tectonic plate


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.


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What is a Earthquake?


Earthquakes, temblors, quakes, tremors: These names are used to describe the sudden release of energy in the earth’s crust causing movement.

Firstly, lets get to know some terms that are associated with earthquakes:

Earthquake: A sudden and violent movement of a portion of the earth’s crust, and the series of vibrations that follow.

Earths crust: This is the solid thin layer that covers the outside of the earth. To put it in perspective, think of it as the skin on the outside of an apple.

Plate: A plate is a section of the earths crust. Plates slide along either beside, over or under each other, causing friction and pressure between the plates.

Magnitude: The amount of energy released during an earthquake, which is computed from the measurement of seismic waves.

Fault:  The gaping hole which can occur as a result of an earthquake. This hole can be the size of a small crack to the size of an olympic swimming pool or larger.

Fault zones: Where giant rock slabs that are made up of the earths crust collide and slide against each other regularly, causing the land to be unstable.

Seismic waves: These waves are the vibrations and movement that travel from the earthquake fault at very high speeds. The vibrations of these waves are what cause the most destruction during the earthquakes.

Earthquake facts and information
Urban Destruction after a Earthquake

This gigantic release of energy creates what are known as ‘seismic waves’. These waves cause the one of the most terrifying and destructive acts of nature on the planet. These natural phenomena are sudden, violent shakes of the earth that are caused by the breaking and moving of the rock in the earths crust as it releases strained energy that has built up over a long period of time. Earthquakes occur when the energy has built up so long that is snaps and cause smashing and crashing under the earths surface and between the plates.

The ‘seismic activity’ of an area holds refers to the frequency, type and size of earthquakes that are experienced over a period of time. Frequency means the strength of the earthquake.

Measurements of earthquakes

Measurement of earthquakes are measured using readings from instruments called seismometers. Scientists use the ‘magnitude rating’ to measure earthquakes. This rating measures the strength of the seismic waves and the period of time they lasted for. An earthquake measuring between 3 and 5 on the magnitude rating is considered normal. When they are between 3 and 5 there usually is not too much damage done, but the tremors can be felt in the ground. When the magnitude rating is between the numbers 5 and 7, this is regarded as moderate to strong. Earthquakes of this magnitude do not cause a huge amount of damage or loss of lives, but can leave some destruction in its trail, like cracks in the ground, landslides. Major earthquakes are rated between 7 and 8, and 8 or more is a seriously large natural disaster.

The largest earthquake ever recorded was slightly over 9 on the magnitude rating. This earthquake occurred in northern Japan in 2011, killing hundreds of people and destroys buildings within the area. This earthquake also caused a 23 foot tsunami and was followed by more than fifty aftershocks.

Earthquakes can cause many other natural disasters once they strike, here are their names and a brief description of each:

  • Tsunami – Are giant sea waves that are produced by the sudden violent movement of the earths plates of volcanos under the water. The time periods of these waves can last up to an hour, causing massive devastation as seen in Sri Lanka in 2004.
  • Fires – Fires can be caused when earthquakes damage electrical power stations or gas lines. These fires can be impossible to stop sometimes. In 1906 in San Francisco, fire caused by an earthquake killed more people than the earthquake itself.
  • Landslides and avalanches – Earthquakes can produce unstable slopes which can lead to the moving of the ground, which is called a landslide. Landslides can cause sever damage after an earthquake occurs, for example it can crash down homes, cars of even people.
  • Floods – A flood is an overflow of water that reaches land. This occurs when a lake, dam or river overflows due to the movement of land due to an earthquake or landslide. Floods can have devastating effects on terrain, animal life and human life.
  • Human and animal death – Of course, earthquake can cause severe injury and loss of life for both humans and animals. Properties can also suffer, and the collapse of buildings are expected when highly measured earthquakes occur. The aftermath of an earthquake can cause disease and lack of basic necessities for people.

Natural Disaster: Earthquakes

The earthquakes that occur anywhere on the planet that has a large amount of built up elastic strain energy to push a piece of the earth’s crust, called a plate. The sides of the fault can move past each other with no interruption only if there is nothing in the way. If there is something in the way of the moving plate, this can lead to the formation of stick-slip behavior. Once the fault gets stuck in a position, the pressure will build up continuously. This energy will become stored energy. The energy can be released due to a combination of elastic strain seismic waves, heating caused by friction of the fault surface, or cracking of the plate. When one or more of these occur, an earthquake will be caused.

temblor facts and information
A rescue dog

Earthquake clusters

Most earthquakes form part of a sequence, related to each other in terms of location and time. The ‘Ring of Fire’ is a rim along the Pacific Ocean where 80% of the planets earthquakes occur. These earthquakes are also due to the amount of volcanic activity in the area. In a 25000 mile horseshoe shape, the Ring of Fire causes a spontaneous series of faults, volcanic arcs, belts, plate movements  and oceanic trenches. The Ring of Fire contains 452 volcanoes, 75% of which are active. About 90% of the world’s earthquakes and 81% of the worlds largest earthquakes occur in this area.

In general when a magnitude of 8 hits anywhere in the world  it can cause a lot of damages and loses. On average around 10,000 people die on a yearly basis due to earthquake. Most of the human deaths caused by the result of  earthquakes are collapsing buildings. The destruction of buildings, bridges and historical monuments is often caused by mudslides, floods, tsunami or fire. The small trembles that occur after a large earthquake can make rescue operations very difficult and impossible especially in areas surrounding buildings, bridges etc.

Religious and cultural facts and beliefs about earthquakes:

  • In Greek mythology, earthquakes were caused by the god Poseidon. It was believed that when he was in a bad mood, he would strike the ground with a trident and cause many calamities. He would also cause earthquakes to get revenge.
  • In Japanese mythology, earthquakes were caused by the thrashing about of a giant catfish that was named Namazu who lived under the earths crust.
  • In popular culture, the portrayal of earthquakes is shaped by the memory of cities that were destroyed, such as San Francisco in 1906.


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