What do we call the Opening of a volcano?
554022
the opening is called the vent,the answer you probably want is the crater as that is the part above ground which you see(big hole).the vent is a gap in the rocks beneath the crater through which the magma passes up from the eruption chamber.
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.
28745
yes and it is due to erupt
950107
Ah... something called a caldera forms.\n\nhttp://vulcan.wr.usgs.gov/Glossary/Caldera/description_caldera.html\nhttp://en.wikipedia.org/wiki/Caldera\nhttp://www.agu.org/pubs/crossref/2003/2003GL018380.shtml\nhttp://hvo.wr.usgs.gov/volcanowatch/1996/96_04_26.html\nhttp://www.yellowstonenationalpark.com/calderas.htm\nhttp://www.mvo.ms/glossary.htm\n\nGosh, if these don't help... I don't know what will.
216094
Scientists have identified four distinct phases of volcanic activity in the formation of Mt. Fuji. The first phase, called Sen-komitake, is composed of an andesite core recently discovered deep within the mountain. Sen-komitake was followed by the "Komitake Fuji," a basalt layer believed to be formed several hundred thousand years ago. Approximately 100,000 years ago, "Old Fuji" was formed over the top of Komitake Fuji. The modern, "New Fuji" is believed to have formed over the top of Old Fuji by around 10,000 years ago. [1]\n\nThe volcano is currently classified as active with a low risk of eruption. The last recorded eruption occurred in 1707 during the Edo period. At this time, a new crater, along with a second peak, named Hōei-zan after the era name, formed halfway down its side.\n\nMt. Fuji is where the Eurasian Plate (or the Amurian Plate), the Okhotsk Plate, and the Philippine Plate meet. They form the western part of Japan, the eastern part of Japan, and the Izu Peninsula respectively.
139985
This from the USGS has all the answers you are looking for:\nhttp://volcanoes.usgs.gov/Products/Pglossary/ShieldVolcano.html\n"Volcanoes with broad, gentle slopes and built by the eruption of fluid basalt lava are called shield volcanoes. Basalt lava tends to build enormous, low-angle cones because it flows across the ground easily and can form lava tubes that enable lava to flow tens of kilometers from an erupting vent with very little cooling. The largest volcanoes on Earth are shield volcanoes. The name comes from a perceived resemblance to the shape of a warrior's shield."\nExamples of shield volcanoes are the volcanoes in the Hawaiian island chain, including Kilauea, Mauna Loa, Haleakala, etc.\nHope this is helpful :-)
717408
Usually there are warning signs that something is happening. Active volcanos such as Mt St Helens are continusly monitored for changes such as increase in earthquake activity, change in the shape of the volcano. Scientists can actually see changes to the shapre of hte volcano by GPS surveys. Like what is happening in the Pacific at teh moment (cant remember the name of the volcano just now) they know something is going to happen, but they cant place a time on it, so they have evacuated hte people. Most people are evacuated before hte volcano blows, but those that have ignored pleas do so at they're own risk. And yes as the dude above me pointed out, by means of a road.
636430
a volcano, long long ago on an island far far away.  I'm sure the real answer is in your textbook.
976524
From the various reading I've done on this subject, as well as the educational programming I've watched about it, I'd say that all things considered, a volcanic eruption, like that of the 1883 explosion of Krakatoa, is by far the most violent and has the most and the longest-lasting consequences not only on the area in which the volcano erupted and the area the lava reached, and not only the areas affected by the resulting tsunamis, its effect actually includes the entire planet, since such an eruption is violent enough to change the entire planet's climate!\n\nWith a volcanic eruption you have: rocks of all sizes, including those the size of houses, hurled out like torpedoes, hot lava that incinerates everything in its path, hot gasses that not only expand, creating a pressure front, not only also incinerate, but also form acids that dissolve the various objects in their path, massive earthquakes, massive tsunamis and last, but most certainly not least, a thick cloud of ash, particles and gasses that wreak utter havoc with the atmosphere and the planet's general climate, thus disrupting wind currents, ocean currents and the general climatic-atmospheric signature of the planet. Consequently, even those places that were nowhere near the volcano, nowhere near the radius of the area the lava will reach, nowhere near any coast that would be affected by the resulting tsunamis, it will still be affected by the falling rocks and debris, which were spewed up into the atmosphere, as well as by the climatic disruptions.\n\nTo my knowledge, not even earthquakes, regardless how violent, can match that level of and extent of destruction, despite the fact that they cause massive fires and potent tsunamis!\n\n\nNote: I took a very "flexible" interpretation of the word storm. I took it to mean any weather/climatic phenomenon/activity. Thus, in that sense, a volcanic eruption can be interpreted as a storm, even though it is not a current of air or water or both!  But, then again, if that type of climatic activity is not to be considered a storm, then what else can it be called? It is ludicrous to lump wind & water weather events together under the title storm, yet consider volcanic eruptions, earthquakes, tsunamis & mudslides, to name a few, categories & titles in of themselves!
