Types of Volcanoes: Active, Dormant, Extinct and More

Types of volcanoes can be understood easily when you imagine Earth as a living, breathing planet. Some volcanoes erupt quietly, some burst out with force, and others stay calm for a very long time. Each type has its own way of forming, erupting, and changing the land around it. This article mainly focuses on different types of volcanoes with a detailed explanation. 

Table of Contents

• What is a Volcano and a Volcanic Eruption
• Different Stages of a Volcano
• Different Types of Volcanoes
• Types of Volcanoes: Based on Explosive Activity

What is a Volcano and a Volcanic Eruption

Imagine Earth having a small “Door” that opens directly into its molten interior, and that’s exactly what a volcano is! It is a vent or opening in the Earth’s crust through which magma, hot gases, and volcanic materials escape from deep inside the planet.

In simple words, a volcano and a volcanic eruption can be defined as,

“ A volcano is an opening on the surface of Earth (or even other planets like the Moon) that allows hot molten material from the inside to come out. When this material erupts, we call it a volcanic eruption.”

You may wonder, beneath the ground lies a huge chamber filled with molten rock called magma, which is under enormous pressure. When that pressure becomes too strong for the surrounding rocks to contain, the magma bursts out to the surface as lava, ash, steam, and broken pieces of rock.

Read More: Volcanoes, Volcano Eruption

Different Stages of a Volcano 

There are 3 types of volcanoes grouped including active, dormant, and extinct. These categories tell us how likely a volcano is to erupt.

• Active Volcano:  An active volcano has erupted recently and may erupt again in the near future.
• Dormant Volcano: A dormant volcano hasn’t erupted for a long time, but it can still erupt someday.
• Extinct Volcano: An extinct volcano last erupted thousands of years ago, and scientists believe it will not erupt again.

Now, you know what Volcanoes, volcanic eruptions and the stages of volcanoes are. Let's discuss how many types of volcanoes there are. 

Different Types of Volcanoes

Volcanoes come in many shapes and sizes, and scientists classify them into four main types, including 

1. Cinder Cones
2. Composite Volcanoes
3. Shield Volcanoes
4. Lava Dome

Let's discuss them one by one. 

• Cinder Cones are the small, circular or oval-shaped volcanoes formed from fragments of lava that have been explosively ejected from a single vent. These fragments, often called scoria or pyroclastic material, fall back and accumulate around the vent, creating a steep-sided cone

Here is one interesting fact about Cinder cones. 

Most cinder cones erupt only once in their lifetime! Some appear as flank vents on larger volcanoes, while others stand alone.

• Composite Volcanoes, which are also known as stratovolcanoes, are tall, steep-sided mountains made of alternating layers of lava, ash, and rock debris. Their unique layered structure is what gives them the name “composite”.

You may wonder after knowing that, Composite volcanoes grow in three main steps, including,

• Cinders and ash pile up first
• Lava flows over the ash, cooling and hardening
• The cycle repeats, building the classic conical shape

These volcanoes are capable of explosive eruptions, making them some of the most dramatic and dangerous volcanoes on Earth.

• Shield volcanoes are broad, gently sloping volcanoes that look a bit like a warrior’s shield lying on the ground. They form from low-viscosity basaltic lava, which flows easily and can travel long distances.

But here one question arises, why are shield volcanoes different from others?

Unlike composite volcanoes, shield volcanoes rarely erupt violently. Their lava is low in silica, making it runny rather than sticky.

• Lava domes are steep-sided mounds created when very thick lava erupts slowly-slowly and piles up near the volcanic vent. Here, because of the lava, which is so viscous, it does not flow far, forming a dome-shaped structure.

Here is one interesting fact about lava domes: Lava domes can grow inside the craters of previous eruptions. While their eruptions are generally slower than composite volcanoes, they can still produce violent explosions if pressure builds too much.

Types of Volcanoes Based On Their Explosive Activity

You might think that all volcanic eruptions look the same. Interestingly, the volcanic eruptions do not all look the same! The type of volcanoes depends on several factors, including magma chemistry, temperature, viscosity, volume, and the presence of water or gases. 

Let’s discuss the main types in detail:

1. Hydrothermal eruption does not involve magma. Instead, they are powered by heat from underground hydrothermal systems, which causes steam and ash to blast out of the volcano.

2. A Phreatic eruption occurs when magma heats groundwater, producing a steam-driven explosion. Like hydrothermal eruptions, they release ash but no lava, making them sudden and sometimes unexpected.
3. In phreatomagmatic eruptions, newly formed magma interacts directly with water, creating violent steam explosions. This type combines the features of both magma-driven and water-driven eruptions.
4. Strombolian and Hawaiian Eruptions:

• Hawaiian eruptions are famous for their lava fountains and gentle lava flows that can travel long distances.
• Strombolian eruptions are more explosive, sending lava fragments into the air in short, powerful bursts.

5. Vulcanian Eruption is short-lived but intense, often shooting ash and volcanic gas up to 20 km high. They are more explosive than Hawaiian or Strombolian eruptions but don’t last very long.
6. Subplinian and Plinian Eruptions:

• Subplinian eruptions reach heights of up to 20 km, producing large columns of ash and gas.
• Plinian eruptions are even more powerful, with eruption columns soaring 20–35 km into the sky, spreading ash over vast distances.

So far, we have seen that volcanoes come in many shapes, sizes, and behaviours, each forming and erupting in its own unique way. From quiet lava flows to explosive ash clouds, every type of volcano helps us understand how dynamic and powerful our planet truly is.