Why volcanoes are in different shapes?

Answer 1

Types of Volcanoes and

the Shapes of Volcanoes

Types of Volcanoes

There are 3 different types of volcanoes:

1. Active - eruptions can be anytime and often.

2. Dormant - has been a while since it has erupted, but could at anytime.

3. Extinct, meaning it hasn't erupted in a very long, long time so it probably won't ever again.

Shapes of Volcanoes

How many different shapes of volcano are there?

The type of magma in the earth creates four different types volcanoes:

• shield volcanoes
• composite volcanoes
• cinder cones
• lava domes

Shield Volcano - flat

If the magma is runny, the gas can escape easily and there will not be an explosion. The magma just comes out of the mountain and flows down the sides. Shield volcanoes are shaped like a bowl or shield in the middle with long gentle slopes made by the lava flows. Examples include the volcanoes in Hawaii and Mount Etna.

Composite Volcano - tall and thin

If the magma is thick and sticky (like honey), the gas cannot escape, so it builds up and up until it explodes sending out huge clouds of burning rock and gas. Composite volcanoes are steep-sided volcanoes composed of many layers of volcanic rocks, usually made from thick sticky lava, ash and rock debris (broken pieces). Composite volcanoes are also known as strato-volcanoes. Examples include Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Shasta and Lassen in California, Mount Hood in Oregon, Mount St. Helens and Mount Rainier in Washington and Mt. Etna in Italy

Cinder cones

Cinder cones are circular or oval cones built from erupting lava that breaks into small pieces as it shoots into the air. As small pieces fall back to the ground, they cool and form cinders around the vent.

Lava domes

Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent.

Answer 2

Most volcanoes occur where two plates meet. When two plates move apart causing a gap, hot molten rock - called lava - rises up between them. This type of volcano occurs on the ocean floor and is mostly invisible. If the amount of magma is large enough, it rises above the surface of the ocean and an island is created.If two plates collide and one plate is forced beneath the other plate, the friction makes the first melt and magma rises up. Only a few volcanoes on earth are formed like this, but their eruptions are the most violent and dangerous ones. Sometimes volcanoes also form in the middle of the plates which are called hotspots. These are places that are connected by channels to the hot mantle of the earth.

Three main types of volcano are given below which are formed in distinct ways: -

Shield volcano

Shield volcanoes are almost completely basalt. When magma is very hot and flowing, gases can escape and eruptions are gentle with considerable amounts of magma reaching the surface to form lava flows. Shield volcanoes have a broad, flattened dome-like shape created by layers of runny lava flowing over its surface and cooling down. Because the lava flows easily, it can move down gradual slopes over large distances from the volcanic vents.

Composite volcano

Alternating layers of rock fragments and lava form these volcanoes. This is why they are called composite volcanoes. They are also known as strato-volcanoes. Composite volcanoes generally erupt in an explosive way. When very viscous magma rises to the surface, it usually clogs the crater pipe, and gas in the crater pipe gets locked up. This cause increase in pressure resulting in an explosive eruption. Although strato-volcanoes are usually large and conical, we have more shapes of them: concave, pyramidal, convex-concave, helmet-shaped, collapse caldera, nested, multiple summits, elongated along a fissure.

Caldera volcano

They form when huge amounts of magma erupts out of sub-surface magma chambers. The removal of magma leaves a void below the surface and the top collapses in to form the caldera. The resulting basin-shaped depression is roughly circular and is usually several kilometers or more in diameter. The lava erupted from caldera volcanoes is very viscous and generally the coolest with temperatures ranging from 650°C to 800°C and is called rhyolitic magma. Although caldera volcanoes are uncommon, they are the most dangerous. Volcanic hazards from this type of eruption include tsunami from caldera collapse, large pyroclastic surges and widespread ash fall.

Other types of volcanoes are mid-ocean ridges, monogenetic fields and flood basalts making in all 6 types.

Answer 3

Depends on magma source feeding them:

• Mid-oceanic ridge volcanos have dry basaltic magma supply, it usually flows freely, but not far as water cools it rapidly. The volcanos of Iceland is example of this above water.
• Subduction zone volcanos have wet granitic magma supply, it usually flows sluggishly and explosively as the water comes out of solution and turns to steam. Mount saint helens is example of this.
• Deep mantle hotspot volcanos have very hot dry basaltic magma supply, it usually flows very easily and quietly covering large areas. The hawaiian islands and Yellowstone park (and nearby area of southern Idaho) are examples of this.

Answer 4

Movement on the earth's surface causes formation of various landforms. Faulting which refers to the breaking of rock masses causes the formation of various landforms.The action of weathering, erosion and deposition are processes also that give shape to various landforms.

Answer 5

Types of Volcanoes and

the Shapes of Volcanoes

Types of Volcanoes

There are 3 different types of volcanoes:

1. Active - eruptions can be anytime and often.

2. Dormant - has been a while since it has erupted, but could at anytime.

3. Extinct, meaning it hasn't erupted in a very long, long time so it probably won't ever again.

Shapes of Volcanoes

How many different shapes of volcano are there?

The type of magma in the earth creates four different types volcanoes:

• shield volcanoes
• composite volcanoes
• cinder cones
• lava domes

Shield Volcano - flat

If the magma is runny, the gas can escape easily and there will not be an explosion. The magma just comes out of the mountain and flows down the sides. Shield volcanoes are shaped like a bowl or shield in the middle with long gentle slopes made by the lava flows. Examples include the volcanoes in Hawaii and Mount Etna.

Composite Volcano - tall and thin

If the magma is thick and sticky (like honey), the gas cannot escape, so it builds up and up until it explodes sending out huge clouds of burning rock and gas. Composite volcanoes are steep-sided volcanoes composed of many layers of volcanic rocks, usually made from thick sticky lava, ash and rock debris (broken pieces). Composite volcanoes are also known as strato-volcanoes. Examples include Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Shasta and Lassen in California, Mount Hood in Oregon, Mount St. Helens and Mount Rainier in Washington and Mt. Etna in Italy

Cinder cones

Cinder cones are circular or oval cones built from erupting lava that breaks into small pieces as it shoots into the air. As small pieces fall back to the ground, they cool and form cinders around the vent.

Lava domes

Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent.

Answer 6

Although there are several different types of volcanoes, volcanoes of the same type can still look very different. This is because even though they are the same type their history and eruptive cycles can vary heavily. Another major factor is that volcanoes of the same type can have varying types of eruptive stages, and therefore these recent types of eruptions can greatly change the outward appearance of a volcano. For examples take Mt. Fuji (Japan) and Mt. St. Helens (Washington, U.S.). Recently Mt. Fuji has been in a relatively inactive state and the most recent eruptions were dome building types. In contrast Mt. St. Helens has been realtively active in recent geological terms and has been in a very explosive cycle of eruptions. This explains the major difference of appearances. Mt. Fuji is an almost perfectly conical shape, while Mt. St. Helens has a very large summit crater from the 1980 explosion and flank collapse.

Answer 7

the blue sea is very blue

Yes but what causes diffferent shapes of volcanoes is two diffent plates moving away from each other

Answer 8

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