Types of Volcanoes

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Shield volcanoes are the most common type of volcano. They are formed by the eruption of fluid, basaltic magma. Basaltic magma is low in silica and high in iron and magnesium. It is also very fluid, which allows it to flow long distances before it cools and solidifies. Shield volcanoes are typically broad and low, with gently sloping sides. They are found in many parts of the world, including Hawaii, Iceland, and the Galapagos Islands.

Cinder cones are also formed by the eruption of basaltic magma, but they are much smaller than shield volcanoes. Cinder cones are typically less than 100 meters tall and have steep, conical slopes. They are formed when cinders, or small pieces of volcanic rock, are ejected from a volcano and then fall back to the ground around the vent. Cinder cones are common in the western United States, including in the states of Arizona, California, and Nevada.

Composite volcanoes, also known as stratovolcanoes, are the most complex type of volcano. They are formed by the eruption of both basaltic and rhyolitic magma. Rhyolitic magma is high in silica and low in iron and magnesium. It is also much less fluid than basaltic magma, which means that it erupts explosively. Composite volcanoes are typically tall and have steep, symmetrical slopes. They are found in many parts of the world, including the Andes Mountains of South America, the Cascade Range of North America, and the Japanese Alps.

Lava domes are formed when lava is too viscous to flow very far. Instead, it piles up around the vent, forming a dome-shaped structure. Lava domes are typically found on the flanks of composite volcanoes. They can also form on their own, as in the case of the Bishop Tuff dome in California.

Maars are small, crater-shaped volcanoes that are formed when magma comes into contact with groundwater. The resulting explosion blasts a hole in the ground, leaving behind a crater. Maars are typically less than 1 kilometer in diameter. They are found in many parts of the world, including the Eifel region of Germany and the Auvergne region of France.

Fissure eruptions are a type of volcanic eruption that occurs when magma flows out of a long, narrow crack in the Earth’s crust. Fissure eruptions can be very large, and they can cover a wide area with lava. They are often associated with rift zones, which are areas where the Earth’s crust is pulling apart. Fissure eruptions are common in Iceland and East Africa.

Submarine volcanoes are volcanoes that erupt beneath the surface of the ocean. They are much more common than land volcanoes, but they are difficult to study because they are underwater. Submarine volcanoes can form chains, or seamounts, that rise from the ocean floor. They can also form individual volcanoes, or guyots, that have flat tops. Submarine volcanoes are important because they can create new landmasses and affect the Earth’s climate.

Ice volcanoes are volcanoes that erupt beneath the surface of glaciers or ice sheets. They are very rare, but they have been found in Antarctica, Greenland, and Iceland. Ice volcanoes are formed when magma melts the ice above it and then erupts through the ice. They can be very large, and they can reach heights of several hundred meters. Ice volcanoes are important because they can contribute to sea level rise.

Supervolcanoes are the largest type of volcano. They are formed when a huge amount of magma erupts from the Earth’s crust. Supereruptions can release thousands of times more magma than a typical volcanic eruption. They can also cause widespread devastation, including earthquakes, tsunamis, and Climate Change. Supervolcanoes are rare, but they have occurred throughout Earth’s history. The most recent supereruption occurred about 74,000 years ago at Toba in Indonesia.
Shield volcanoes are broad, low volcanoes with gently sloping sides. They are formed by the eruption of fluid lava, which flows long distances before cooling and solidifying.

Cinder cones are small, steep-sided volcanoes that are formed by the eruption of cinders and ash. Cinders are small, solid pieces of lava that are ejected from a volcano during an eruption. Ash is a fine-grained material that is also ejected from a volcano during an eruption.

Composite volcanoes, also known as stratovolcanoes, are tall, conical volcanoes that are formed by the eruption of both lava and pyroclastic material. Pyroclastic material is a mixture of hot gas, ash, and rock fragments that is ejected from a volcano during an eruption.

Lava domes are steep-sided, dome-shaped volcanoes that are formed by the eruption of very viscous lava. Viscous lava is lava that is thick and slow-moving.

Maars are small, crater-shaped volcanoes that are formed by the eruption of carbon dioxide gas. Carbon dioxide gas is a colorless, odorless gas that is heavier than air. When carbon dioxide gas erupts from a volcano, it can cause the ground to collapse, forming a crater.

Fissure eruptions are volcanic eruptions that occur along long, narrow cracks in the Earth’s crust. Fissure eruptions can be very large and can produce a lot of lava.

Submarine volcanoes are volcanoes that erupt beneath the surface of the ocean. Submarine volcanoes can be very large and can produce a lot of lava.

Ice volcanoes are volcanoes that erupt beneath the surface of glaciers or ice sheets. Ice volcanoes can be very large and can produce a lot of lava.

Supervolcanoes are volcanoes that are capable of erupting with a volume of magma that is greater than 1,000 cubic kilometers. Supereruptions are very rare, but they can have a devastating impact on the Earth’s climate.
Question 1

Which type of volcano is characterized by a broad, gently sloping profile?

(A) Shield volcano
(B) Cinder cone
(CC) Composite volcano
(D) Stratovolcano
(E) Lava dome

Question 2

Which type of volcano is characterized by a steep, conical profile?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Lava dome

Question 3

Which type of volcano is composed of alternating layers of lava and ash?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Lava dome

Question 4

Which type of volcano is composed of viscous lava that forms a steep, dome-shaped structure?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Lava dome

Question 5

Which type of volcano is formed when magma erupts through a fissure in the Earth’s crust?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Fissure eruption

Question 6

Which type of volcano is formed underwater?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Submarine volcano

Question 7

Which type of volcano is formed when water and magma interact?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Maar

Question 8

Which type of volcano is the largest and most destructive?

(A) Shield volcano
(B) Cinder cone
(C) Composite volcano
(D) Stratovolcano
(E) Supervolcano

Answers

1. (A)
2. (C)
3. (D)
4. (E)
5. (E)
6. (E)
7. (E)
8. (E)