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Types of Volcanoes

Understanding the different types of volcanoes and their characteristics provides insight into Earth’s geology, aids in hazard prediction and risk management, and helps us to appreciate the dynamic nature of the planet we inhabit.

How Many Types of Volcanoes Are There?

How many types of volcanoes there are depends on who you ask. The three main types of volcanoes are cinder cones, composite volcanoes (stratovolcanoes) and shield volcanoes. Lava domes are a common fourth type of volcano. However, there are other kinds of volcanoes, plus they are compound or complex volcanoes that have features of multiple types. For example, Trident Volcano in Alaska is a complex volcano that include stratovolcanoes and lava domes.

Main Types of Volcanoes

The types of volcanoes vary according to their size and how they erupt. Cinder cones often erupt only once, composite volcanoes erupt infrequently, and shield volcanoes erupt the most often. Cinder cones erupt rocks and gas, without flowing lava. Composite volcanoes erupt thick lava and rocks, while shield volcanoes erupt fluid lava .

Cinder Cones (Scoria Cones)

Cinder cones are the simplest and most common type of volcano. They form as a single eruption vent expels volcanic debris, including ash, cinders, and volcanic rocks. The accumulation of debris forms the cone shape.

• Description : Smallest type, steep sides built from loose volcanic debris from single eruption vent.
• Examples : Paricutin in Mexico
• Size : Generally less than 400 meters tall.
• Magma Composition : Basaltic to andesitic.
• Eruption Frequency : May erupt only once.

Composite Volcanoes (Stratovolcanoes)

Composite volcanoes or stratovolcanoes have the classic “volcano” shape. They are tall, symmetrical cones. Stratovolcanoes form by the accumulation of different types of volcanic materials, including lava, ash, and rock. Their eruptions can be violent.

• Description : Large, symmetrical, steep-sided mountains formed by layers of lava, ash, and volcanic rocks.
• Examples : Mount Fuji in Japan, Mount St. Helens in the United States
• Size : Up to several kilometers in height.
• Magma Composition : Andesitic to rhyolitic.
• Eruption Frequency : Less frequent, more explosive than cinder cones.

Shield Volcanoes

The largest volcanoes are shield volcanoes. These colossal volcanoes boast gentle sloping sides created by the flow of highly fluid basaltic lava. Their eruptions produce extensive lava flows.

• Description : Large, broad, gentle slopes formed by fluid basaltic lava flows.
• Examples : Mauna Loa, Mauna Kea, and Kilauea in Hawaii; Olympus Mons on Mars
• Size : Several kilometers in height and up to 100 km wide.
• Magma Composition : Basaltic.
• Eruption Frequency : Frequent, less explosive eruptions.

Lava Domes (Volcanic Domes)

Lava domes form by the slow oozing of highly viscous lava. They are smaller formations, with steep sides, and often form within the craters of larger volcanoes.

• Description : Small, steep-sided mounds where viscous lava piles up near the vent.
• Examples : Mount St. Helens Lava Dome
• Size : Usually less than 500 meters tall.
• Magma Composition : Rhyolitic or dacitic.
• Eruption Frequency : Variable, usually within the context of larger eruptions.

Other Types of Volcanoes

Cryptodomes.

• Formed by bulging of the volcanic edifice rather than eruptions.

Supervolcanoes

• Extremely large volcanic systems.
• Examples: Yellowstone Caldera in the USA

Submarine Volcanoes

• Located beneath the ocean.
• Examples: Loihi Seamount in Hawaii

Subglacial Volcanoes

• Found under ice caps.
• Examples: Öræfajökull in Iceland

Mud Volcanoes

• Eject mud, water, and gases.
• Examples: Lusi mud volcano in Indonesia

Cryovolcanoes (Ice Volcanoes)

While there are no ice volcanoes on Earth, they exist elsewhere.

• Erupt volatile materials like water or ammonia.
• Examples: Found on Pluto and some moons in our solar system.

