How Does A Volcano Form?


20 Answers

Ellie Hoe Profile
Ellie Hoe answered

Volcanoes are formed when magma (molten rocks under the surface of the earth) accumulates in the mountains on the earth's surface. The magma is formed deep inside the earth in Mantle which is the inner crust of the earth. When we hear that volcano has shoot out, it means that magma in the earth's surface has come out of the surface and has burst out of the volcano. High temperatures and increased gas pressures keep on helping magma to form either in the upper crust of mantle or in the base of the crust. The solid mantle or rock should be melted across the depths of 80-100 km below the surface of the earth. When this molten rock gets over heated, it rises because of more gasses and increased pressure and results in eruption of volcano.
Anonymous Profile
Anonymous answered
Volcanoes usually occur when tectonic plates either pull apart or are pushed together allowing the hot molten rock, ash, and gases to escape from the earths crust.....
Zain Aamir Profile
Zain Aamir answered
In February, 1943, in the middle of a cornfield in Mexico, people saw a
rare and amazing thing taking place. A volcano was being born! In three months it had formed a cone about 300 meters high. Two towns were destroyed and a wide area damaged by the felling ash and cinders.

The temperature Under the surface of the earth becomes higher and higher the deeper you go down. At a depth of about 20 miles, it is hot enough to melt most rocks.
When rock melts; it expands and needs more space. In certain areas of the world, mountains are being uplifted. The pressure becomes less under these rising mountain ranges, and a reservoir of melted rock (called "magma") may form under them. This material rises along cracks formed by the uplift. When the pressure in the reservoir is greater than the roof of rock over it, it bursts forth as a volcano.

In eruption, hot gaseous liquid, or solid material is blown out. The material piles up around the opening, and a cone-shaped mound is formed. The "crater" is the depression at the top of the cone where the opening reaches the surface. The cone is the result of a volcano.
The material coming out of a volcano is mainly gaseous, but large quantities of "lava" and solid particles that look like cinders and ash are also thrown out.Actually, lava is magma that has been thrown up by the volcano. When the magma comes near the surface, the temperature and the pressure drop, and a physical and chemical change takes place that changes the magma to lava.
Anonymous Profile
Anonymous answered
It forms by hot material from below rising and leaking into the crust.
Crust- layer of the earth that volcanoes start to happen and is the top layer of the earth.
Volcano- a hole in Earth's surface through which magma or lava, hot gases, ash, and rock fragments escape from deep inside the planet.
kirsty scott Profile
kirsty scott answered
I think that convection currents in the mantle cause the Tectonic plates to move and when they collide the denser plate is submurged under the other plate the magma then has a way to get to the surface. It then breaks through the crust. The mountain look of a volcanoe is built up of ash deposits and lava. I think that is it, it might be wrong.
Romeo Sam Profile
Romeo Sam answered
Volcanic Eruptions
Volcanos are openings in the earth's crust through which molten lava, ash, and gases are ejected. They have caused some of the worst disasters in history, including wiping out entire cities and killing thousands of people. They impressed the Romans so much that their god of fire was represented by a volcano. In fact, that's where the word comes from. It comes from Vulcan, the Roman fire god. They believed that Vucan lived on an island of the Italian coast. The island was volcanic. They called the island Vulcano.
Scientists have divided volcanic eruptions in to four basic groups based on the violence of the eruption and the type of material that erupts. The four groups are Hawaiian, Strombolian, Vulcanian, and Peleean. Hawaiian eruptions are named after the volcanoes in Hawaii and are the least violent type. They produce highly fluid lava that flows quietly from several vents. This gradually builds up a shield volcano.Strombolian eruptions are named after Stromboli. These result from the constant release of gas from the magma. As the gas escapes, it produces tephra that piles up, turning into a cinder cone. Volcanic eruptions get their name from the Roman island Vulcano. Strombolian eruptions happen when sticky magma plugs the central vent. This makes the magmatic gas build up pressure until it blasts. The magma is turned into volcanic dust and bombs. The most violent kind of er
uptions are the Peleean. Their name comes from the eruption of Mount Pelee in 1902 on Martinique, which killed almost 38,000 people. A Peleean eruption occurs when the magmatic gas build up tremendous pressure. This causes violent explosions with glowing clouds of hot ash and dust. Most of the volcano gets torn apart too.It is very hard to predict when a volcanic eruption will occur and most cannot be predicted. When volcanoes erupt, little to nothing can be done to save property, but ma
ny lives can be saved if the area if evacuated soon enough.It is a constant priority for scientists to figure out how to predict them, and they have already made a little progress. Scientists use several devices to figure out when a volcano will erupt. One such instrument is called a tilt-meter, they use it to measure the expansion of a volcano. Thermometers are often used to check the temperature in the surrounding area and gas detectors are used to measure the amount of gas. Though these instruments aren't perfect, they do help.Volcanoes also have many benefits. Many volcanic materials have important industrial and chemical uses. Lava rocks can be used in roads, while pumice is used for grinding and polishing metals and other materials. Volcanic ash improves soil fertility and the underground steams volcanoes produce can be used as a source of energy. Besides these everyday uses, scientists can use volcanoes as "windows" to the inside of the earth. By studying them and the materials they erupt, scientists can gain a better understanding of the earth.The first picture is of an erupting volcano, courtesy of The second picture is of an active volcano, courtesy of
Anonymous Profile
Anonymous answered
A volcano begins by the earths crust and magma forming together to make an eruption which then forms into a volcano.
Anonymous Profile
Anonymous answered
Usually on the edges of tectonic plates. There are 7 known plates. When
the plates bump and grind together, they cause earthquakes, and magma
seeps through those cracks and builds up enough pressure, until the
mountain it is under blows it's top. I live close to Yellowstone park,
one of the World's largest volcanoes, also known as a Super Volcano. It
has been discovered that Yellowstone's entire park is indeed a giant
volcanic crater. Through aerial thermal imaging of the park, they
discovered the magma chamber at the bottom of Yellowstone lake. Anyone
who has been to Yellowstone knows that the lake there is huge,
something like 20 miles in each direction or something. It has been
600,000 years since Yellowstone last erupted, and according to
calculations, we are due for an eruption. Volcanoes is what formed much
of this planet, and has been doing so since the beginning of time.
Anonymous Profile
Anonymous answered
Volcano is derived from the word the name of volcanic island "Vulcano". Scientists still do not fully understand the actual forces that form a volcano. Scientific and geological research today has revealed that a volcano always begins as some form of magma, the molten rock in the earth's crust. Most magma lies about 25 to 150 km below the earth's surface where the heat is so great that it melts the rocs around it. The heated magma produces gases and rises towards the earth's surface, because it is lighter than the surrounding rocks. As more and more magma rises up, it forms a magma chamber the reservoir from which volcanic materials erupts.

