Volcanoes

Question 1

What are the three main types of volcanoes?

Answer 1

Shield volcanoes, stratovolcanoes, and cinder cone volcanoes. Each type has its own unique characteristics and eruptive behaviors.

Question 2

Whats a shield volcano?

Answer 2

A shield volcano is formed by repeated eruptions of fluid lava that flows easily and spreads out over a wide area. (Shield volcanoes are known for their relatively calm eruptions.)

Question 3

Whats a stratovolcano

Answer 3

A stratovolcano, is a tall and steep-sided volcano formed by alternating layers of lava, ash, and volcanic debris. They are characterized by explosive eruptions and can have a conical shape. Stratovolcanoes are known for their potential to produce pyroclastic flows, lahars, and ashfall. They are often found in subduction zones where tectonic plates collide.

Question 4

Whats a cinder cone volcano

Answer 4

A cinder cone volcano is a type of volcano that is small in size It is formed by explosive eruptions that eject fragments of lava, ash, and volcanic gases into the air. These fragments, known as cinders or scoria, fall back to the ground and accumulate around the vent, building up the cone-shaped structure. Cinder cone volcanoes are typically short-lived.

Question 5

Whats a dome volcano?

Answer 5

It is formed by the slow extrusion of highly viscous(sticky)lava, which piles up and solidifies around the vent. Dome volcanoes are often associated with explosive eruptions and can be found in volcanic areas where the lava is too thick to flow far from the vent.

Question 6

Are cone and strato the same

Answer 6

Yes

Question 7

What are the three types of magma

Answer 7

Basaltic, andestic, and rhyolitic

Question 8

How are andestic and rhyolitic magma sourced

Answer 8

Subduction

Question 9

What is the source of basaltic magma

Answer 9

Stretching of the crust or from a hot spot in the mantle

Question 10

Whats the level of silica in basaltic magma

Answer 10

Low

Question 11

Whats the level of silica in andestic magma

Answer 11

Medium

Question 12

Whats the level of silica in rhyolitic magma

Answer 12

High

Question 13

What does viscousity mean

Answer 13

it describes the resistance of lava to flow. Lava with high viscosity is thick and doesn’t flow easily, while lava with low viscosity is more fluid and flows more easily.

Question 14

Whats the viscosity of basaltic magma

Answer 14

Runny (moves fast)

Question 15

Whats the viscosity of andestic magma

Answer 15

Sticky (average speed)

Question 16

Whats the viscosity of rhyolitic magma

Answer 16

Very sticky ( slow moving)

Question 17

Amount of gas in basaltic magma

Answer 17

Small amount

Question 18

Amount of gas in andestic magma

Answer 18

Larger - moderate/medium levels

Question 19

Amount of gas in rhyolitic magma

Answer 19

Largest amount of all, violent

Question 20

How does the amount of gas in magma affect a volcano

Answer 20

When there is a high concentration of gas in magma, it can lead to explosive eruptions. As the magma rises to the surface, the pressure decreases, causing the dissolved gases to rapidly expand and escape. This sudden release of gas can result in powerful explosions, ejecting ash, rocks, and lava into the air. On the other hand, magma with lower gas content tends to have more effusive eruptions, where the lava flows more smoothly and steadily.

Question 21

Whats a lava flow?

Answer 21

A lava flow refers to the movement of molten rock, or lava, from a volcano. It occurs when the lava erupts from the volcano and travels down the slope, spreading out and covering the surrounding area. Lava flows can vary in speed and size.

Question 22

Whats a pyroclastic flow?

Answer 22

A pyroclastic flow is a fast-moving mixture of hot gas, ash, and volcanic particles that cascades down the slopes of a volcano during an explosive eruption. It can reach speeds of hundreds of kilometers per hour and can be extremely destructive, incinerating everything in its path. Pyroclastic flows are known for their high temperature and density.

Question 23

Whats a lahar?

Answer 23

A lahar is like a muddy avalanche that happens during or after a volcanic eruption. It occurs when volcanic ash, rocks, and debris mix with water, such as from heavy rainfall or melted snow, creating a fast-moving flow. Lahars can travel down the slopes of a volcano and through valleys, causing significant damage to structures and landscapes in their path.

Question 24

What are the two types of volcanoes?

Answer 24

Hot spots and subduction. examples, TVZ= subduction, auckland area = hot spot

Question 25

Whats a dormant volcano?

Answer 25

volcanoes that have not erupted in a long time but are expected to erupt again in the future.

Question 26

Whats an extinct volcano?

Answer 26

those which have not erupted in human history

Question 27

Active volcano

Answer 27

Likely to erupt again