Volcano Eruption

What Is A Volcanic Eruption?


A volcanic eruption is one of the most dangerous and magnificent natural disasters.  When a volcano erupts, the volcano sends out ash clouds, lava and even volcanic bombs.  There is a high risk of danger from slow moving lava; though, the lava might move slowly, it is very dangerous and can cause a lot of damage to property and human life.

Volcanic eruptions comprise of 3 stages:

  • Magmatic eruptions – when gas is released under decompression.
  • Phreatomagmatic eruptions – when a thermal contraction comes from water.
  • Phreatic eruptions – when steam erupts.

The Magnitude of Volcanoes

When there is an earthquake, little vents are created in which magma is allowed to form.  This is pushed up through these vents and towards the crust of the volcano.  Steam vents are created when the magma reaches a certain level and reaches a boiling point which begins the eruption.  The eruption might result in a total eruption.  This is when gas driven explosion send magma to the volcano’s crust creating lava outpouring from the volcano.

Some eruptions are not as strong as others.  All volcanic eruptions can vary in strength; with some not reaching any civilians or causing too much damage.  However, others can spread over a vast area, sometimes reaching several miles from the volcano.  Some eruptions do not always contain lava flow or lava fountains which aren’t always very dangerous.  However, some eruptions can be on a huge scale, very violent and very, very dangerous with explosions heard from the volcano.

Some eruptions can be passive and not very dangerous however; some are explosive and can be very and high dangerous.  Some volcanoes do not just erupt from their peeks, some can have eruptions at any part of the mountain, it’s not just the peeks that are the most deadly for volcano eruptions.  One of the biggest and well known eruptions was in Pompeii.

The entire city of Pompeii was buried when the volcano at Pompeii erupted.  However, this is only one example of a type of eruption; another type of eruption is in Norway, a volcano that had been dormant for years suddenly became active, however, the local towns were evacuated and the volcano erupted. However, there was no great scale eruption.  Lava flowed but didn’t reach the town, this was a very small eruption compared to many others.

When Can An Eruption Happen?

Volcanic eruptions happen deep down inside the earth.  When the earth’s tectonic plate’s shift, it causes more than just earthquakes, it can create new volcanoes or vents.  Underneath the surface of the earth, debris, gases from the planet and molten rock are stored creating new formations of vents and volcanoes.

As soon as the magma thickens and builds up with the gases of planet can create explosions and cause lava to flow upwards and have ash released into the air causing thick clouds of smoke often seen overhead volcanoes. If there is an increased magma but a decrease of planet gases, then the eruption will not be as great.

However, lava can reach an amazing heat possibly even 2000 degrees Fahrenheit; sometimes it can be even higher than that.  Lava can actually destroy everything in its path, even an entire village.  There can be huge rocks or even boulder types reigning down from the volcano and onto populated areas.  There can also be toxic gases and ash which causes severe lung problems to many vulnerable people including children and elderly people.

Volcano eruptions can happen at any given time.  If there is a change to the tectonic plates in which a volcano sits on, then it can erupt at any given time.  There is no set time as to when they will erupt or how much damage they’ll cause.

Volcano eruption facts
Anak Krakatau Volcano erupting

Understanding the Volcanoes

When there is a volcanic eruption, there could be many other dangers which occur.  These things can be such as flash floods, mudflows, landslides and rock falls, and even earthquakes. However, there can also be things such as fire and acid rain that follows a volcano erupting.  It might not seem as though there are many active volcanoes erupting but there is a great deal of active volcanoes and the fact that they haven’t erupted doesn’t mean it will always be like this.  There are dangers every day from active volcanoes.

What Can You Do Before A Volcanic Eruption?

There are steps which anyone can take before a volcano erupts and they are very simple steps.  These small but simple steps can help protect homes, and protect your families also in the event of a volcanic eruption.  If you live in an area which has an active volcano, even if it might be up to 100 miles away, there is still a risk because a volcano can erupt at any time.

  • Have An Emergency Supply Kit

This can be a small but important kit of some of the simplest items such as water, and non perishable foods.  You should look to add batteries, radios, battery powered or hand cranked radios.  You can also have torches or flashlights just in case of a power cut or blackout; and have a first aid kit should anyone get hurt.

All of these supplies should be kept in a location which is easy to reach such as a car just in case you need to be evacuated or are being told to do so.  If possible, try to add breathing masks or goggles to see through thick ash clouds.

