Describe the different kinds of underground features caused by volcanoes?
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The primary one is a lava tube, a pathway that magma filled and left after cooling, long tunnels that are a way of magma flowing out of the central vent area.\n\nFar underground, you can find the magma chamber, or a solidified magma chamber- a pluton.
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Volcanoes occur in hotspots where the earths crust is thin, most often around subduction zones, or areas where the tectonic plates are colliding and one plate is sliding under the other. There are other places where volcanos or hotspots occur, such as Hawaii, but in that case the chain of islands known as Hawaii are being pushed north by the movement of the tectonic plate there. In fact right now there is another island being built beneath the ocean just south of the main island. The earth is slowly cooling though events such as these. Beneath the crust the magma is under intense pressure and it has to escape somewhere, so it does escape at these weak places in the earths crust which we call volcanos.\n\nOf course I could have just plagarized my answer like  mikah_nine, but instead I opted to answer from my own knowledge and even include a source.
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Heres a few places to start with;\nhttp://www.volcanolive.com/mehetia.html\nhttp://www.swvrc.org/cerupt.htm\nhttp://volcano.und.nodak.edu/vwdocs/volc_images/Mehetia.html
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Probably through volcanic undersea eruptions.
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volcanoes and earthquakes (faults)
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volcanic crater - a bowl-shaped opening at the top of a volcano, its that opening from which lava, gases, and ejecta ..\n\nfrom the wikipedia : Perhaps the most conspicuous part of a volcano is the crater, a basin of a roughly circular form within which occurs a vent (or vents) from which magma erupts as gases, lava, and ejecta. A crater can be of large dimensions, and sometimes of vast depth. Very large features of this sort are termed calderas. Some volcanoes consist of a crater alone, with scarcely any mountain at all; but in the majority of cases the crater is situated on top of a mountain (the volcano), which can tower to an enormous height. Volcanoes that terminate in a principal crater are usually of a conical form.\n\nOn Earth, volcanic explosion craters are often formed when magma rises through water-saturated rocks and causes a phreatic, or steam explosion. Volcanic explosion craters from phreatic eruption often occur on plains away from other obvious volcanoes. Other volcanic eruptions can cause mild explosions, often in a series of events. Some volcanic craters form by collapse with little or no explosive activity. Volcanic craters are typically seen either on the summits or on the flanks of volcanoes. Volcanic craters have also been identified on the Moon, Mars, Venus, and Io.
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...a composite volcano.\nThese types of volcanoes are built up of layers of lava, ashfall, tephra, cinder, etc.   One name is stratovolcano (strato- refers to the layers, and the other is composite, which refers to the fact that the volcano is made up of many types of material.\nFor more information on stratovolcanoes:\nhttp://vulcan.wr.usgs.gov/Glossary/StratoVolcano/description_composite_volcano.html
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1 (People see the volcano with some smoke over it)\n2 (they do not believe their eyes, "Wow, let's come a bit closer and watch the fire"  - they say)\n3 (The top of volcano collapses down)\n4 (A large opening is proclused)\n5 (Magma forced upward earth's surface)\n6 (Poor people, they were too curious)
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They primarily occur in shield volcanoes & volcanic fissures.\n\nThe most notorious of these are found in Hawaii.\n\nBasaltic lava is made up of mostly of darker minerals such as magnesium & iron. It usually is lower in gas content & is less viscous than andesitic or felsic magmas.\n\nTwo major types of basaltic lava exist: Pahoehoe & A'a.\n\nPahoehoe is ropy & runny in nature while A'a is more brick-like. The names sound appropriate, don't they?\n\nThe type/shape/size of a volcano is determined by the kind of lava that extrudes from it. So basaltic lava is associated w/ shield volcanoes.\n\nShield volcanoes located w/in the U.S. include Cascade range in Oregon & Hawaiian volcanoes.\n\nHope this helps.\n\n:)
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Volcano is the result of Lava and gases gushing out of the surface of the earth at great heat and pressure.  The molten lava is running over the land and destroy the plants and trees and after cooling becomes rock there. Fresh lava  comes out and run in the available slope.  The result is a mountain is growing with fire and lava.  Thus the mountains are the result of volcano and lava.  When the pressure within the volcano is reduced the volcano takes rest.It will erupt at any time  and send lava and gases, fire in all the directions.  The centre of the earth is believed to contain very hot lava and gases which is likely to come out at any time in any part; and most likely in the soft surfaces .
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When pressure from magma attempts to reach the surface, and is blocked by a "plug" of rock and other debris formed from earlier eruptions. The magma contains a lot of gas, so this, too, will add to the pressure on the plug, and eventually the pressure will become so great that it must be "relieved", hence causing an eruption (this is the more explosive type). A lesser type, involving lava eruptions, is when magma reaches the surface through breaks (faults, vents or fissures). There are other types of eruptions, like steam eruptions, or geysers (think of Yellowstone and Old Faithful), that can occur with any volcano. These mini eruptions are a result of water seeping into dormant fissures and making contact with magma below the surface. The water is instantly evaporated by the super-hot magma, and steam rises and shoots out from the open vent.
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High pressure builds up inside the magma chamber due to gases & the actual heat inside.\n\nComposite volcanoes usually are the worst for explosive eruptions b/c of the amount of trapped gases that build up. They erupt lava that is high in silica which also makes it thick. This combination usually leads to deadly pyroclastic flows.
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go to\nhttp://en.wikipedia.org/wiki/Volcanoe
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The answer is: D. Volcanoes that have large amounts of silica\n\nHere is the reason why it is D:\n\nMagma that contains high amounts of silica is very viscous. That means it is very thick. Because of its thickness, gases can not escape & will build up behind the magma. When the pressure builds up enough, an explosion occurs. Large chunks of lava rock are thrown from the volcano in all directions. The debris fallout from these types of eruptions is extremely dangerous!\n\nIn 1980, Mt. St. Helens was an explosive composite volcano. Half the mountain was gone in a matter of minutes. The problem with that particular volcano was not the falling rock debris (few people). In fact w/ St. Helens, it was the ash which is small particles of volcanic glass (a.k.a. silica). These minute particles of glass can cut your lungs. Also, people living & camping down below the mountain were caught up in mudflows caused by the melted snowcaps. Also, pyroclastic flows can race down the mountainside at tremendous speeds. Anyone caught in the way would be annihilated.\n\nSea water can cause explosive steam eruptions but this occurs in submarine volcanoes (underwater). No one is around to be in its way.\n\n:)
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types of volcanoes:\n1. shield\n2. composite/strato\n3. caldera\n4. MORB\n \ntypes of eruptions\n1. Strombolian\n2. Vulcanian \n3. Vesuvian\n4. Pelean\n5. Hawaiian\n6. Hawaian\n7. Icelandic\n8. plinian
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D. Fissure eruptions\nand it also happens mostly under water.
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In a phrase, volcanic rock.\n\nEach volcano erupts constructively and destructively, and some of those constructive eruptions build the sides of the volcano.  The type of magma determines the color and shape.