Volcanoes: Eruptive Patterns and Types

Questions and Answers

What types of volcanoes can be classified as Shield Volcanoes, Cinder Cone/Scoria cone volcanoes, and Composite Volcanoes/Stratovolcanoes?

Types of lava flows

Types of eruptions

Types of volcanic rocks

Types of volcanoes (correct)

What is a Shield Volcano?

A type of volcano with a wide base and broad summit area that resembles a warrior's shield.

What is the composition of magma at shield volcanoes?

Mafic magma.

What characterizes Cinder Cone volcanoes?

A volcano with a steep conical hill of debris deposited around a volcanic vent. Signup and view all the answers

What are Composite volcanoes also known as?

Stratovolcanoes. Signup and view all the answers

What is the composition of magma at Composite volcanoes?

Felsic magma. Signup and view all the answers

What is a Lava Flow?

A mass of lava or molten rock flowing downslope from the vent. Signup and view all the answers

What does Andesitic lava flow form?

Andesite rock. Signup and view all the answers

What does Rhyolitic lava flow form?

Rhyolite rock. Signup and view all the answers

What does Basaltic lava flow form?

Basalt rock. Signup and view all the answers

What does Pahoehoe flow mean?

Smooth, unbroken lava. Signup and view all the answers

What does Aa flow translate to?

Stony rough lava. Signup and view all the answers

What are Lava tubes?

Cave-like tunnels that were once conduits for lava. Signup and view all the answers

What are Pyroclastic materials?

Pulverized rocks, volcanic blocks, and gases expelled by explosive volcanic activity. Signup and view all the answers

What is a volcanic block?

A solid piece of rock. Signup and view all the answers

What is a volcanic bomb?

A semi-molten rock expelled from a volcano. Signup and view all the answers

What is a Pyroclastic flow?

A flow of hot clouds of gas, rock particles, and liquid lava droplets. Signup and view all the answers

What is a Pyroclastic surge?

A high-velocity current of hot clouds of gas and rock particles. Signup and view all the answers

What are Tephra flows?

Fragments of volcanic rock and lava blasted into the air. Signup and view all the answers

What is Lahar?

A type of mudflow consisting of water and volcanic ash. Signup and view all the answers

Study Notes

Classification of Volcanoes

Volcanoes can be classified into three primary forms: Shield, Cinder Cone/Scoria Cone, and Composite/Stratovolcanoes.

Shield Volcanoes

Characterized by a wide base and a broad summit, resembling a warrior's shield.
Composed primarily of mafic magma, resulting in less explosive eruptions.

Cinder Cone/Scoria Cone Volcanoes

Form steep conical hills composed of debris ejected from a volcanic vent.
Typically have eruptions that are short-lived and localized.

Composite Volcanoes/Stratovolcanoes

Display steep sides formed by alternating layers of lava flows and pyroclastic materials.
Comprised mainly of felsic magma, leading to more explosive eruptions.

Types of Lava Flow

Lava Flow: Mass of lava flowing downslope; distinct from magma, which exists beneath the crust.
Andesitic Lava Flow: Forms andesite rock; typically more viscous than basalt.
Rhyolitic Lava Flow: Results in the formation of rhyolite rock; usually has a high viscosity.
Basaltic Lava Flow: Creates basalt rock; flows in thin, broad sheets due to low viscosity.

Lava Characteristics

Pahoehoe Flows: Smooth, unbroken lava flows; surfaces resemble twisted ropes.
Aa Flows: Rough, jagged lava surfaces with sharp edges; named for their stony appearance.

Lava Conduits

Lava Tubes: Cave-like structures that transport lava from the vent to the flow's edge.

Pyroclastic Materials

Composed of ejected materials including pulverized rock, ash, and gases from explosive eruptions.
Volcanic Block: Solid rock fragments expelled during an eruption.
Volcanic Bomb: Semi-molten rock ejected from a volcano.

Pyroclastic Flows and Surges

Pyroclastic Flow: Dense mixture of hot gas, rock particles, and lava droplets moving in a laminar flow.
Pyroclastic Surge: Rapid, turbulent flow of gas, rock particles, and lava droplets with high velocity.

Tephra

General term for fragments of volcanic rock and lava ejected into the air, varying in size.
Tephra Flow: Consists of volcanic materials categorized by size (ash: <2 mm, lapilli: 2-64 mm, blocks/bombs: >64 mm).

Lahars

Mudflows consisting of water, volcanic ash, and debris, resembling flowing wet concrete.

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Description

This flashcard quiz focuses on the classification of volcanoes based on their eruptive patterns and forms. You'll learn about shield volcanoes, cinder cone volcanoes, and composite volcanoes, along with key definitions and characteristics. Test your knowledge on volcanic types and their eruptions!