What is th lifecycle of a volcano?

Answer 1

When the magma is able to penetrate the plates to the surface, you get a volcano eruption. This happens where two plates collide or where they are thinner.

The magma is then called lava. When the lava gets hard, it forms rock and that's how the mountain around volcanoes forms.

Answer 2

Lifecycle of a volcanoThe formationVolcanoes are usually formed through the movement of tectonic plates and the build-up of pressure from convection currents- heat inside the earth - usually in the form of magma. Some volcanoes can form in places other than tectonic plate boundaries. These are known as hot spots. When the magma bursts through the surface, it cools and hardens. Ash might also settle on top of this volcanic rock. This process continues to build up the sides of the volcano.

Divergent boundaries

Divergent plate boundaries are constructive, which means they create new crust. As the plates move away from each other, fissures (cracks) appear and magma from the centre of the Earth rises to the surface, flows outwards, cools, and hardens. When this happens on oceanic crust it results in a mid-ocean ridge. This crust will eventually be pushed back into the earth at a divergent plate boundary. See Image 2

The most famous mid-ocean ridge is the Mid-Atlantic ridge that cuts through Iceland and extends all the way to the tip of South America. Because this plate boundary is constructive, and new crust is being formed, the country of Iceland is slowly being pushed in opposite directions.

Convergent boundaries

Convergent plate boundaries are destructive, which means they destroy crust. As the two plates push against each other, one plate is forced down, back into the centre of the earth to heat up and become magma. This is known as a subduction zone. The pressure of the plates colliding, along with the pressure created from the rising temperatures as the crust descends, can create a volcano.

Oceanic subduction zones can create an island arc and an oceanic trench. Examples of these are the numerous island arcs outlining the Pacific Plate, known as the 'ring of fire'. See Image 3

On continental crust this process can also create a line of volcanoes. An example of continental and oceanic crust convergences is the Andes Mountains where the Nazca plate is subducted by the South American plate. See Image 4

When two areas of continental crust meet, neither is subducted. This creates mountains. An example of this is the Himalayas, which are produced from the convergence of the Indian and Eurasian plates.

Transform boundaries and hot spots

Volcanoes can also occur at transform plate boundaries or at hot spots. Hot spots are areas not along a plate boundary that still produce volcanoes. This is believed to be because of excessive volcanic activity within the Earth's mantle at this area. An example of hot spot volcanoes are the Hawaiian Islands.

The life - what do volcanoes do?Magma, rocks, gases and steam from the Earth's centre are emitted through volcanoes. Volcanic activity can either be intrusive or extrusive. Intrusive volcanic activity results in magma making its way up to the crust, where it cools down and solidifies into volcanic rocks. Extrusive volcanism occurs when magma bursts through the Earth's crust.

Volcanoes are classified according to their size, shape, type of activity, type of eruption, type and amount of gases and lava emitted, and location in relation to tectonic plate boundaries. Scientists have developed four basic categories of volcanoes: cones, shields, composite and domes. See Image 5

See Animation 2

Scoria or cinder cone volcanoes

Scoria cone volcanoes, also known as cinder cones, generally have straight, steep sides with a large crater. These volcanoes are the most common and also the smallest. Eruptions are generally short, explosive bursts of lava that also contain basalt rock fragments.

Shield volcanoes

Shield volcanoes have gentle, rounded slopes. Eruptions are generally non-explosive and calm. Low viscosity (fluid) lava flows outward, and cools and hardens to create the dome of the volcano. Small amounts of gas are emitted.

Composite or strato volcanoes

Strato volcanoes, also known as composite volcanoes, have gentle lower slopes and steep upper slopes. The main crater is usually small. These volcanoes are the deadliest. Eruptions vary widely in power, types of materials and amount of gas and ash emitted. Eruptions are usually characterised by large, thick columns of ash, gas and pumice pieces.

Lava domes or dome volcanoes

Lava domes, or dome volcanoes, have steep, rounded slopes. These volcanoes very rarely erupt. Instead, they are created over time through the build-up of slowly flowing lava that cools and hardens to create a dome.

The afterlife of a volcanoSee Image 6

It is difficult to tell when a volcano is truly extinct. Many volcanoes may be dormant for hundreds, or even thousands, of years and then erupt with little or no warning. A volcano is classified as extinct if there is no written record of its eruption, and it is unlikely that the volcano will erupt in the future.

Volcanic plugs are formed when a volcano becomes extinct and the main lava vent is filled with solidified lava. Over time, erosion processes wear away the lighter materials that created the volcanic dome. All that remains is a column of volcanic rock that is very sturdy and hard to wear away. Examples of volcanic plugs include the Devil's Tower in Wyoming, USA and Mount Warning along the New South Wales and Queensland border.

Lava tubes are formed when the top layers of flowing lava cool down and harden. This forms an insulating crust over the rest of the flowing lava. When the volcano stops erupting, the flowing lava will empty out of the tube, leaving tunnels that can extend for great distances. Australia is home to the world's longest lava tube, which is over 160 kilometres long, formed from the extinct volcano Undara.

Answer 3

well a life style for a volcano is were the lava inside gradually starts to heat up and bubble, sooner rather then later the volcano will got hotter and hotter and eat up the lava witch means the larva raises and eventually over flows and err-ups. the stone inside the volcano heat up and get smashed out of it to but some stones are cooled quicker than other some take a while some take various seconds. The stones are all different some are crystals and some are much more less common stones.

Answer 4

how does a volcano function? how does a volcano function? how does a volcano function?

Answer 5

a volcano works becos lots of heat comes up&then it pushes all the magnum up

Answer 6

active (alive)

dormant (sleeping)

extinct (dead)

Answer 7

when the magma in the chamber gets too hot and shoots out, or when the earths plates move