2.2.1 Volcanoes

Match the following descriptions with the correct factor responsible for the variation in shape, size, and power of different types of volcanoes.

• Factor influencing the appearance and activity due to historical development

• The volcanic processes at work at a particular geographical location

• Factor influencing the appearance and activity due to its elevation

• The height of the volcano above sea level

• Factor influencing the appearance and activity due to geological dynamics

• The age of the volcano

• Factor influencing the appearance and activity due to surrounding flora

• The amount of vegetation around the volcano

Answer explanation

The main factor responsible for the variation in shape, size, and power of different types of volcanoes is the volcanic processes at work at a particular geographical location.

All volcanoes share some features in common, regardless of their size and power.

(a)  

• Yes, all volcanoes have some featur
• No, volcanoes are completely unique
• Only volcanoes in the same region s
• Common features are only found in v

Answer explanation

The correct choice is 'Yes, all volcanoes have some features in common' because regardless of size and power, all volcanoes share common features.

What does the following diagram show about volcanoes?

• The types of rocks found in volcanoes

• The main volcano types based on shape and size

• The temperature variations in different types of volcanoes

• The eruption patterns of different volcanoes

Answer explanation

The diagram shows the main volcano types based on shape and size, not the other options like rocks, temperature, or eruption patterns.

Viscosity refers to (a)   in the context of lava in shield volcanoes.

• The color of the lava
• The resistance to flow
• The temperature of the lava
• The mineral content of the lava

Answer explanation

Viscosity refers to the resistance to flow in the context of lava in shield volcanoes.

Where do shield volcanoes typically form?

• At destructive plate boundaries

• At constructive plate boundaries and hotspots

• Only at hotspots

• Only at constructive plate boundaries

Answer explanation

Shield volcanoes typically form at constructive plate boundaries and hotspots, making the correct answer choice 'At constructive plate boundaries and hotspots'.

What is a characteristic feature of shield volcanoes?

• They have steep slopes

• They have a narrow base

• They have gentle slopes

• They are made entirely of ash

Answer explanation

Shield volcanoes have gentle slopes, which is a characteristic feature distinguishing them from other types of volcanoes.

How does the actual length of the volcano from the crater compare to its height and width in the case of Kilauea in Hawaii?

• It is shorter than both the height and width

• It is longer than the height but shorter than the width

• It is longer than both the height and width

• It is the same as the height and width

Answer explanation

The actual length of the volcano from the crater is longer than both the height and width, making the correct answer choice: 'It is longer than both the height and width'.

Composite volcanoes typically have (a)   lava.

• Low-viscous lava
• High-viscous lava
• No lava
• Water-like lava

Answer explanation

Composite volcanoes typically have high-viscous lava, which is thick and sticky, leading to explosive eruptions due to pressure build-up.

Composite volcanoes are usually found at which type of plate boundaries?

• Constructive plate boundaries

• Destructive plate boundaries

• Transform plate boundaries

• Plate boundaries are not related to volcano types

Answer explanation

Composite volcanoes are usually found at destructive plate boundaries where one plate subducts under another, leading to volcanic activity

Why are composite volcanoes considered explosive?

• Because they are very tall

• Because they have low-viscous lava

• Because the viscous magma traps gas and builds pressure

• Because they erupt frequently

Answer explanation

Composite volcanoes are considered explosive because the viscous magma traps gas and builds pressure, leading to explosive eruptions.