Volcanoes in the Solar System

Earth is not the only planet in the solar system with volcanoes:

• Moon : No current activity, but indications of past eruptions
• Mars : Olympus Mons (shield volcano)
• Venus : Numerous shield volcanoes
• Io (Jupiter’s moon) : Hundreds of active volcanoes
• Enceladus (Saturn’s moon) : Cryovolcanoes

Categories of Volcanoes

• Active : An active volcano either is erupting or has a history of recent activity. Earthquake swarms, ground inflation, and carbon dioxide/sulfur dioxide release are indications of activity. Kilauea is an example of an active volcano.
• Dormant : A dormant volcano shows no signs of recent activity, but has potential for erupting in the future. Yellowstone is a dormant volcano. Even though it is an active geothermal site, it goes around 700,000 years between eruptions.
• Extinct : An extinct volcano no long has a magma supply. Shiprock in New Mexico is an example of the remains of an extinct volcano.

Types of Volcanic Eruptions

The broad types of volcanic eruptions are magmatic, phreatomagmatic, and phreatic, but vulcanologists subdivide eruptions either by names or numbers. The Volcanic Explosivity Index (VEI) ranges from 0 for a Hawaiian-type (shield volcano eruption) to an 8 for a supervolcano eruption.

Magmatic Eruptions

• Involves the eruption of magma, mainly from decompression of gases.

Hawaiian Eruption

• Fluid lava flows, effusive.
• Examples: Mauna Loa in Hawaii.

Strombolian Eruption

• Mildly explosive, lava fountains and gas bursts.
• Examples: Mount Stromboli in Italy.

Vulcanian Eruption

• Explosive eruptions producing ash and volcanic bombs.
• Examples: Sakurajima in Japan.

Peléan Eruption

• Eruption with pyroclastic flows.
• Examples: Mount Pelée in Martinique.

Plinian Eruption

• Extremely explosive, large amounts of ash and gas.
• Examples: Mount Vesuvius in Italy.

Phreatomagmatic Eruption

• Interaction of magma with water, explosive.
• Examples: Taal Volcano in the Philippines.

Phreatic Eruption

• Steam-driven eruptions or rock without magma.
• Examples: Mount Ontake in Japan.
• Francis, Peter (1983). “Giant Volcanic Calderas”. Scientific American . 248 (6): 60–73. doi: 10.1038/scientificamerican0683-60
• Philpotts, Anthony R.; Ague, Jay J. (2009). Principles of Igneous and Metamorphic Petrology (2nd ed.). Cambridge, UK: Cambridge University Press. ISBN 9780521880060.
• Schmincke, Hans-Ulrich (2003). Volcanism . Berlin: Springer. ISBN 9783540436508.
• Schmidt, R. (1981). “Descriptive nomenclature and classification of pyroclastic deposits and fragments: recommendations of the IUGS Subcommission on the Systematics of Igneous Rocks”. Geology . 9: 41–43. doi: 10.1007/BF01822152
• Sigurðsson, Haraldur, ed. (2015). The Encyclopedia of Volcanoes (2nd ed.). Academic Press. ISBN 978-0-12-385938-9.

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7.9: Types of Volcanoes

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What does an active volcano look like?

Climbing up Mount St. Helens and looking into the crater at the steaming dome is an incredible experience. The slope is steep and the landscape is like something from another planet. Nothing's alive up there, except maybe a bird. When you're standing on the top, you can see other Cascades volcanoes: Mts. Adams, Rainier, Hood, Jefferson, and sometimes more.

A volcano is a vent through which molten rock and gas escape from a magma chamber. Volcanoes differ in many features, such as height, shape, and slope steepness. Some volcanoes are tall cones, while others are just cracks in the ground ( Figure below). As you might expect, the shape of a volcano is related to the composition of its magma. The three types of volcanoes are composite, shield, and cinder cones.

Composite Volcanoes

Mt. Fuji is a well-known composite volcano.

Figure above shows Mt. Fuji, a classic example of a composite volcano. Composite volcanoes have broad bases and steep sides. These volcanoes usually have a large crater at the top. The crater was created during the volcano's last eruption.

Composite volcanoes are also called stratovolcanoes. This is because they are formed by alternating layers (strata) of magma and ash ( Figure below). The magma that creates composite volcanoes tends to be thick. The steep sides form because the lava cannot flow too far from the vent. The thick magma may also create explosive eruptions. Ash and pyroclasts erupt into the air. Much of this material falls back down near the vent. This creates the steep sides of stratovolcanoes. The composition of magma that erupts at composite volcanoes is usually felsic (rhyolite) or intermediate (andesite).