  • Emergency Plan

A disaster such as a volcano erupting can happen at any given time and it does mean your family mightn’t be at home when it happens.  This is why you do need to think about getting in contact with other family members and meeting up again.  You need to think carefully about all eventualities and have a good plan to get the family reunited once again.

These are simple plans but if you do live in an area very close to an active volcano, they could end up saving your life and your family’s.

You might not realize or understand that a volcano is active or is about to erupt either, however, when a volcanic eruption occurs, you have to be vigilant.  You have to be aware of what could happen and how a volcano works.

The World’s Natural Disaster

When an eruption occurs, lava can spill over and can absolutely cause mass devastation.  Even if the volcano isn’t moving fast towards the local town or village, there are still many dangers that can cause harm.  The ash clouds can be very dangerous to a person, as is the poison gases and flying debris and rocks.  There are many dangers to volcanic eruptions, though this is a natural disaster that cannot be tamed or predicted.

It might sound as though volcanoes aren’t that dangerous if they haven’t been active for years but they’re still dangerous.  They have intense heat from lava flows and of course the acid rain can all become dangerous.


Volcano Eruption Related Articles

Classification Of Volcanoes


When studying the volcanoes in the world it is important to understand what the classification of volcanoes is and how it works. There are several factors that go into account when attempting to classify a volcano into a group and that includes things like recent activity, periodicity of eruptions, size, potential impact and others. Though it is not common to hear it volcano eruptions are actually not that rare. More often than not the classification of volcanoes refers to the life cycle and that could define them as active, extinct or dormant. However, a volcano can also be classified by the composition of the structure and that would mean that it can be a shield, conical or stratovolcano. Finally they can also be classified because of its eruption which could be quiet or explosive.

Active Volcanoes

A volcano will be classified as an active volcano if at the present time it is expected to erupt or is erupting already. One of the best examples of this classification of volcanoes would be Kilauea which has been erupting since 1983. There are a total of close to 1,500 of such volcanoes on the planet. Every year somewhere between 50 and 70 volcanoes will erupt.

Dormant Volcanoes

The classification of volcanoes which is called dormant would be a volcano that is not erupting or predicted to erupt in the near future. However, it has done so in recordable history. A dormant volcano is also expected to have an eruption sometime in the future. Sometimes the difference between a dormant volcano and an active volcano can be pretty small. That is because even though a volcano can be dormant for hundreds of years it is still expected to have an eruption in the future.

Mauna Kea is a volcano which is located on Big Island and its last eruption took place 3,500-4,000 years ago. However scientists believe that it will erupt again. What makes that volcano dormant is that currently there is no prediction as to when that eruption could take place. A dormant volcano could be very dangerous because people in the surrounding areas are usually not prepared and complacent leaving close to the mountain. Before its eruption in 1980, Mount St. Helens was dormant.

Extinct Volcanoes

An extinct volcano is a volcano that no one expects will ever have another eruption. One such volcano is also located on Hawaii’s Big Island and its name is Kohala. The last time that Kohala erupted was close to 60,000 years ago. As of now scientists do not believe that volcano will ever be active again. Keep in mind that this classification of volcanoes that are extinct is not necessarily definitive as some have gone through what is called rejuvenation.

Type Classifications

Classification of volcanoes can also be done because of the type of composition and structure of the volcano. A shield volcano is dome shaped and low. These volcanoes are mountains that have been shaped by the flows and can cover larger areas. The simplest form of volcanoes would be the cinder cone type. These volcanoes have erupted from one single vent and a bowl shaped crater will be found in the summit. The most common type of volcano is the strato or composite. These are tall mountains that have steep sides and which have alternated magma and layers of rock.

Eruption Classification

There are two types of classification of volcanoes based on eruption and these are central or explosive and fissure or quiet. An explosive eruption happens because of a buildup of gas under very viscous slow flowing and thick magma. These types of eruption are very violent and rapid; more often they will spew volcanic material, lava and ash onto a large area. A fissure or a quiet eruption will emit a lot of lava from a fracture or fissure. Because lava would usually have a low viscosity, the gas can easily escape.

Samples Of Volcanoes

There are several places in the world which can demonstrate the classification of volcanoes but most active volcanoes will be found in the Pacific Ring of Fire. There are, however, volcanoes not located in the Pacific which are active; some of them include Etna and Vesuvius, Mount Pinatubo and Stromboli.

