Comprehensive Facts About Volcanoes. 3 Main Types

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How Much Information Do You Have About Volcanoes?

Volcano is an extremely exciting topic for kids to read about. There are always questions in the kids’ minds about volcanoes. What is the definition of Volcanoes? What do they look like? How are they formed? Where are they located? What happens when a volcano erupts?

There is a history of volcanoes. There are also different types of volcanoes. As well, there are different stages of volcanoes. There is a difference between the categories of volcanoes active, dormant and extinct. 

Volcanology is the branch of geology that focuses on volcanoes.. Volcanoes usually have some effects after they erupt. Not all these effects are negative, there are positive effects as well. 

What is a Volcano?

A volcano is an opening in Earth’s crust. It is a hole in the Earth from which molten rock and gas erupt. Volcanic eruptions may be very destructive. But they also create new landforms. There are more than 1,500 potentially active volcanoes in the world today.

How Are Volcanoes Formed?

Volcanoes are formed when magma at the centre of the Earth pushes its way upwards through the Earth through a long shaft. When the magma travels through the Earth’s crust it emerges as lava. Once this lava has erupted onto the Earth’s surface, it cools and hardens into a pile of rock. 

Sometimes volcanoes build up pressure as the magma emerging from inside the Earth pushes upwards, and this can cause volcanoes to explode with great force. These volcanoes are called composite volcanoes.

What Are The Different Stages of Volcanoes?

Scientists have created three main categories for volcanoes: active, dormant and extinct. An active volcano is one which has recently erupted and there is a possibility that it may erupt soon. A dormant volcano is one which has not erupted in a long time but there is a possibility it can erupt in the future. An extinct volcano is one which has erupted thousands of years ago and there’s no possibility of eruption.

What Are The Different Types of Volcanoes?

Volcanoes are grouped into four types: cinder cones, composite volcanoes, shield volcanoes and lava volcanoes.

Cinder Cones

Cinder cones are circular or oval cones made up of small fragments of lava from a single vent that have been blown into the air, cooled and fallen around the vent.

Cinder cone volcanoes are the smallest type of volcano. They are rarely more than 1,000 feet tall. Cinder cone volcanoes often form on the surface of larger volcanoes, creating a very active surface. They usually do not erupt for very long.

The summit of Cinder Cone has a crater with a double rim probably created by two different phases of one eruptive period. The cone also has a widespread ash deposit identifiable for 8 to 10 miles (13 to 16 km) from the cone. Blocks of red, cemented scoria within the Painted Dunes lava flows are pieces of this earlier cone, which were carried away by the flowing lava.

Cinder cones are a ‘friendly face’ of volcanic activity – their fire-fountain eruptions are beautiful and dramatic, and because their lava tends to fall straight down and cool quickly, they don’t endanger thousands of lives or lay waste to vast areas. It can be relatively safe to view these eruptions close-up.

Cinder Cone lies in Northern California, within the United States. Located 1.5 miles (2.4 km) southwest of Butte Lake and 2.2 miles (3.5 km) southeast of Prospect Peak (which dwarfs Cinder Cone), it is also sometimes referred to as Black Butte or Cinder Butte. 

Composite Volcanoes 

Composite volcanoes are steep-sided volcanoes composed of many layers of volcanic rocks, usually made from lava, ash and rock debris. Mt. Rainier and Mount St. Helens are examples of this type of volcano.

Composite volcanoes take hundreds of years to build up their steep sides through periods of eruptions and sleep. Volcanoes first form when a vent in the Earth’s crust reaches down into pockets of molten rock called magma. 

Magma escapes from the vent and builds up a mound around it as it cools and hardens. In stratovolcanoes, this mound typically grows to be a giant mountain as is seen in Mt. Fuji, in Japan. 

Composite volcanoes have steep slopes, forming a basically symmetrical shape. The last eruption of the volcano may have even created a bowl, a caldera, at its peak, making it appear as if the top of the mountain was sliced off, or it may have collapsed from its own weight. 