A cross section of a composite volcano reveals alternating layers of rock and ash. Frequently there is a large crater at the top from the last eruption.

Composite volcanoes are common along convergent plate boundaries. When a tectonic plate subducts, it melts. This creates the thick magma needed for these eruptions. The Pacific Ring of Fire is dotted by composite volcanoes.

Shield Volcanoes

Mauna Kea volcano in Hawaii.

Shield volcanoes look like a huge ancient warrior’s shield laid down. Pictured above is Mauna Kea Volcano ( Figure above) taken from Mauna Loa Volcano. Both volcanoes are part of the Big Island of Hawaii. A shield volcano has a very wide base. It is much flatter on the top than a composite volcano. The lava that creates shield volcanoes is relatively thin. The thin lava spreads out. This builds a large, flat volcano, layer by layer. The composition of lava at shield volcanoes is mafic. Shield volcanoes are very large. For example, the Mauna Loa Volcano has a diameter of more than 112 kilometers (70 miles). The volcano forms a significant part of the island of Hawaii. The top of nearby Mauna Kea Volcano is more than ten kilometers (6 miles) from its base on the seafloor.

Shield volcanoes often form along divergent plate boundaries. They also form at hotspots, like Hawaii. Shield volcano eruptions are non-explosive.

Cinder Cones

Cinder cones are the smallest and most common type of volcano. Cinder cones have steep sides like composite volcanoes. But they are much smaller, rarely reaching even 300 meters in height. Cinder cones usually have a crater at the summit. Cinder cones are composed of small fragments of rock, called cinders. The cinders are piled on top of one another. The cinders can be mafic, intermediate, or felsic in composition. These volcanoes usually do not produce streams of lava. Cinder cones often form near larger volcanoes. Most composite and shield volcanoes have nearby cinder cones.

Cinder cones usually build up very rapidly. They erupt only for a short time. Many produce only one eruption. For this reason, cinder cones do not reach the sizes of stratovolcanoes or shield volcanoes ( Figure below).

A cinder cone volcano in Lassen National Park.

Further Reading

Supervolcanoes

Volcanic Landforms

Hot Springs and Geysers

• Magma composition determines both eruption type and volcano type.
• Composite volcanoes are common at convergent boundaries. Shield volcanoes are produced at divergent plate boundaries and intraplate.
• Cinder cones are made of small fragments of a variety of compositions usually from a single eruption. They are found with composite and shield volcanoes.
• Why do mafic lavas produce shield-shaped volcanoes? Why do felsic lavas produce cone-shaped volcanoes?
• How did composite and shield volcanoes earn their names?
• What features would you use to identify each of the three volcano types?

Home » Volcanoes

Volcanoes for kids

Volcanoes for kids learning in KS2 at Primary School. Homework help with what volcanoes are and how they are formed. Read about the impact of volcanoes on the environment.

What are volcanoes?

Volcanoes are openings in the Earth’s surface. Shaped like mountains they let out ash, gas and hot magma in sometimes violent eruptions.

How does a volcano form?

A volcano forms when two tectonic plates move apart to form a split in the earth's crust. As the plates move apart they allow the magma to come up to the earth's crust creating eruptions.

Volcanoes also appear where two tectonic plates come together. One of the plates is forced down and as it does it melts forming magma that rises through the cracks in the earth's crust.

Some volcanoes can form in the middle of a tectonic plate. Hot spots are under the earth's crust where the magma pushes through to the surface.

What is the cause of a volcano?

Volcanos erupt when the red-hot rock called magma under the earth's crust rises up and pushes through the earth's crust. Pressure causes magma to burst out. Once the magma is out it's called lava.

Which volcanoes are still active?

Volcanoes that don't erupt anymore are called extinct volcanoes. Volcanoes that erupt regularly are called active volcanoes. Some of these active volcanoes can go thousands of years before erupting again. The volcano may look extinct but in fact, it is just dormant (sleeping).

What is the Ring of Fire?

The Ring of Fire is the edge of the tectonic plate that the Pacific ocean sits on. A lot of activity around the edge of the plate. About 75% of all active volcanoes are along this edge and 90% of all earthquakes  occur here as well.

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How are volcanoes measured?