Classification of volcanoes that are dormant will include a lot of the volcanoes still found in the Ring of Fire and other places nearby. One example would be Mount St. Helens previous to its 1980 eruption. Before a dormant volcano is about to erupt it is usually proceeded by small tremors and earthquakes.

Finally when you are looking at extinct volcanoes you can look at the ones in the Eiffel district in West Germany as well as several volcanoes in USA. There are two volcanoes in Northern Ireland which are also extinct volcanoes and those are Skye and Mull.


Classification of Volcanoes Related Articles

Famous Volcanoes


Volcanoes are one of the most awesome natural events that the world can ever see, and they are also among the most dangerous. Currently there are approximately 1500 active volcanoes in the world but an active volcano can be described as one that has had an eruption at least within the last ten thousand years. There are many volcanoes that have been dormant for a lot longer than that and yet they could be some of the most dangerous if they were ever to explode. There are volcanoes in most of the world and some you would not be able to see even if you were standing on them even though they are some of the most famous volcanoes. Some areas are more active than others, but the most famous one is the Pacific Ring of Fire.

The Ring Of Fire

The Pacific Ring of Fire is the area in the Pacific Ocean, which has the most active volcanoes in the world. By the latest calculations over 75% of the active volcanoes in the world are located here. Because of that, you will find some of the world’s most famous volcanoes in that area. The area extends from the Chilean coast in South America to Alaska, to the East Coast of the Asian continent, down to Australia, New Zealand, and the Pacific Islands. There are a total of 452 known volcanoes in the Pacific Ring of Fire which is also known for the severity of its earthquakes.

Most Famous Volcanoes In The Ring Of Fire

Because of the amount of volcano activity in the Ring of Fire, some of the world’s most famous volcanoes can be found here. Some of the names you may recognize right away are Mount Saint Helens in Washington State, Kilauea in Hawaii, Mount Yasur in Vanuatu, Santa Maria in Guatemala, and Sangay in Ecuador all of which are still very much active. Another couple of recognizable names in the Ring of Fire are Mount Fuji in Japan, and Mauna Loa in Hawaii.

World’s Most Active Volcanoes

One thing that is important to note is that most of the famous volcanoes are also the most active in the world. Kilauea in Japan is one of the world’s most active volcano at the moment with its last spew of lava happened in 2011. The Nyamuragira volcano in the Democratic Republic of Congo is the most active volcano in Africa and it has erupted at the very least 34 times since 1882. Mount Etna, which was believed by ancient Romans to be the home of the god of fire Vulcan has a continuous history of eruptions that dates back over 3500 years. Piton de la Fournaise or Le Volcan as it is known to locals at Reunion Island has seen over 150 eruptions since the records show it in the 17th century.

What Happens When A Volcano Erupts

To understand famous volcanoes and even volcanoes in general it is important to understand eruptions. Before an eruption takes place there is a lot of commotion beneath the surface which involves melted rock. The substance that is created during that commotion is what is later spilled while the eruption takes place. The name of the molten lava that will flow down the side of a volcano is what is known as magma, but before the magma is expelled out it needs to rise and that is created by disturbances of low and high pressures.

The eruption does not have to be the big explosion that people associate with famous volcanoes. There are mild eruptions, which only cause steam blasts. Others are still considered mild but will have lava run down de side of the volcano and ejected ash or rock fragments. There are however more dangerous and stronger eruptions which can cause a lot of damage to the surrounding area. A Vulcanian explosion will contain solidified rock, which will produce a pyroclastic flow.

Volcanoes With The Potential Of Being The Deadliest

Some of the world’s most famous volcanoes have destroyed entire cities and killed everyone in the nearby area. Mount Vesuvius for example destroyed the entire city of Pompey and archeological records show the devastation it caused. There are some volcanoes that could cause the same type of damage to cities today with the difference that the population around those volcanoes is even larger than that of ancient Pompeii.

