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Natural causes of air pollution: Volcanic Eruptions

Volcanic Eruption Definition

A volcano is an open fissure on the surface of the earth. Active volcanoes are those from which lava, volcanic ashes, rocks, dust and gas compounds escape on a regular basis (10.000 years are considered regular with volcanoes, so you can feel safe if you have one around) due to the phenomenon of volcanic eruptions.

In the world there are several active volcanoes which cause air pollution, danger to life forms and massive destruction of the land and the environment. Indonesia is the country with most active volcanoes in the world with 76 of them and total of 147 volcanoes.

Causes of Volcanic Eruptions

There are many causes that can lead to a volcanic emissions, many of them are still unknown by humans, which volcano eruptions very hard to predict. However, volcanologists have made some researchers to determine a few catalysts of them:

  • Movement of tectonic plates: whether it is because one is pushed under another one or two tectonic plates are moved away from each other, this creates a massive movement on the layers of planet earth (changing the structures of magma, sediments and seawater) and cause a volcano to erupt.
  • Decreasing temperatures: the volume of magma changes when it crystalizes, so it can push away liquid magma and create a volcanic eruption.
  • Decrease in external pressure: this fact provokes an increase in the internal pressure of the volcano and causes and eruption if it is not capable of holding back the lava.
  • Buoyancy of the magma: if the density of the magma between the zone of its generation and the surface is less than that of the surrounding and overlying rocks, the magma reaches the surface and erupts.
  • Pressure from the exsolved gases: andesitic and rhyolitic magma compositions contain dissolved volatiles (gases) such as water, sulfur dioxide and carbon dioxide. This gas bubbles are held by magma, but just like a carbonated drink, the bubbles of gas rise to the surface of the magma chamber creating a volcanic eruption.
  • Injection of a new batch of magma into an already filled magma chamber: this phenomenon causes some magma to move up and spill or even erupt at the surface.

Effects of Volcanic Eruptions

Volcanoes have huge impact on our society and environment when they erupt, here there are some of the many positive and negative effects of volcanic eruptions:

  • Negative effects: volcanic eruptions, which sometimes generate earthquakes, can destroy landscapes, natural resources, wildlife and human lives and their properties. This phenomenon can also discharge ashes very high into the atmosphere, having negative consequences on the ozone layer. Moreover, ash and mud can mix with rain and melting snow and create situations like lahars (also called mudflows) or acid rain. In other words, volcanic eruptions can destroy civilizations, like what happened to Pompeii.

  • Positive Effects: sometimes eruptions can leave an extraordinary beautiful and natural scenery, attacking tourists to the area. However, one of the most useful positive effects is that they often leave potential for geothermal energy, making life more easy for those around the area. Finally, some volcanic eruptions provide valuable nutrients for the soil, which are later used as fertile soils for agriculture.

Types of Volcanic Eruptions

Air Pollution of Volcanic Eruptions

Volcanic Eruptions release massive quantities of solid pollutants and gases, forming enormous clouds that can affect areas miles away from the volcanic eruption. Therefore, volcanoes are an international form of air pollution, but not just for us, as a lot of this greenhouse gases and aerosols go directly into the atmosphere.

Every volcanic eruption is different on impact, and therefore different on the quantity and a variety of pollutants emitted. On average the outgassed composition release is 79% water vapor (H2O), 11,6% carbon dioxide (CO2), 6,5% sulphur dioxide (SO2) and 2,9% of other pollutants.

However, the range of pollutants released on a volcanic eruption include: carbon dioxide (CO2), sulphur dioxide (SO2), hydrogen sulfide (H₂S), hydrogen (H₂), hydrogen fluoride (HF), hydrogen chloride (HCl), bromide oxide (BrO) and carbon monoxide (CO). Highly exposure to these gases has detrimental impact on living organisms both terrestrial and marine.

On the other side, particulates are another source of air pollution produced by volcanic eruptions. Mainly ashes and including all types of sizes, the ones that help forming toxic clouds are usually PM10, PM2.5, PM0.3 and thinner.

These pollution clouds can travel major distances, like crossing oceans, dangerously affecting people and environments who didn’t even notice the eruption. If you are facing a polluted cloud caused by a volcanic eruption, you may want to have a look at the following content on what to do and how to prevent these events.

What to do before, during and after a Volcanic Eruption

Before a Volcanic Eruption

There are several precautions you have to take into account before a volcanic eruption, and it is good to discuss them with your family members (including kids) before the event to prevent nerves and panic.