Volcanic eruptions can be measured using the Volcanic Explosivity Index (VEI). The table below shows the VEI scale of eruptions.

Types of volcanic eruptions

There are many types of volcanic eruptions. The Hawaiian is of the most gentle eruptions. Lava is runny so it is a gentle eruption in the form of a fountain. The Plinian is the most violent eruption. Trapped gases cause massive explosions. Huge amounts of ash are thrown high into the air.

Living near a volcano

It is dangerous to live near an active volcano. Volcanologists monitor volcano activity and can tell when a volcano will erupt. When hundreds of small earthquakes are detected, temperatures increase around the volcano and certain gases are released it is a good sign that the volcano is about to erupt.

People who live near the volcano can then have time to evacuate the area. This reduces the number of lives lost each year, but it's still high being around 1,000 deaths a year.

Negative and positive effects on the environment

The lava flow can create huge devastation to land. Lava can clear large areas of farmland and woodland. The natural landscapes and many homes, villages and towns are sometimes destroyed and changed completely.

The dramatic scenery that the eruptions create can attract tourists and bring money to the area.

Lava and ash provide valuable nutrients which make the soil very fertile for farming. For this reason, many people choose to live near volcanoes. The heat and activity under and around a volcano can be turned into geothermal energy which provides locals with the energy they need for their homes.

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What is a volcano?

A volcano is a very deep hole in the Earth’s top layer that can let out hot gasses, ash and lava. Many volcanoes are also mountains.

Volcanoes have long shafts that go all the way down through the Earth’s first layer, the crust, to magma in between the crust and the mantle (the Earth’s second layer). It’s so hot there that rocks melt into liquid! This is called magma, which travels up through volcanoes and flows out as lava .

Top 10 facts

• Volcanoes are big holes that let out hot gasses , ash and magma from deep inside the Earth.
• Many volcanoes are mountains , made up of layers of lava and ash.
• Many volcanoes have several vents – a main one, and secondary ones that branch off the main vent. The volcano’s main vent goes all the way down to the layer of magma in between the Earth’s crust and mantle.
• The Earth has three layers – the crust at the very top, then the mantle , then the core at the very middle of the planet.
• There are three ways to describe a volcano and explain what it’s doing  – active , erupting , and dormant .
• An extinct volcano is one that hasn’t erupted in at least 10,000 years, and that scientists don’t think will erupt again for a very long time.
• The largest active volcano in the world is Mauna Loa, on the Hawaiian islands.
• When a volcano erupts, magma comes up and out through the vents. Magma is called lava when it’s outside the volcano.
• Depending on how thick the magma is, volcanoes can be different shapes such as shield , composite or dome .
• Ash from volcanoes is very good for growing things. It adds nutrients to the soil.

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Did you know?

• crust (at the top)
• mantle (in the middle)
• core (in the centre)
• There are 1,500 active volcanoes in the world and about 50 volcanoes erupt every year!
• Most volcanoes can be found in countries that have coastlines on the Pacific Ocean – this is called the Ring of Fire.
• Gas, ash and magma can come out of volcanoes.
• When magma flows out of a volcano, it’s called lava .
• Most of the gas that comes out of volcanoes is poisonous.
• Some volcanoes are underwater!
• There aren’t any volcanoes in the UK. The largest volcano in Europe is Mount Etna in Sicily (Italy).
• The word ‘volcano’ comes from ‘ Vulcan ’, the Roman god of fire

Volcano pictures

Have a look through the images in the gallery and see if you can spot the following:

• The parts of a volcano © Anthony Bennett, Internet Geography
• A volcano in Hawaii
• Molten lava
• A smoking crater in New Zealand
• An eruption at Mount Krakatoa, between the islands of Java and Sumatra in Indonesia
• Flowing lava
• Mount Etna in Sicily in Italy
• A lava cloud in Hawaii

There are lots of different types and sizes of volcanoes , from small cracks in the Earth's surface to huge mountains which have been built up by lots of layers of lava and ash.

Magma is liquid rock in between the crust and the mantle, formed when part of the lower crust or upper mantle melts.