Composite volcanoes vary in size, based upon how long they have been active, how many eruptions they’ve undergone and how much they’ve eroded with time. Mount Shasta, in the Cascade mountain range in Northern California, for example, stands 14,163 feet above sea level

Composite volcanoes, which are also called stratovolcanoes, stand tall on different continents and rise from the waters of some of the world’s oceans. One of the most common places to find a composite volcano is in the Ring of Fire, which is a half circle of volcanoes that have formed a border around the upper part of the Pacific Ocean.

The U.S. is home to some famous composite volcanoes. Mount Hood, which is the tallest mountain in Oregon, is a composite volcano. It’s an active volcano but has only had two major periods of eruption in the last 1,500 years.

Shield Volcanoes

Shield volcanoes are volcanoes shaped like a bowl or shield in the middle with long gentle slopes made by basaltic lava flows. Basalt lava flows from these volcanoes are called flood basalt.

Shield volcanoes might not be tall, but they are wide. The width of a shield volcano is often about 20 times its height. This flattened shape is due, in part, to the watery lava, or hot molten rock, that flows out of them.

Because the lava is not very thick, it tends to run out in all different directions. Think of a shield volcano’s lava as milk spilling from a glass, and lava from other volcanoes as slow-flowing molasses. The fluid lava can travel a longer distance before it cools and hardens, which keeps it from piling into tall mounds.

Shield volcanoes form primarily in the oceans although they can form anywhere on Earth. Scientists estimate there are over one million seamounts on the ocean floors. Scientists estimate there are about 4,000 submarine volcanoes for every million square miles of ocean floor in the Pacific Ocean. 

Oregon and Washington have a number of shield volcanoes that have formed on the continent. Newberry Volcano is a large shield volcano that is unusual because it has erupted not only basalt lava but andesite and rhyolite lavas.

The largest is Mauna Loa on the Big Island of Hawaii. Shield volcanoes can be so large they are sometimes considered a mountain range, such as the Ilgachuz Range and the Rainbow Range, both of which are in Canada.

Shield volcanoes are known to form on other planets. The largest known mountain in the solar system, Olympus Mons on Mars, is a shield volcano. Shield volcanoes on Mars are higher and much more massive than those on Earth.

Lava Dome Volcanoes

Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent. Lava domes are formed when erupting lava is too thick to flow and makes a steep-sided mound as the lava piles up near the volcanic vent.

Lava domes are not all exactly the same. The shape and size often depend on how quickly the lava flows when it is coming onto the surface. Some lava domes are circular in shape and flat, while others are taller and make more of a point at the top. Most lava domes have very steep sides and some can be over half a mile in height. 

Some of the world’s most famous active lava domes include those at Merapi volcano in Java, at Soufriere Hills volcano in Montserrat, and at Mt. St. Helens in the U.S. state of Washington.Lava domes have formed in Mount St. Helens and experts say a lava dome is growing inside the Shinmoedake volcano in Japan. 

Here is a diagram for the four types of volcanoes:

What Causes Volcanoes to Erupt?

Before answering this question, we need to know the three layers of the earth. The crust is the outer layer of Earth. It is about 18 miles thick. It is the part we live on. The second layer is called the mantle. It is about 1,800 miles thick. The inner layer is called the core.

The Earth’s crust is made up of huge slabs called plates, which fit together like a jigsaw puzzle. These plates sometimes move. Between the Earth’s crust and the mantle is a substance called magma which is made of rock and gases. When two plates collide, one section slides on top of the other, the one beneath is pushed down. Magma is squeezed up between two plates.

What Happens in an Eruption?

During a volcanic eruption, hot melted rock called magma escapes from a vent, or opening, in Earth’s surface, or crust. Magma released from a volcano is known as lava.  It glows red as it flows out of the volcano’s opening. As it cools, it hardens into rock.

Strong volcanic eruptions throw bits of magma into the air. These bits cool into tiny pieces of rock, called volcanic dust or volcanic ash. Wind can carry volcanic dust thousands of miles away. Volcanic ash can coat the land for miles around the volcano.

Steam and poisonous gases also escape from volcanoes. Sometimes these gases are mixed with ash and other hot debris. This mixture travels outward in destructive fiery clouds, called pyroclastic flows.

What is The Difference Between Lava and Magma?

Magma is composed of molten rock and is stored in the Earth’s crust. Lava is magma that reaches the surface of our planet through a volcano vent.