The city of Kagoshima in Japan has 680,000 people and the Sakurajima volcano located nearby has been experiencing small explosions since 1955. Catania near Mount Etna has 300,000 people in the area, which has seen the dangers of Mount Etna when an eruption destroyed some of its structures in the 1600’s. The 450,000 people in Pasto Colombia have been on guard due to the Galeras Volcano nearby. In 2005 then were forced to wear goggles and facemasks because of an explosion. Seattle’s population of 608,000 live in that shadows of Mount Rainier and though the volcano is quiet for now, its past history is anything but. Finally, close to a million people live in Naples, Italy. Their biggest and scariest neighbor is Mount Vesuvius, which has destroyed an entire city and the surrounding areas in the past. These are just some of the famous volcanoes near people, but there are a lot more.

Super Volcanoes

If the most famous volcanoes listed before were to erupt, they could cause a lot of destruction, but that destruction would be nowhere near to what would happen if a super volcano were to erupt. There are several of these volcanoes and they have caused severe destruction in the past. Their eruptions are measured using the Volcano Eruption index or VEI. The most severe eruptions are those that reach the VEI8 classification and there have been 10 of those eruptions in recorded history, 5 of which were in the US.

What Would Happen If A Super Volcano Erupted Today?

If a super volcano like the one found at Yellowstone Park in the US were to erupt today it would instantly be a famous volcano, but there would not be as many people to tell the story. The last time that the Yellowstone volcano erupted was 640,000 years ago and it is believed that it was the main cause of the latest ice age. If an eruption of that magnitude were to happen today the people nearby would stand no chance as they would be hit by 500 degree lava. Even if the lava does not reach you the ash would and that would cause you to choke to death as you inhale it.

People in other parts of the world would not get away unharmed because the global temperatures would drop by a minimum of 21 degrees. That would cause plant life and animal life to die off, leaving the people in the rest of the world without food and very cold. In other words, the great majority of people would starve.

The problem is that some scientists believe that the volcano at Yellowstone Park erupts once every 600,000 years, and if that is the case then we are overdue. No one knows when one of these famous volcanoes will erupt, but when they do it will be a spectacle that could end life as we know it.


Famous Volcanoes Related Articles



Volcanoes can be both very impressive and highly destructive. While most people are used to watching the big shows of lava spewing from volcanoes on TV and some while volcano watching during their vacations, no one can possibly be prepared to the amount of disaster that a supervolcano would cause. In recorded history no one has experienced the fury of a supervolcano first hand but it is believed the impact that such an eruption could have would be deadly not only to people in the vicinity, but even for people on the other side of the world.

Known Supervolcanoes (Yellowstone)

There are six supervolcanoes which are currently known by most people. The many visitors of Yellowstone Park may not realize it, but they are walking on top of one of the biggest threats to humanity.  To understand how massive an eruption from one of these volcanoes can be, we can look at what took place in the Yellowstone Caldera volcano that erupted 2 million years ago. The size of the eruption was so big that the amount of ash ejected was over 8,000 times the amount ejected by the 1980 eruption of Mount St. Helens.

Long Valley Caldera

The Long Valley Caldera is located in the eastern side of the state of California and it is second only to Yellowstone. It’s last eruption, though not as massive as the one in Yellowstone supervolcano could still cause tremendous damage to the population in the world; that eruption took place close to 760,000 years ago, and the result was 2,000 times the size of the eruption of Mount St Helens.

Valles Caldera

The Valles Caldera is located northern of New Mexico and its last supervolcano eruption happened over a 50,000 years ago. The effects of the supervolcano eruption at the Valles Caldera were felt as far as Iowa as some ash and rock landed all the way there.

Lake Toba

Lake Toba in Indonesia is big; in fact it is actually bigger than the Yellowstone caldera. The last time this supervolcano erupted was 74,000 years ago.  The eruption that was presented was 5,000 times larger than the Mount St. Helens eruption and it has been suggested by several scientists that this event was so massive that it changed the trajectory of humanity and resulted in what we see today.

Taupo Caldera

The Taupo Caldera is located in New Zealand and though now the view that you get is that s a spectacular lake, that lake was created by an eruption 26,500 years ago; the basin which was left after the eruption is what became the lake you see today. This massive monster is not a dead supervolcano. Volcanic activity can be observed in the area in the form of venting and hot springs.

Aira Caldera

This Caldera in Japan is pretty close to the city of Kagoshima. This is not a sleeping giant; in fact there are several earthquakes in the area caused by it and the Sakura-jima volcano is still active. Those are clear signs that the caldera is still active and it is a reason for concern for scientists.


Supervolcano Related Articles