When magma travels up through a volcano’s vent, bubbles of gas also appear. All the gas builds up pressure, which causes the magma to explode out of the volcano. When magma is thin, the gas bubbles can rise and pop easily – volcanoes located over thin magma don’t have very large explosions. When magma is thick, the gas bubbles get trapped and the pressure builds up so much that the explosion shoots high up into the air. If magma cools down as it rushes up the vent, it will come out as rock or ash.

Volcanoes can be very dangerous; some of the worst natural dissters in human history have been caused by erupting volcanoes. Lava flowing out of volcanoes can burn and destroy anything in its path, and ash can be so thick in the air that it’s hard to breathe. Earthquakes can happen when a volcano erupts, causing very large waves called tsunamis . If gases and ash get into the atmosphere, it can even change the weather by causing thunderstorms and cool temperatures.

When volcanoes haven't erupted for many years (perhaps thousands!), people begin to live near them in order to farm the land which is very fertile thanks to the volcanic ash. If the volcano does erupt, there can be huge loss of human life in nearby cities. In the biggest explosion in recorded history, the eruption of Tambora in Indonesia in 1815, an estimated 60,000 people lost their lives and the ash cloud affected farming, causing the worst famine of the century.

Volcanologists (scientists who study volcanoes) can sometimes tell if a volcano is going to erupt by keeping track of earthquakes underneath it. The types of gases coming out of the vent can also change close to an eruption. Animals living near a volcano may start to act differently, as if they can sense something is going to happen.

The Earth’s surface is made up of lots of pieces called tectonic plates . These plates can slide against each other, which lets magma from underneath squeeze up through the cracks. When tectonic plates move, it also causes earthquakes. Most volcanoes are located along the edges of tectonic plates, especially around the Pacific Ocean – this is called the Pacific Ring of Fire.

The ancient Romans wrote about a huge volcanic eruption that happened in 79 AD in Pompeii . The ash and rocks that erupted out of Mount Vesuvius buried nearby towns and killed more than 2,000 people. Mount Vesuvius is dormant today.

Other famous volcanic eruptions in history are:

• Mount Tambora (Indonesia) in 1815
• Krakatoa (Indonesia) in 1883
• Mount Pelée (Martinique) in 1902
• Mount St Helens (Washington, USA) in 1980
• Mount Pinatubo (Philippines) in 1991
• Eyjafjallajokul l (Iceland) in 2010

Words to know

• Active volcano – a volcano that erupts regularly
• Crater – the bowl-shaped area at the top of a volcano’s vent
• Dormant volcano – a volcano that has not erupted in a very long time, but could again
• Extinct volcano – a volcano that has not erupted in thousands of years, and doesn’t look like it will erupt again
• Magma chamber – the pool of magma located underneath the volcano’s vent
• Supervolcano – a volcano that has an eruption where the amount of stuff that comes out is more than 1,000 cubic kilometres
• Vent – the main part of a volcano where magma and gasses come through from deep inside the Earth
• Volcanologist – a scientist who studies volcanoes

Related Videos

Just for fun...

• Play Volcano Island : decide when you think a volcano is going to erupt and when people should evacuate. Will you make an accurate prediction?
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Children's books about volcanoes

See for yourself

• Visit the Natural History Museum  in London: their brand-new gallery about volcanoes and earthquakes features an earthquake simulator where you can feel the groud shake underneath your feet, as well as a heat suit worn by volcanologists.
• Watch an animation of a volcano erupting from the safety of your own home!
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• Look through some awe-inspiring volcano pictures

Find out more

• CBBC: volcanoes
• See a detailed diagram of what the inside of a volcano looks like
• Download some volcano diagrams
• Look at a volcano facts infographic
• BBC Bitesize: volcanoes
• Watch a video about the Yellowstone supervolcano , one of our planet's restless giants
• Find out how the shape of a volcano reflects its "personality"
• Find out more about plate tectonics  with your very own Plate Tectonics Passport
• Explosive volcano facts from National Geographic Kids
• Animated guide to volcanoes
• Slideshows and interactive guides to all aspects of volcanoes
• Download a factsheet about volcanoes and try an online interactive resource to help you understand plate tectonics
• An interactive map which tracks every recorded volcanic eruption, earthquake and major sulfur dioxide emission since 1960
• See how deadly volcanic eruptions have been in the past with an infographic

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Types of volcanoes Lesson Pack

Subject: Geography

Age range: 16 - 18

Resource type: Lesson (complete)

Last updated

17 January 2024

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Explore the Wonders of Volcanoes with Our Comprehensive Lesson Pack!