Mafic magmas tend to form when the heavier crust that forms the ocean floor melts. They’re also the hottest variety of magma, reaching temperatures of between 1000 and 12000C. 

Silicic magmas, on the other hand, tend to form when the lighter continental crust melts. They’re also cooler than mafic magmas. silicic magmas are more dangerous.

What is the Ring of Fire?

The Ring of Fire is the geographical area around the edges of the Pacific Ocean. It is called so because it is shaped like a horseshoe. It is an area of frequent earthquakes and volcanic eruptions encircling the basin of the Pacific Ocean. 

The Ring of Fire has 452 volcanoes and is home to over 50% of the world’s active and dormant volcanoes. Ninety percent of the world’s earthquakes and 81% of the world’s largest earthquakes occur along the Ring of Fire.

The ring of fire was caused by the movement of the tectonic plates. These plates are nothing but enormous slabs of the Earth’s crust which move, break and then fit into each other like pieces of a puzzle. 

Tectonic plates are constantly moving and most tectonic activity occurs in the Ring of Fire region. These plates crash into each other, causing stress on the surface, break, slip, get stuck, build pressure causing earthquakes and volcanic activity.

Most of the active volcanoes are found on the Western edge of the ring of fire. They range from the Kamchatka peninsula in Russia through the islands of Japan, South East Asia and then into New Zealand. Mount Ruapehu in New Zealand is one of the most active volcanoes. 

How Many Volcanoes are There in the World?

There are around 1,510 active volcanoes in the world. We currently know of 80 or more which are under the oceans.

What is the Largest Active Volcano?

The world’s largest, active volcano is Mauna Loa in Hawaii, where famous coffee is grown in the rich volcanic soils. Mauna Loa is 13,677 feet above sea level. From its base below sea level to its summit, Mauna Loa is taller than Mount Everest.

Kilauea Volcano

Kilauea is the world’s most active volcano. It is located on the southeastern part of the island of Hawaii in the Pacific Ocean. It is the most active of the five volcanoes that together form the island of Hawaii. The volcano is between 210,000 and 280,000 years old and emerged above sea level about 100,000 years ago.

The name Kilauea means “Much Spreading” in Hawaiian. The volcano is 4,090 feet (1,250 meters) high. It is a long dome built of lava eruptions. Kilauea contains Halemaumau Crater. It is the volcano’s most active vent

Kīlauea erupted nearly continuously from 1983 to 2018, causing considerable property damage, including the destruction of the towns of Kalapana in 1990, and Vacationland Hawaii and Kapoho in 2018. 

Paricutin Volcano

The Paricutin Volcano is in the state of Michoacán in Mexico.This volcano is actually one of the Seven Natural Wonders of the World. It is known as a cinder cone volcano; this steep conical shape was created from debris.

Paricutin is a volcano in Mexico in the state of Michoacán. It is part of the Ring of Fire.  It is the youngest volcano in the western hemisphere, born in 1943. It is now 1,353 feet (424 m) above the valley, and 9,186 feet (2,800 m) above sea level.

This particular volcano grew very quickly. It started off as small eruptions of ash and stones. These small eruptions grew into eruptions the height of five stories in only a week! it continued to grow and in a year the volcano had reached 336 meters. The final height that the volcano reached by the end of its life was 424 meters.

The Paricutin Volcano continued to erupt for eight years until 1952. The volcano has remained silent since then. It is believed to be a monogenetic volcano and that means that when it is finished erupting it will never explode again.

YELLOWSTONE CALDERA

The Yellowstone caldera is located in Western United States. The area is also known as Yellowstone Supervolcano. The caldera measures 55 x 72 km (34 x 45 miles)  in size. It is located in Yellowstone National Park. The caldera at Yellowstone Park is the site of at least 3 great supervolcano eruptions in the past.

The caldera formed when pyroclastic material exploded out of the volcano partly emptying the magma chamber causing the roof to collapse. When the roof collapsed over the magma chamber it created a bowl shaped depression in the ground.

Major eruptions of the Yellowstone Volcano happen about every 600,000 to 800,000 years. Two of the past explosions have been among the most powerful ever. The huge magma chamber in the Yellowstone Volcano measures about 37 miles long, 18 miles wide and up to 7 miles deep in parts.