A volcano only erupts when the gas filled magma in the reservoir is under such great pressure from the weight of the solid rocks around it that it blasts a vent or conduit in a weekend part of the earth's crust. Upon reaching the earth's surface the gas and the magma is released through an upper vent and all volcanic materials are blasted out in volcanic eruption. The outpouring magma becomes hot, liquid lava, which piles up around the vent in successive layers to form a volcano or volcanic mountain.
amber Jhon Profile
amber Jhon answered
There are various reasons because of which volcanoes are formed, however the major reason is that hot materials rises and leaks into the crust. This material is known as magma. It rises from the lower ground and gathers in a chamber which is known as magma chamber.

When magma erupts, it gets the form of lava. Lava always tries to leak into the earth crust. The two major reasons because of which lava is formed include the rise of the bubbles of materials and secondly, crust goes down.In this way because of the hot materials present in the earth crust, volcanoes are formed.
Mark Profile
Mark answered

Volcanoes are formed because the Earth is very hot inside. Many miles under the hard crust of the earth there is a semi-liquid hot rock called Magma . This Magma produces a lot of very hot gas that tries to force its way up to the surface. Once a weak spot in the Earth's crust becomes too weak to hold back this pressure the hot magma and gases escape, forcing up the earth around it in the process. Repeated lava flows quickly cool and form the familiar shape of a volcano.

Alan Profile
Alan answered
There is a constant flow of lava under the earths crust. When a weakness in the crust appears, the lava breaks through and pushes its way through to the surface where it mounds up into a volcano.
d ds Profile
d ds answered
The earth’s interior is made up of various layers or plates and the points at which various plates meet is called plate boundaries. These plats show different types of motions and when two plates move away form each other, the interior is exposed. As the center of the earth’s temperature is really really high, everything inside it is in molten from and it gushes out through the opening. Another reason is that at times the pressure inside the earth’s crust gets so high as it is really hot the lava makes it way to the surface and then breaks open the surface and we see a volcanic eruption. As the lava pushes upwards, it raises the earth’s surface and we see the formation of a volcanic mountain.
Anonymous Profile
Anonymous answered
It is formed by heat and pressure and because magma is less dess it rises after a long time a volcano is formed

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