Dive into the fascinating world of volcanic activity with our Types of Volcano Lesson Pack! This engaging resource is designed to captivate students’ interest and enhance their understanding of the diverse volcanic landscapes.

What’s Included:

• 36 - slide PPT Presentation: Take your students on a visual journey through the various types of volcanoes, their formations, and the incredible forces that shape our planet. The detailed slides provide rich content and vivid imagery to make learning both informative and enjoyable.
• Accompanying Worksheet: Reinforce classroom learning with our thoughtfully crafted worksheet. This hands-on activity will challenge students to apply their knowledge, ensuring a well-rounded understanding of the material.

Key Benefits:

• Comprehensive Coverage: The lesson pack covers various types of volcanoes, including composite, shield volcanoes, and more.
• Engaging Visuals: The visually appealing slides make complex concepts accessible and promote active learning.
• Classroom Ready: Save time on lesson planning with our ready-to-use materials designed for seamless integration into your curriculum.
• Knowledge Consolidation: The worksheet ensures students solidify their understanding through practical application.

Elevate your volcano lessons and spark curiosity in your students’ minds. Don’t miss out on this valuable resource-grab your Types of Volcano Lesson Pack now!

Ignite the passion for learning about the Earth’s dynamic forces!

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17th August 2019

Volcanoes are holes in the Earth’s crust where extremely hot pieces of rock, gases and other things rise from the Earth’s core. This usually happens in the form of an eruption. Not all eruptions are the same: some eruptions are extremely explosive, like the one in the picture shown below. Others are actually quite calm, where hot lava slowly flows out of the volcano.

An explosive volcano eruption | Wikipedia

How are volcanoes formed?

Volcanoes are usually formed when tectonic plates (large parts of the Earth’s top layer) collide with each other. When they do collide, one plate plunges underneath the other, creating what is called a subduction zone. As the edge of one plate goes down, the temperature and pressure dramatically increases. This releases water from the rocks, which slightly changes the melting point of the rock, creates magma that makes it’s way to the surface.

How many volcanoes are there?

There are 1,500 active volcanoes in the world at the moment. There are many more inactive volcanoes which no longer erupt. When large volcanoes erupt in the middle of the ocean, the extremely hot rock turns into a solid and can create an island.

What damage do they do?

When they erupt, the extremely hot rock can slowly flow towards villages or towns, destroying everything in their path. The gas released from volcanoes can cause problems at airports near the eruption, where flights are cancelled due to the gases produced.

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9.6: Basics-Volcanoes

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INTRODUCTION

The Pacific Northwest is volcanically active. Nearly every type of volcano exists or has existed in the Pacific Northwest, and every type of volcanic eruption has occurred. The Cascade volcanic arc has been catastrophically active during recent human memory. In the last 10,000 years volcanic eruptions have also occurred in such places as eastern Idaho and central Oregon. In some landscape regions of the Northwest, the entire upper crust is almost entirely volcanic rock.

To understand volcanoes, you have to start with magma, the molten rock that comes up from the interior of the earth to form volcanoes. The composition, gas content, and crystal content of the magma determines the type of eruption that occurs, the kind of volcanic rock that forms, and the type of volcano that forms.

SHIELD VOLCANOES

Lava flow after lava flow of low-viscosity, mafic lava builds up a basaltic shield volcano. Shield volcanoes are the largest type of volcano on earth, as exemplified by Mauna Loa on the Island of Hawaii. Shield volcanoes in the Pacific Northwest include: Medicine Lake Volcano in northern California; Newberry Volcano (Paulina Peak) in Oregon; and Simco Volcano in south Central Washington, on the Yakima Indian Reservation near the town of Goldendale.

