pacific's Ring of Fire--Indonesian volcanoes, Japanese volcanoes such as Mount Fuji, Alaska's volcanoes, the Cascade Range in Washington State, and so on.\n\nSome volcanoes are associated with "hot spots", where a plume of magma flows toward the surface, but is not associated with a plate boundary.  The Hawaiian Islands are an example of such a hot spot.  Plate tectonics also affect things here.  The plate moves over the hot spot, continually making new islands.  The newest one hasn't reached the surface yet.  Hawai'i is the newest one that's above the surface, and as you move north and west along the Hawai'ian Archipelago, the islands are progressively older and, because they've had more time to be eroded, smaller.  Northwest of the archipelago are the Emperor Seamounts, islands that were eroded until they no longer reach the ocean's surface.
867639
See for yourself:\n\nhttp://www.solcomhouse.com/volcano.htm\nhttp://volcano.und.edu/vwdocs/frequent_questions/group10_new.html\nhttp://www.exn.ca/volcanoes/causes.cfm\nhttp://vulcan.wr.usgs.gov/Outreach/AboutVolcanoes/where_do_volcanoes_occur.html\nhttp://library.thinkquest.org/10136/volcano/volctq.htm\nhttp://en.wikipedia.org/wiki/Volcano\n\nMore random links I keep at hand for God knows what uses.
86122
I was taught in school that it is due to radioactive decay of elements in the core.  That is pure bullcrap.  If it were true, every time a volcano exploded, there would be radioactive toxins spread out across the world.  Others say gravity pushing on the substances create heat and liquification of earth.  This may be somewhat true.  If you put a piece of solid ice in a chamber and put extreme pressure on it, it turns to liquid.  There must be some other source of internal heat generation though.  I have never found a satisfactory answer to date.  I really don't think anyone knows, just like gravity is still a big mystery.
158817
Several ways. This also depends on the type of eruption. Often earthquakes occur before, or during an eruption causing things to topple. Also, often the size of the volcano itself changes. Lava cools to rock after flowing over the landscape, and kills the organic material it comes into contact with. The gas released during an eruption is also deadly! If it is an eruption like Mt. St. Helens was, the land is covered in ash and decimated by mudslides.
778520
I'm not going to write this in 6 sentences for you but...\n\nIgneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from partial melts of pre-existing rocks in either the Earth's mantle or crust. Typically, the melting is caused by one or more of the following processes -- an increase in temperature, a decrease in pressure, or a change in composition.
536076
You need to include:\n1. A world map of volcanoes. \n2. Statistics about volcanoes (average number of people died from them, how frequently they erupt and destroy things).\n3. Glossy color pictures of volcanoes.\n4. A scientific basis, such as \n.....a question "why do volcanoes occur?"\n.....specific hypotheses as explanations of natural phenomena (a short guess about why volcanoes erupt before the kid does any research, such as "I thought volcanoes erupted because it was like a big pimple. I wasn't sure, so I decided to research this topic.")\n.....research about why (check the Internet, encyclopedia or library)\n.....a conclusion "volcanoes happen because ..."\n.....and "my hypothesis was wrong. I found that volcanoes are not like pimples. They are more like open arteries, because once they erupt they keep spewing until they go dry."\n5. All the good volcano projects have videos of live volcanoes (use an LCD monitor).