how is the temperature of hot lava taken?
155392
One method is using bimetallic strips of metals that can stand very high temperature. Bimetallic strips bend when the temperature changes.
23518
Hi Rams, The simple answer is heat, produced by radioactive decay within the Earth. In effect the mantle is a vast heat engine. However, the details have been controversial over the years. Now a picture is emerging, produced by a geophysical technique called seismic tomography. This has imaged subducting slabs of cold dense lithosphere drooping all the way down to the core-mantle boundary. This represents a return flow for convection, affecting the entire mantle. The mantle cools however principally by passive upwelling at mid-ocean ridges. So the mantle contains convection cells. The convection is very slow but relentless, driving the plates at a few cm a year. In essence the plates are just a stiff outer skin, pulled by the subducted slabs. So it is the nature of the outer, cool part of the Earth that organises the convection in the deep Earth. The core-mantle boundary becomes the graveyard of the plates. But plate tectonics only accounts for about 90% of the current Earth heat engine. The other 10% drives from mantle plumes that originate from the core-mantle boundary. Plumes are lava-lamp-like upwellings, although they can take about 100 million years to reach the upper mantle. Plumes are represented on the Earth's surface as "hot-spots" - sites of apparently anomalous volcanic activity such as are found on the Hawaiian islands.\n\nFollowing are links to some excellent resources that answer your query, along with some illustrations :\n\nhttp://pubs.usgs.gov/publications/text/unanswered.html\nhttp://element.ess.ucla.edu/publications/1998_Earth2/1998_Earth2.htm\nhttp://geology.com/plate-tectonics/\n\nMerry Christmas!
379801
This website does all the work.  Just put in the values!  Good luck.  http://www.onlineconversion.com/temperature.htm
765041
The two properties of the magma that determine the kind of volcano are:\n\n1)Viscosity\n2)Composition\n\nThe viscosity of the magma is a function of the temperature, the degree of crystallization, degree of polymerization and the composition of the melt.\n\nThe composition of the melt is related to the amount of silica it contains and the amount of volatiles dissolved.\n\n\nThis two property are usually coupled (they act together).\nSilica rich magmas are usually colder that mafic ones, contain more volatiles, and hence they have a higher viscosity compared to mafic magmas, so they form strato volcanoes as opposed to shield volcanoes.
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The hot LARVA? I dont know- you cook flies? Now LAVA on the\nother hand, that you get from Joe and his volcano.
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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.
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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.
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here are whole bunch of important info\nhttp://en.wikipedia.org/wiki/Kilauea\n\na vedio of lava flowing\nhttp://www-tc.pbs.org/wnet/savageearth/volcanoes/assets/multimedia/kilauea.mov?mii=1
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The sun is about 15 million degrees C. at its core and about 11000 degrees C. on its surface. Way too hot for anyone to get anywhere close to it.
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Obsidian is lava that cools very quickly.
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It cools as it nears the atmosphere, and finally where we are it's cool enough for us to have evolved to ask the question.\n\nIn fact, the crust is maintained at a rather low temperature  - around 50 degrees F all the time - just 50 to 100 feet down or so. After that the temperature starts increasing. At between 18 and 1800 miles down, it's up at around 212 F (boiling point of water) due to pressure of that 18-1800 miles of rock (the range is wide because at some points in the ocean the mantle is closer to the crust). That's where mantle takes over.\n\nThe basic answer is that we're at least 1000 miles from the mantle. So when you say the mantle is "just" beneath the crust, you're talking about a pretty significant distance.
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cooling and solidification of magma
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Even though I like Oz's answer, it is actually the flow of magma in the Earth's mantle on average about 30 miles below the surface, where molten rock flows from high to low, nearing the earth's outer core where the temprature reaches to near 10000 degrees F.  Another heating element (or actually energy element, that has a side effect of heating) is radioactive decay.  Though most of the Earth's heat energy is released throught the much thinner parts of the crust that makes up the ocean floors.
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He was also obsessed with fire, once baking himself in an oven at 265°F (130°C) for four minutes "without any great discomfort" and to "see what would happen." Later, he arranged to be lowered into Mount Vesuvius in order to view molten lava for himself.
1004160
Pressure release of molten lava, such as a volcanic eruption.
924357
volcanoes are built when tectonic plates push together, the way mountains are formed. except volcanoes have magma inside of them. the gas and magma inside are under extreme pressure, and this pressure pushes its way through small cracks in the rock, eventually escaping in an eruption of gas that brings lava with it. a lot of people have been killed by eruptions, but i cant tell you how many. the lava takes weeks or months to cool down unless it hit the water, which will cool it in a matter of days.
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Volcanoes are a result of the Earth trying to lose its internal heat. If the Earth's interior was cold, there would be no volcanoes. So how does a volcano form hey.\n\nWell, deep inside Earth, between the molten iron core and the thin crust at the surface, there is the mantle, a large layer of rock that is largely solid, but flows like plastic. When, for various reasons, rock from the mantle melts, it sometimes moves to the Earth’s surface through weak spots in the crust, releasing heat, gasses, and rock, what do you get when you put all this together..... you got it,  a volcanic eruption.\n\nVolcanoes erupt because magma is less dense than the solid rocks surrounding it in the mantle of the earth. As it nears the surface, gases expand and boil out of the rock, and this force of explosion propels lava from the vent. \n\nVolcanoes can occur by themselves or in belts and chains. The location of these volcanoes splits them into three groups. Rift volcanoes, subduction volcanoes, and hot spot volcanoes. This has a lot to do with plate tectonics, or moving of the segments of the earth's lithosphere. \n\n· Rift volcanoes occur where the plates are moving away from each other. They fill the separations with lava flows, creating new sea floor and mountain ridges beneath the waves. \n\n· Subduction volcanoes form where the plates collide and slide over each other. They create ridges and peaks. The Ring of Fire is a famous chain of volcanoes that rim the Pacific Ocean. About 1,000 live subduction volcanoes occur in this ring, and in any one-year, approximately 40 will be in some state of eruption. The Ring of Fire is composed of stratovolcanoes, which normally occur in chains, and account for over 95% of the world's active volcanoes.\n\nHot spot volcanoes are the exception to the rule of volcanoes occurring along plate margins. There are constant zones of magma within the earth in some places beneath the plates. The magma pierces through the plate. As time passes and the plates move, new volcanoes appear, and the extinct volcanoes are carried away with the drift of the plates. The common forms of hot spot volcanoes are shield volcanoes, like Mauna Loa of the Hawaiian Islands.\n\nMany factors determine the location, appearance, and amount of activity of each volcano. The location and consistency of magma determine the type of explosion, which determine the type of volcano that is formed. \n\nVolcanoes are both facinating and deadly examples of natures power. They are natural wonders that should be not just appreciated, but studied aswell. \n\nSorry this is long its just I studied volcanoes at uni and just find them fascinating.