COMPOSITE CONES

Eruptions of intermediate lava as andesite flows, explosive eruptions of tephra, and intrusion within earlier flows to form dikes and sills, add up to form composite cones. Composite cones are the characteristic volcanoes of volcanic arcs along subduction zones. Composite cones of the Cascadia volcanic arc in the Pacific Northwest include Lassen Peak and Mt. Shasta in northern California, Mt. McGloughlin, Mt. Mazama (Crater Lake), Mt. Thielsen, the Three Sisters, Mt. Bachelor, Mt. Washington, Mt. Jefferson and Mt. Hood in Oregon, and Mt. Adams, Mt. St. Helens, Mt. Rainier, Glacier Peak, and Mt. Baker in Washington. Most of these volcanoes are over 10,000 feet above sea level in elevation. Along with abundant andesite and tephra, composite cones may also erupt lesser amounts of basalt, dacite and rhyolite. That is why they are called composite cones–they are a composite of many types of volcanic rock.

CINDER CONES

Fountain eruptions of volcanic ash, lapilli, blocks, and bombs, usually of mafic composition, pile up in a cone-shaped form to become a cinder cone. Cinder cones are usually less than 1,000 feet tall. Many composite cones and shield volcanoes have cinder cones on their flanks or close by. Cinder cones are small bumps compared to the much larger shield volcanoes or composite cones.

Lava domes are steep-sided domes formed by the pile-up of viscous, felsic magma. It is not uncommon for a composite cone to erupt explosively, forming a crater, and then to erupt high-viscosity lava into the crater, forming a lava dome. The lava that forms the dome may be from the same magma that erupted explosively but, after venting most of its gas in the explosive eruption, it has lost its explosiveness and erupts as flows.

SPATTER CONES

Spatter cones are small volcanic landforms that from when lava spatters up in a small fountain and piles up in blobs of semi-molten material that accumulate into a solid, roughly cone-shaped form a few feet or a few tens of feet tall. A lava flow coming down the flank of a shield volcano or composite cone may spawn a subsidiary spatter cone by bursting out of a solidified crust.

FLOOD BASALTS

Flood basalts usually originate from fissure eruptions, cracks in the surface of the earth that rapidly disgorge huge volumes of lava. Flood basalts are high-volume, widespread flows of mafic magma that solidify into basalt flows that in some cases cover thousands of square miles. The Columbia River Basalts comprise one of the world’s great flood basalt provinces. Some of the Columbia River basalt flows originated near the border of Idaho, covered much of eastern Washington and north central Oregon, and flowed down through the Columbia River gorge beyond the Cascade Range to cover parts of the Portland area and reach the Pacific Ocean, all in gigantic individual flows.

ASH FLOW TUFFS

Ash flow tuffs are large-volume tuffs that originate from huge, explosive eruptions of felsic magma. They are sometimes referred to as ignimbrites. Besides volcanic ash, ash flow tuffs may contain pieces of pumice, pieces of broken rock that were caught up in the eruption, and crystals that had already solidified in the magma before it erupted. All of these materials become welded together in the solidified ash flow tuff. Some ash flow tuffs cover hundreds or, in rare cases, thousands of square miles. The yellow rock that gives Yellowstone National Park its name is an ash flow tuff. The explosive eruptions that form ash flow tuffs usually create a caldera, as the volcano collapses on itself after venting tephra across the landscape.

PILLOW BASALTS

Pillow basalts form when mafic lava erupts underwater. The lava freezes on the outside against the cold water, but keeps flowing on the inside, bulging out into pillow-like shapes which break off from the main flow. These pillows can accumulate into a large volume of pillow basalts. Pillow basalts serve as an indicator that lava was erupted into a body of water. Much of the world’s oceanic crust consists of basalt, most of which erupted onto the seafloor to form pillow basalts. Pillow basalt can also form when mafic lava erupts on land and flows into a lake or into the ocean. In some places, there are layers of pillow basalt in the Columbia River Basalts, showing that the basalt flowed into lakes, forming pillows as it entered the water.

Tephra is also known as pyroclastic material—volcanic material that erupted explosively and flew through the air for some distance before landing on the ground. Tephra results from pyroclastic eruptions, which means explosive volcanic eruptions that hurl material into the air. There are several types of pyroclastic material, or tephra:

Volcanic Blocks

Blocks are large (>5 cm) pieces of tephra that were solid during the eruption. They tend to have blocky or jagged shapes.

Volcanic Bombs

Volcanic bombs are large (>5 cm) pieces of tephra that landed while still molten or semi-molten. They tend to have shapes that were streamlined while passing through the air, or else have a sort of splattered shape from hitting the ground while soft.