50910
Like most of the interior of the earth, the movements and dynamics of magma are poorly understood. However, it is known that an eruption usually follows movement of magma upwards into the solid layer (the earth's crust) beneath a volcano and occupying a magma chamber. Eventually, magma in the chamber is forced upwards and flows out across the planet surface as lava, or the rising magma can heat water in the surrounding landform and cause explosive discharges of steam; either this or escaping gases from the magma can produce forceful ejections of rocks, cinders, volcanic glass, and/or volcanic ash also known as tephra. While always displaying powerful forces, eruptions can vary from effusive to extremely explosive.\n\nMost volcanoes on the land are formed at destructive plate margins: where oceanic crust is forced below the continental crust because oceanic crust is denser than continental crust. As the oceanic crust 'subducts', it is forced into a higher-temperature region called the asthenosphere, and melts. Friction between these moving plates may also be a cause of melting. The reduced density of the melting rock forces the newly formed magma to rise. As the magma rises through weak areas in the continental crust it may eventually erupt as one or more volcanoes. For example, Mount St. Helens is found inland from the margin between the oceanic Juan de Fuca Plate and the continental North American Plate. The oceanic crust is normally a highly-'mafic' (iron and magnesium rich) rock, but as it rises through granitic (more silicic) continental plates, it may cause 'partial melting' of both mantle rocks and the plate rocks, producing magmas of varying silicity. Volcanic arcs forming near subduction zones, on the edges of continental plates, usually form high-silicity (high-viscosity) stratovolcanoes. Examples include the South American Andes and the Cascade range.\n \nA volcano generally presents itself to the imagination as a mountain sending forth from its summit great clouds of smoke with vast sheets of flame. The truth is that a volcano seldom emits either smoke or flame, although various combinations of hydrogen, carbon, oxygen, and sulfur do sometimes ignite. What is mistaken for smoke consists of vast volumes of fine dust (called volcanic ash), mingled with steam and other vapors, chiefly sulfurous. Most of what appears to be flames is the glare from the erupting materials, glowing because of their high temperature; this glare reflects off the clouds of dust and steam, resembling fire.\n\nPerhaps the most conspicuous part of a volcano is the crater, a basin of a roughly circular shape, formed by 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\nVolcanic cones are usually smaller features composed of loose ash and cinder, with occasional masses of stone which have been tossed violently into the air by the eruptive forces (and are thus called ejecta). Within the crater of a volcano there may be numerous cones from which vapours are continually issuing, with occasional volleys of ashes and stones. In some volcanoes these cones form lower down the mountain, along rift zones or fractures. When the cone is eroded these rifts or lava filled fractures remain as radial near vertical dikes of volcanic rock. For example the radiating dikes at Shiprock in NW New Mexico.
810078
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.
102753
Under the continents.  The term refers to the basaultic shields on which the continents "float" on the magma underneath.  When they shift and grind against one another, we have volcanoes and earthquakes.
967908
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.
1084414
Dormant volcanoes are those that are not currently active (as defined above), but could become restless or erupt again. Confusion however, can arise because many volcanoes which scientists consider to be active are referred to as dormant by laypersons or in the media.\n\nExtinct volcanoes are those that scientists consider unlikely to erupt again. Whether a volcano is truly extinct is often difficult to determine. Since "supervolcano" calderas can have eruptive lifespans sometimes measured in millions of years, a caldera that has not produced an eruption in tens of thousands of years is likely to be considered dormant instead of extinct.\n\nFor example, the Yellowstone Caldera in Yellowstone National Park is at least 2 million years old and hasn't erupted violently for approximately 640,000 years, although there has been some minor activity relatively recently, with hydrothermal eruptions less than 10,000 years ago and lava flows about 70,000 years ago. For this reason, scientists do not consider the Yellowstone Caldera extinct. In fact, because the caldera has frequent earthquakes, a very active geothermal system (i.e., the entirety of the geothermal activity found in Yellowstone National Park), and rapid rates of ground uplift, many scientists consider it to be an active volcano.
654850
Until recently, the term "supervolcano" was never used in volcanology. It was coined on TV to refer to those volcanoes that produce massive eruptions able to have a climate impact.
127229
Super Volcanoes are planet killers!!! Yellowstone is the first one that comes to my mind.\n\nHere's what wikipedia says:\n\n"A supervolcano refers to a volcano that produces the largest and most voluminous kinds of eruption on Earth. The actual explosivity of these eruptions varies, but the sheer volume of extruded magma is enough to radically alter the landscape and severely impact global climate for years, with a cataclysmic effect on life.\n\nThe term was originally coined by the producers of the BBC popular science program, Horizon, in 2000 to refer to these types of eruption. That investigation brought the subject more into the public eye, leading to further studies of the possible effects. At first, supervolcano was not a technical term used in volcanology, but more recently, in 2003 and 2004, the term has been used in articles. Though there is no well-defined minimum size for a "supervolcano", there are at least two types of volcanic eruption that have been identified as supervolcanoes: massive eruptions and large igneous provinces."
581208
When there is earthquake around it.\nWhen you start seeing smoke rising.\nWhen you hear a big explosion and see black smoke.\nWhen you see lava coming down it.\n..well, that's the process anyway.