Volcanoes and Tectonic Plates

Questions and Answers

What occurs at a constructive margin?

Two plates move towards one another.

Oceanic crust is forced beneath continental crust.

Magma rises to fill gaps between diverging plates. (correct)

Magma is stored in the crater.

Which of the following features is directly involved in the eruption of magma?

Magma chamber

Secondary vent

Fault line

Crater (correct)

What is the main role of the main vent in a volcano?

To reinforce the crustal plates.

To create a secondary vent.

To allow magma to escape to the surface. (correct)

To store molten rock beneath the surface.

What happens to oceanic crust at a destructive margin?

It sinks beneath continental crust at a subduction zone. Signup and view all the answers

How do volcanic eruptions typically affect poorer countries?

They often experience greater damage due to limited resources. Signup and view all the answers

What is created when magma rises from the mantle?

Volcanoes Signup and view all the answers

Which of the following characteristics applies to composite volcanoes?

Made up of alternate layers of ash and lava Signup and view all the answers

Shield volcanoes are primarily formed at destructive plate margins.

False Signup and view all the answers

Name an example of a composite volcano.

Mount Pinatubo Signup and view all the answers

A ______ occurs when tectonic plates move away from one another, leading to the formation of shield volcanoes.

constructive margin Signup and view all the answers

Match the volcano types with their characteristics:

Composite volcano = Found on destructive plate margins Constructive margin = Tectonic plates moving away from each other Destructive margin = Tectonic plates moving towards each other Shield volcano = Formed from basic lava Signup and view all the answers

Study Notes

Volcano Formation

Volcanoes form when magma, molten rock beneath the Earth's crust, erupts to the surface as lava.
Formation generally occurs along plate margins, areas where tectonic plates interact.

Plate Margins

Constructive Margin: Plates move away from each other, allowing magma to rise and fill the gaps between them.
Destructive Margin: Plates move toward each other, causing one to subduct under the other. The oceanic crust sinks and generates magma, leading to volcanic activity.

Impact of Volcanoes

Volcanoes can cause significant damage, especially in poorer countries with limited resources for prediction and preparation.

Distinctive Features of Volcanoes

Magma Chamber: A storage area for molten rock located beneath the ground.
Main Vent: The primary channel through which magma travels to erupt at the surface.
Secondary Vent: An alternate pathway for magma, which may become active if the main vent is blocked.
Crater: The opening at the volcano's summit, where magma is expelled during an eruption.

Types of Volcanoes

Two primary types of volcanoes: composite and shield.
Both types are located along tectonic plate margins, leading to distinct formation processes and characteristics.

Composite Volcanoes

Form at destructive plate margins where two tectonic plates converge.
Oceanic crust is subducted beneath continental crust, resulting in volcanic activity and earthquakes.
Characterized by layered structures of ash and lava.
Example: Mount Pinatubo in the Philippines, known for explosive eruptions.

Shield Volcanoes

Form at constructive plate margins where tectonic plates diverge.
Magma rises to the surface as plates move apart, leading to volcanic formations.
Characterized by broad, gentle slopes and primarily low-viscosity lava flows.
Example: Mauna Loa in Hawaii, formed over a hotspot where intense mantle heat causes magma to reach the surface.
Hotspot volcanic activity contributes to the creation of islands, like the Hawaiian Islands.

Description

Explore the formation of volcanoes through this quiz, focusing on how magma erupts at plate boundaries. Understand the concepts of constructive and destructive margins that play a crucial role in volcanic activity. Test your knowledge on magma, lava, and plate tectonics.