Lapilli are pieces of tephra between 0.5 and 5 cm across.

Volcanic Ash

Volcanic ash is fine-grained (<0.5 cm) tephra. It mainly consists of fine pieces of volcanic glass, which form by solidification and splintering of small pieces of the magma during the eruption. It may also contain pieces of crystals, from minerals that had already solidified in the magma before it erupted.

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Contributors and Attributions

Original content from Kimberly Schulte (Columbia Basin College) and supplemented by Lumen Learning . The content on this page is copyrighted under a Creative Commons Attribution 4.0 International license.

©Copyright Mandy Barrow 2013 primaryhomeworkhelp.com

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Providing printables, encouragement, tips and resources to help busy mums balance homeschooling, homemaking and frugal living.

Volcano Unit

Learn all about volcanoes, how they are formed, why they erupt and more with this fun Volcano Unit .

Check out the list of materials that we use with these printables.

With this huge volcano unit, children will learn all about volcanoes. With over 100 pages, there are a variety of different types of activities, worksheets, information pages, research pages, photo images, black and white pages and more.

Information Pages

The information pages include:

• What is a Volcano?
• Composition of the Earth
• Tectonic Plates
• How are volcanoes formed?
• Parts of a Volcano poster
• Parts of a volcano vocabulary
• Parasitic cone
• Fissure vents
• Why does magma rise?
• Why do volcanoes erupt?
• Types of volcanoes
• Cinder Cones
• Cinder Cone volcanoes images
• Shield Volcanoes
• Shield Volcanoes images
• Composite Volcanoes
• Composite Volcanes images
• Stages of a Volcano
• Pyroclastic Material
• Ring of Fire
• Volcano safety tips

Activity Pages

The written activities which include notebooking pages, worksheets and research activities include:

• Label the composition of the Earth diagram
• Describe the different parts that make up the composition of the Earth
• Tectonic plates notebooking page
• Tectonic plates research page – complete the type of plate (major or minor), the size of the plate and one fact about the plate
• Label the parts of a volcano
• Parts of a volcano – match the word to its meaning
• Volcano worksheet – What is a volcano?; How are volcanoes formed?; What is a parasitic cone?; What are fissure vents?
• Volcano worksheet – Why does magma rise?; Why do volcanoes erupt? What are the three types of volcanoes?
• Label the Cinder Cone
• Paricutin ~ Mexico ~ Notebooking Page
• Cerro Negro ~ Nicaragua ~ Notebooking Page
• Wizard Island ~ Oregon ~ Notebooking Page
• Sunset Crater ~ Arizona ~ Notebooking Page
• Label the Shield Volcano
• Mauna Kea ~ Hawaii Notebooking Page
• Mauna Loa ~ Hawaii Notebooking Page
• Fernandina ~ Galapagos ~ Notebooking Page
• Erta Ale ~ Ethiopia ~ Notebooking Page
• Label the composite volcano
• Mt. Fuji ~ Japan ~ Notebooking Page
• Augustine ~ Alaska ~ Notebooking Page
• Mayon Volcano ~ Philippines ~ Notebooking Page
• Mount Hood ~ Oregon ~ Notebooking Page
• Types of Volcano Worksheet – Describe, illustrate and list examples of each of the three types of volcanoes
• Stages of a Volcano worksheet
• Types of Pyroclastic Material worksheet ~ size, describe and illustrate the three types – ash, lapilli, lava bombs and blocks
• Ring of Fire Worksheet ~ location, volcanoes, earthquakes and thoughts
• Draw the ring of fire on the world map and describe the location
• Volcano safety notebooking page
• Design a volcano worksheet page
• Notable volcano eruptions that students can research, study and then report on

This pack includes colour pages, black and white versions of nearly all the pages, (except the ones that contain photo images) as well as answer pages for a majority of the pages.

More Science Resources

• Water Cycle Printables 
• Cloud Formation Cards
• All About Clouds Flip Book
• Snowflake Life Cycle
• Weather Unit – Grades 1 – 3
• Rainy Day Experiment
• Cloudy with a Chance of Meatballs Printables
• All About Snow Study
• Parts of a Map Flip Book
• Biome Flip Books

To grab your copy of this Volcano Printable Pack, click on the link below:

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