There are between 1,000 and 2,000 earthquakes each year at the Yellowstone Volcano. In early 2010, there were over 1,600 small earthquakes within the space of a few weeks.  Geologists studying volcanic activity at the park predict that a major volcanic eruption might not happen for at least another 30,000 years.

Arenal Volcano

The Arenal Volcano is The main characteristic of the national park in the northwest region of Costa Rica. It is an almost perfect cone with a height of 1633 m. The volcano has regular eruptions which create one of the most extraordinary natural landscapes of Costa Rica. 

Arenal Volcano is one of the most active volcanoes in Central America. Recent eruptions built a lava dome near this volcano. The temperature in the area ranges between 16°C in higher altitudes to 24°C in the lower altitudes. 

It remained silent between 1500 and 1900. People started considering it extinct.After remaining silent for these 400 years, this volcano erupted on July 29, 1968. Between 1995 and 2008, the Arenal presented activity both eruptive and seismic.

Submarine volcano

Submarine volcanoes are volcanoes which are under the surface of the world’s oceans. There are at least 1,500 active volcanoes on the surface of the earth, but it is estimated that there may be more than 10,000 volcanoes in the Pacific Ocean alone.

Almost all submarine volcanoes are located near the boundaries of two adjacent tectonic plates. As the tectonic plates move away or towards each other, lava that is present below the surface of the earth, is thrown out with pressure through a fissure on the earth’s surface. 

One of the latest examples of underwater volcanic eruptions is Surtsey island, south Iceland. The earth surface under the sea was literally lifted up during the eruption, and this resulted in the formation of Surtsey Island!

Magma is present in the mantle, the layer below the earth’s crust. When a crack relieves the pressure, the magma rises upward along with gases. This is known as the eruption of an underwater volcano. Underwater magma cools and solidifies much more quickly due to the presence of water. It often gets converted into volcanic glass.

Since most underwater volcanoes erupt at a depth of about 2200 meters below the sea level, where the pressure is more than 218 atmospheres, water cannot boil. Absence of boiling sound makes it difficult to detect an underwater eruption, even with the help of hydrophones. 

Fuego Volcano

Fuego volcano is an active stratovolcano in Guatemala. It is one of Central America’s most active volcanoes. It sits about 16 kilometres west of Antigua Guatemala.  It has erupted frequently since the Spanish conquest. Fuego recently erupted on 3 June, 2018.

“Fuego” is famous for being almost constantly active at a low level. Small gas and ash eruptions occur every 15 to 20 minutes, but larger eruptions are rare. On 9 August 2007 Fuego erupted, spewing lava, rock and ash. A new round of activity began on 19 May 2012, with lava flows and ejections of ash, and has continued into January 2016.

Kawah Ijen

Kawah Ijen is a composite volcano located at the easternmost part of Java island in Indonesia. The volcano is one of several active stratovolcanoes constructed over the 20 km wide Ijen caldera, the largest caldera in Java. 

Kawah Ijen consists of more than 10 stratovolcanoes, located within a radius of 20 km around the caldera of 1 km width and 200 meters depth. The crater lake of Ijen volcano is the largest acid lake in the world. Depending on the volcano’s activity, the lake can change its color from turquoise to green and even gray.

The volcano erupts to the lake’s surface not lava but the methane gas. Under the lake there is volcano magma – that is called lava when it comes to the surface. As the lake is very deep with dense water, magma remains locked at the bottom.

Kirishima Volcano

Kirishima is one of Japan’s most active volcanoes. Kirishima is a group of 20 volcanoes. These volcanoes include Takachihonomine, Nakadake, Ohatayama, Karakunidake, Tairoike, Ohachi, and Shinmoedake. 

Kirishima has erupted at least 67 times since 742 AD. The most recent eruption was in 1992. Eruptions produce pyroclastic material: scoria, lapilli, and ash. Lava has not been observed at any eruption of Kirishima in historic times. 

Mauna Loa volcano

Mauna Loa is one of five volcanoes that form the Island of Hawaii in the Pacific Ocean.  It is an active shield volcano with relatively gentle slopes, with a volume estimated at approximately 18,000 cubic miles. It has an area of 6 square miles and is 600 feet deep.

