how does density effect volcanoes?
79965
Well.. the density of lava is about 2.6 grams per cubic centimeter,\nBetter yet,\nmagma is swollen by heat, becoming lower in density, and rises through the cooler, higher-density material. A volcano is formed and lava flows across the planet's surface.
704233
Yes. Density is mass/volume. Mass does not change, as weight in pounds does, with a change in gravity. Volume is also the same on the earth and on the moon.
347041
density has to do with the relationship between mass and volume. Water has a density of 1. As long as the mass stays in the same relationship with the volume of water, it has the same density.
286236
A huge eruption, in common terms, can mean an explosive volcano.  And that is caused when magma that is about to exit at the opening begins to cool down and causes the hole to close/block (not leaving enough space for the magma to flow).  This causes hot gas to be trapped until it builds up so much that it explodes.  Such volcanoes include ashes, "volcano bombs", dust, cinder, etc etc\n\nHowever, any type of eruption (be it explosive or just a quiet flow) is caused by movement in the plates. Plates are the result of "continental drift".  When one plate goes under another plate, the plate becomes extremely hot and liquifies.  This "liquid" then builds up, and because it is in excess... it finds a hole though which it can flow.  So the amount is determined by the magnitude of the earthquake and how much of the plate has melted.
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.
1098555
As the temperature rises, the any object dilates, increases its volume. Gases dilates the more for a certain temperature variation. As volume of a certain mass of gas increases, the density decreases. The different temperature and density air masses can move and change their position (= convection), hot and less dense air is rising, while cold and dense air is coming down, forming streams of air (or water). As long as the difference in the temperature / density between the two regions exist, the convection remains. All the winds, seaside breezes, streams in the oceans are streams of air / water formed by convection, where the different temperature and density air  / water moves. Ex. seaside breeze: because the sea water heats up slower than the ground, the warmer air above the ground rises during the day and in its place comes a cooler air from above the sea. In the evening, when the ground starts to cool down, the breeze changes its direction towards the sea. The same for the Golf stream, which is a warm water stream towards the north coming from the warm tropical region, and heating up the cooler region of north - western Europe.
995032
It may gas off or have some activity,but the conditions that created it will probably not happen again.No one should be ramping up fear of the super volcanoes as there is not even a scintilla of enough earth heating to make them blow.
827729
it all depends on what Temperature is acting upon.  If your talking about a solid, no, not really, if it does, it is negligible.  However, Temp. does affect the density of liquids, most liquids become more dense as temp. get colder, and less dense if the temp gets higher.  If you are talking about gasses, then the temp will affect both volume and density. think of a balloon. If you put a balloon outside in the winter, it will become smaller.  This is because the density of the air inside goes up and the volume goes down.... \nThe formula to determine what happens with a gas is PV=nRT, whereby P=the atmospheric pressure, V=volume, n= the #of moles of a gas R=is the ideal gas constant and T=temp... hope that helps.
934882
Curiously, I could not find a comprehensive listing.  This site might be helpful, however, or at least give you a start.\n\nhttp://dir.yahoo.com/Science/Earth_Sciences/Geology_and_Geophysics/Volcanology/Volcanoes
1070192
Volcanoes can put large amounts of volcanic ash\ninto the atmosphere.  This shades the earth,\nreducing the energy input from sunlight and thus\ncauses cooling.  The eruption of the volcano\nKrakatau in Indonesia in 1883 cooled the earth\nslightly.  The Tambora eruption, also in Indonesia,\nin 1815 produced so much ash that the following\nyear was known as the year without a summer.\nThere were very late frosts in Europe and other\ntemperate regions, crop failures and famine.  Such\neruptions can occur anytime, but fortunately are\nrare.
162268
The density of the fluid and the density of the object.
845867
Eruptions have many effects, both good and bad. A major eruption will blow rock, gases and ash into the air. Sometimes melted glacial water mixed with falling debris can cause mudflows in rivers and streams that are capable of sweeping away entire towns. In the short term (the time that the eruption occurs), this can be devastating. Indeed, many living organisms can die, including humans, plants, animals etc., and there can be some economical damage, including destruction of towns or villages, crops, water supplies and food resources. However, in a long period of time, through the force of erosion, volcanic material (particularly ash) will break down. This can form a very rich kind of soil, good for plant growth. Farmers in places near volcanoes can grow an incredible stockpile of good, fresh food because of the good soil.\nLava eruptions are far less dangerous than explosive ones (but lava flows can still pose as a threat). Though a lava flow is very hot and capable of burning anything in its path, it does not move very fast. These lava flows can vary in size, however, and sometimes a flow may destroy some plant life, as well as human settlements. Villages in Hawaii have been burried by lava flows, and there are articles in newspapers that show pictures of houses burning, or abandoned houses half-buried in cooled lava. But, like the explosive eruptions, when lava cools and breaks down over time, it too can form rich soils.\nAsh, an aspect mentioned before, is a volcano's legacy. The ash from a major eruption can travel around the globe in a matter of days. Ash, when seen under a microscope, consists of tiny, sharp particles. These particles can be extremely harmful to the human lungs, or the lungs of any other animal, for that matter. How would you feel if your throat and insides were scratched by miniature, sharp rocks? Ash can also be the opposite of a good soil maker for farmers. If too much ash covers a field, the field is ruined, for the plants will suffocate in the layers of debris. Sometimes, like it was with Mt. St. Helens, ash can pile up on top of roofs of houses, and any roof can cave in from the weight of it (just like snow). \nSo really, volcanoes make up a huge part of Earth in general, and they can have mixed effects on the environment.
280201
Density = mass/volume
316501
Disadvantages: destruction during eruptions,  magma flowing and ash clouds destoys everything on its way, earthquakes are frequent near active volcanoes.\n\nAdvantages: Volcanoes during eruptions throw out materials containing lots of minerals that turn into very fertile soils. After an eruption the land turns to be excellent for agriculture for many years. For example Greek and Roman civilizations settled on the fertile volcanic soils in the Mediterranean-Aegean region.
82591
As the solid decreases, the molecules pack together tighter.  Therefore the volume they take up becomes smaller.  The mass however remains the same.  Because density is equal to mass divided by volume, the smaller the volume, the bigger the density.
703036
When earthquakes occur, they get seismic(?) sample with their instuments. Based on how long the sound waves take to arrive (in relation to each other) can help them determine the relative density of the core. This is because sound travels faster through denser materials, and slower through more sparse ones.
835536
i am not a seismologist but i think the movement of plates create holes and cracks beneath the crust that may cause the formation of openings where the hot gases and great pressures pass through and for several months or years a violent volcano may explode!