The first step is to have a household evacuation plan (that includes your pets). If you need guidance creating one you can find all you need to know and some templates here.

Secondly, as during the volcanic eruption you might lose electric supply, you need to have a flashlight, a battery radio and extra batteries for both. It is important to keep yourself up to date. We will write about it below, but during the previous days stay informed about the governmental media, community’s risk and response plans.

Thirdly, you will need health protection to ashfall and air pollution. To protect your eyes it is recommended having a pair of goggles, and to protect your respiratory system you should buy industrial protection face masks. Note that the majority of common pollution masks are not valid, you should have one approved for industrial and extreme purposes.

Finally, as any scenery is possible, you need to be prepared to live indoors for long periods without electricity power nor drinking water so buy food (if possible durable goods) and bottled water to survive you and your family members a few weeks. Make sure to have all the outdoor stuff and you want to keep safe inside, volcanic eruptions can damage any furniture, machinery or material.

During a Volcanic Eruption

If your outdoors you should quickly look for a shelter indoors. If it is not possible stay out of designated restricted zones, areas downwind of the volcano and river valleys downstream of the volcano. Take into account that even if you are miles away from the eruption you can experience harmful consequences.

In the case you get caught by an ashfall wear goggles (never contact lenses), a dust mask prepared for industrial and extreme purposes and a keep as much of your skin covered as possible.

On the other hand, if you are indoors you should be constantly listening to a local station on the battery radio for updated emergency information and instructions. It important because your area can be at any moment evacuated. During the indoor period, make sure to close all window, doors, and dampers to keep volcanic ash from entering.

In case of evacuation, strictly follow the instructions issued by local or national authorities and put your previously studied household evacuation plan. This rule is the most important one because even though it may look safer to stay home, take into account that your life must be in danger.

After a Volcanic Eruption

If you pass a volcanic eruption you will surely never forget it. There are some tips you should take into account to return to normality as soon as possible.

Firstly, you should not stop listening to local news for authorities updates, if you were evacuated, don’t return home until the authorities say to do so because it is safe. If people around you are injured, check the zone is safe for you and then call an ambulance and provide first aid (if you know something about it). Your family and friends might be worried as well, so tell everyone you are safe.

Secondly, even though the eruption has passed, if possible stay indoors and use the pollution mask (indoors and outdoors), because pollution particles (mainly ashes) will still be floating in the environment, and these can be extremely harmful. Moreover, keep animals away from ashes and wash them to prevent them from eating ashes.

Emotional recovery can be difficult because you may see some astonishing images and receive some terrible news. Here is a link to help you with this recovery.

If you have to return home try not to drive on heavy ashes roads because these are extremely harmful not just to humans health, but also to car engines. Never stop wearing any of the protective clothes, you cannot allow to expose yourself even for 30 seconds.

Once you get there, take pictures of the damages caused by the volcano for insurance purposes. The next step is to start cleaning your house from ashes and other volcanic materia, starting by the roof and gutters, which can cause your house to collapse. To help you with this task, read the following link for proper guidance.

Last Volcanic Eruption

Here comes an interesting fact about volcanic eruptions: any time there are several volcanoes on an eruption process. Volcanic activity is much more powerful and regular than we usually think. To know what volcanoes are erupting today, click the following link.

Largest Volcanic Eruption

World’s history has seen some supervolcano eruptions, often called big bangs on the earth, and science explains that these major catastrophes occurred before human life was born.

However, during humans history there has been some major eruptions as well, and since 1980 we have been measuring their impact throw the VEI (Volcanic Explosivity Index) indicator. VEI is measured just like earthquakes, on a scale from 1 to 8, and each number is ten times greater than the previous one.

In the last 10.000 years there haven’t been any VEI-8 volcanic eruptions, luckily for us, but on the following list we name some of the most recent major volcanic eruptions:

  • Tambora – April 10, 1815
  • Krakatoa – August 27, 1883
  • Santa María – October 25, 1902
  • Novarupta – June 6, 1912
  • Pinatubo – June 15, 1991

2 thoughts on “Natural causes of air pollution: Volcanic Eruptions

  1. If at home and still have electricity, should one turn off the central air and furnace if using forced hot air?

    1. The most important thing to remember is to protect your home from volcanic ashes. Close windows and turn off all kinds of gadgets that can help the ashes go indoors. The authorities will give more details and instructions in the case of a volcanic eruption take place.

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