Mauna Loa has erupted 33 times since 1843. Its last eruption was in 1984.  Lava eruptions from Mauna Loa are silica-poor and very fluid, and they tend to be non-explosive. This is a shield volcano and that is why it is wide with gently sloping sides. Their eruptions are not violent.

Mayon Volcano

Mount Mayon is an active volcano located in the Philippines. It is called the world’s most perfect volcanic cone because of its symmetrical shape. It is a part of the Pacific Ring of Fire. Mount Mayon is 2,642 metres high. It is the Philippines’ most active volcano as it has erupted almost 50 times in the past 400 years. 

The first ever eruption of Mount Mayon took place in 1616. There were three eruptions that occurred in the 20th century in 1984, 1993, and then in 1999. The most recent eruption of this volcano occurred on January 13, 2018. The explosion contained steam, ash, and lava flow.

Bezymianny Volcano

Bezymianny was considered extinct until it erupted violently in 1955-56, after lying dormant for probably 1000 years. It is one of the most active volcanoes in Kamchatka. It is located on the southeast slope of the extinct volcano Kamen. 

A large portion of the volcano is made of a thick mass of light gray hornblende and andesites. Most of these lavas on the lower slopes of Bezymianny are covered by loose pyroclastic deposits. Several lava flows can be found on the upper portions of its slopes.

Mount Rainier Volcano 

Mount Rainier is the highest mountain of the Cascade Range in the U.S. It is an active volcano located in the southeast of Seattle, Washington. It last erupted in 1894. The top of the mountain is mostly covered by snow and glaciers. The mountain is 14,410 feet tall.

Mt. Rainier is considered one of the most dangerous volcanoes in the world. The mountain is believed to be 500,000 years old. This volcano had various names including Tacoma, Talol, Tahoma, Tacobeh, and Pooskaus. 

Krakatau Volcano 

Krakatoa is an Indonesian volcano which is responsible for an eruption that took place in August 1883.It was one of the most deadly volcanic eruptions of modern history. This explosion was so great that it triggered a tsunami that killed more than 36,000 people.

Krakatoa is a part of the Ring of Fire. The blasting from Krakatoa was so great that ash fell over an area of some 300,000 square miles. The sun was blocked out for several days because of the volcanic fallout in the atmosphere. The first recorded instances of volcanic activity on Krakatoa date back as far as 416 AD.

Abu Volcano

Abu volcano is a group of 56 smaller volcanic centers with no individual large central volcano. It is located along the Japan Sea coast. It consists of basaltic-to-dacitic lava flows, small shield volcanoes (some of which have associated cinder cones) and lava domes. 

Some of the volcanic centers of Abu volcano form offshore islands or submarine vents. The most recent eruption at the volcano was a central vent explosion at Kasa-yama ca. 8000 years ago.

Grímsvötn Volcano

Grimsvotn volcano is the most active volcano in Iceland. The volcano’s caldera lies beneath an ice shelf that is 200 meters thick.  It has an elevation of 1,725 m. It is a basaltic volcano which has the highest eruption frequency of all the volcanoes in Iceland.

The last eruption began on May 21, 2011 when plumes of ash shot into the air. Multiple earthquakes indicated that magma was on the move. The ash cloud reached a height of 20 km. The eruption released 2000 tons of ash per second during the first 48 hours of the eruption. The ash was so thick in parts of the island that it turned day into night. 

Popocatépetl Volcano

Popocatépetl is a volcano located in central Mexico. It is an active stratovolcano, which means it is shaped like a cone and has a crater at the top. It is the second highest peak in Mexico. It rises to 17,930 feet. Popocatépetl is One of the world’s most dangerous volcanoes. 

After almost 50 years of dormancy, El Popo came back to life in 1994. Since that time, the volcano has had occasional periods of activity, including another eruption in 2000. In 2000, the eruption of the peak was the most dramatic for over a thousand years. 

Stromboli Volcano

Stromboli is one of the most active volcanoes on Earth and has been erupting almost continuously since 1932. It is located at Stromboli Island in Italy. It is one of three active volcanoes in Italy.  The last major eruption of the volcano took place in 2019.

Stromboli is widely known for its unique eruptions. Strombolian eruptions are capable of ejecting cinders, lava bombs, and lapilli to heights of several dozen to several hundred meters.  Lava flows in strombolian eruptions are more viscous but short-lasting.

What is a Volcanic Neck?

A volcanic neck is the “throat” of a volcano and consists of a pipe-like conduit filled with hypabyssal rocks. It looked like the top of a toothpaste tube, but made of solid rock. In reality, a volcanic neck is the solidified magma trapped inside a volcano

After millions of years, the softer outer layer of the volcano erodes, and all that remains is the volcanic neck. Volcanic necks are somewhat rare because when a magma plug forms within a volcano, it often leads to an explosive eruption. 

There are some very famous volcanic necks around the world. Probably the most famous is Devils Tower in Wyoming. It rises 386 meters above the surrounding landscape, a lone prominence of rusty red rock.

What is Volcanic Lightning?

Volcanic lightning is a mysterious phenomenon that generally occurs at the early stages of a volcanic eruption. It happens in two places: close to the ground in dense ash clouds, and high up near the stratosphere in the plume of volcanic smoke. 

Volcanic lightning occurs mostly within the cloud of ash during an eruption, and is created by the friction of the ash rushing to the surface. It forms in a volcanic plume. Volcanoes that lack a thick volcanic plume usually lack volcanic lightning. 

As for Sky-high volcanic lightning, the plume of ash and water vapor rises from the volcano, and ice begins to form in its highest layers. From there, lightning forms the same way it does in a thundercloud. 

List of  Most Famous Volcanoes

1-  Mount Vesuvius, Italy: It is one of the most famous volcanoes of all time. Its last eruption was in 1944, although it famously erupted in AD 79. 

2- Krakatoa, Indonesia: This volcano on Indonesia’s Rakata Island erupted in 1883 and was one of the deadliest volcanic eruptions in history. Ash clouds spread up to 50 miles high with explosions so loud they could be heard in Australia, 2,200 miles away.

3- Mount St. Helens, United States: It is an active volcano located in Washington State, USA. The volcano is most famous for its devastating eruption on May 18, 1980.

4- Olympus Mons: Olympus Mons is one of the most famous volcanoes in space. It is situated on Mars and, according to scientists, is the largest volcano in the solar system at 16 miles high and 374 miles in diameter.

Damage Caused by Volcanoes

Volcanic eruptions can cause damage hundreds of miles away. Volcanic ash causes airplane engines to fail, destroys crops, contaminates water, and damages electronics and machinery. The ash carpets the ground, burying everything, sometimes even causing buildings to collapse.

Other explosive eruptions create fast-moving, hot clouds of volcanic ash, gas and rocks that travel down the sides of the volcanoes and destroy pretty much everything in their path.

Property damage from volcanic eruptions is difficult to estimate, because of differing value systems and changes in land use. One study estimates an average of $1 billion per year in property damage worldwide from volcanic eruptions.

The Benefits of Volcanoes

Despite the great damage they can cause, volcanoes also help us to live. Volcanic ash provides food for the soil around volcanoes which helps us grow plants to eat. The heat from some volcanoes is used to make energy to power lights, fridges, televisions and computers in people’s houses.

Most of the metallic minerals mined in the world–such as copper, gold, silver, lead, and zinc–are associated with magma found deep within the roots of extinct volcanoes. Over 4.5 billion years, the amount of water that has been produced by volcanoes has actually given us the water that we have on Earth. 

Hot water and steam trapped below the surface have been used to heat homes and greenhouses and to produce electric power in several countries, including Italy, New Zealand, Japan, Iceland, and the United States.

 

Volcanoes are openings of the Earth’s surface. When a volcano erupts lava, ash and gas is expelled from it. The hole at the top is known as the volcanic crater. Volcanoes can be active, dormant or extinct. Volcanoes hold a very hot liquid called magma. Once a volcano erupts, the magma will come out of the top of the volcano. After it has left the volcano, it is called lava.

The largest volcano in our solar system isn’t on planet Earth. It’s on Mars! The volcano is called Olympus Mons. There are around 1,500 which are active. Most volcanoes are found in countries that have coastlines on the Pacific Ocean. The largest volcano on Earth is in Hawaii. It’s called the Mauna Loa. 

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