Montserrat Volcanic Devastation

The Most Dangerous Volcanoes in the World – A Tier List

As I mentioned in the previous post, I would be curating a list of what I believe are the most dangerous volcanoes in the world. This list uses a variety of factors to determine which volcanoes are a greater risk to loss of life. Here are the factors I used to determine which are the most dangerous volcanoes in the world.

Click the links below to jump to more detailed explanations on the tiers and the volcanoes featured within each danger tier.

Tier 1 Volcanoes – Inevitable Disasters
Tier 2 Volcanoes – High Disaster Potential and Likelihood
Tier 3 Volcanoes – Potential for a Megadisaster
Tier 4 Volcanoes – Outside Shot at Causing a Large Disaster

Tier 1 Volcanoes
Campi Flegrei – Italy
Taal – Phillippines (Luzon)
Mayon – Phillippines (Luzon)
Aira – Japan (Ryukyu Islands and Kyushu)
Apoyeque – Nicaragua
Tier 2 Volcanoes
Ata – Japan – Kyushu
Tolima, Nevado del – Colombia
Guagua Pichincha – Ecuador
Pululagua – Ecuador
Cotopaxi – Ecuador
San Salvador – El Salvador
Agua – Guatemala
Almolonga – Guatemala
Vesuvius – Italy
Merapi – Indonesia – Java
Amatitlan – Guatemala
Guntur – Indonesia – Java
Tacana – Mexico
Rainier – USA (Cascades)
Tatun Group – Taiwan
El Misti – Peru
Tier 3 Volcanoes
Baker – USA (Cascades)
Tenerife – Canary Islands
Galeras – Colombia
Chimborazo – Ecuador
Cayambe – Ecuador
Izalco + santa ana – El Salvador and Honduras
Santa Ana  + santa ana – El Salvador and Honduras
Shikotsu – Japan – Hokkaido
Fujisan – Japan – Honshu
Nantai – Japan – Honshu
Cereme – Indonesia – Java
Merbabu – Indonesia – Java
Slamet – Indonesia – Java
Agung – Indonesia (Lesser Sunda Islands)
Malinche, La – Mexico
Colima – Mexico
Mt. Unzen – Japan (Kyushu)
Soufriere Guadeloupe – Guadeloupe
Tier 4 Volcanoes
Aso – Japan (Kyushu)
Hakone – Japan – Honshu
Galunggung – Indonesia – Java
Raung – Indonesia – Java
Avachinsky – Russia – Kamchatka Peninsula
Koryaksky – Russia – Kamchatka Peninsula
Matutum – Phillippines – Mindanao
Cameroon – Africa (western)
Madeira – Portugal – Azores
Agua de Pau – Portugal – Azores
Sete Cidades – Portugal – Azores
Ruiz, Nevado del – Colombia
Hokkaido-Komagatake – Japan – Hokkaido
Kuttara – Japan – Hokkaido
Toya – Japan – Hokkaido
Harunasan – Japan – Honshu
Akagisan – Japan – Honshu
Adatarayama – Japan – Honshu
Myokosan – Japan – Honshu
Azumayama – Japan – Honshu
Iwakisan – Japan – Honshu
Asamayama – Japan – Honshu
Iwatesan – Japan – Honshu
Bandaisan – Japan – Honshu
Niigata-Yakeyama – Japan – Honshu
Baluran – Indonesia – Java
Batur – Lesser Sunda Islands
Buyan-Bratan – Lesser Sunda Islands
Orizaba, Pico de – Mexico
Pelee – Martinique – West Indies
Chiracha – Africa – Rift Valley
O’a Caldera – Africa – Rift Valley
Corbetti Caldera – Africa – Rift Valley

Factors that Influence a Volcano’s Danger Level

Presence of Nearby Population

As a baseline, having population nearby is extremely relevant in determining whether a volcano can create a large-scale disaster. The larger the population is within close proximity, the more likely it is that even a small eruption can cause a catastrophe.

Activity Level

There are many volcanoes that have large populations living within a 30 kilometer radius, but should we really say that all these volcanoes are extremely dangerous? While volcanoes waking up out of deep slumbers to erupt a large eruption is always a major risk, it’s impossible to predict or analyze which volcano may do this. As a result, I gave a heavier weight to volcanoes that have shown holocene activity, most notably explosive holocene activity.

Ability to Reasonably Cause a Catastrophe in the Next 50 years

This is related to activity level, but I wanted to only include volcanoes that within reason, could cause a major catastrophe in within the next 10 years.

This includes downgrading certain volcanoes that would otherwise fit the criteria, but are likely in a repose period of not being able to create a large eruption for a little while due to a recent large eruption (such as Pinatubo, or to a lesser extent, Santorini).

Similarly, this means that we are leaving out potential supervolcanoes such as Toba or even Taupo since the mega-eruptions simply come too infrequently and are impossible to predict.

Influence of Water and Other Environmental Factors

One of the common themes of many of the largest volcanic disasters in history is the influence of water. The majority of the deaths from Krakatoa came from a Tsunami. The deaths from Nevado Del Ruiz came from the lahars that were created. Deaths that came from Mt. Unzen in the past were influenced by a minor flank collapse that caused a tsunami.

For this, I’m taking into account the potential for lahars, slope collapse events, and other types of problems to affect areas of large population.

Eruptive Patterns

Simply put, certain volcanoes are more dangerous than others due to the fact that they are way more explosive. If a volcano has a history of creating large eruptions, it needs to be given more consideration as a potential problem than a small shield volcano would that only creates effusive eruptions.

Also, I am giving some consideration to the behavior of surrounding volcanoes. If a volcano lies in a region where every other volcano has undergone a flank collapse event, it would be prudent to consider that a flank collapse would be likely for that volcano as well.

Another consideration within eruptive patterns is the stage a volcano may be in. For example, a volcano that has undergone caldera collapse within the past 3000 years will likely be rebuilding for quite some time before it can undergo another caldera collapse event. While not all volcanoes behave in a perfectly cyclical manner, there is some elements of this in many volcanoes around the world. Certain elements such as an extremely large and steep edifice, or increasingly large explosive eruptions can be a red flag when looking for volcanoes that could be potential caldera or collapse eruptors.

Creating a Volcano Danger Tier List

When I started to compile this list, I realized that putting it as a ranking just didn’t make a ton of sense since it seems too cut and dry. We are not dealing with absolutes here, and this list will possibly change over the years.

All the volcanoes included in this list are very dangerous, but I’m separating them into four different tiers of high-danger.

Tier 1 – Inevitable Disaster

These volcanoes are the true ticking time bombs, where you know there will eventually be a major disaster, but you just can’t predict precisely when that disaster will occur.

Campi Flegrei (Italy): If you were to ask volcanologists around the world, most would point to the Naples bay region as one of the most dangerous volcanic regions in the world. Campi Flegrei specifically is a ticking time bomb, with many eruptions occurring over the last 10,000 years of varying size from within the caldera.

Campi Flegrei does not need to erupt in a large fashion to cause massive disaster, as there are densely populated regions that sit within the caldera itself. While a small eruption can cause a huge disaster in, Campi Flegrei has the potential to unleash very large eruptions as well. Considering the population of over 3 million people living within 30 kilometers and its propensity for frequent and sudden eruptions, there really is not much question that at some point in the future, we will be facing a very large disaster stemming from the Naples Region of Italy.

Taal (Philippines): Taal is a massive caldera volcano that has been highly active in the past 10,000 years. It sits within a rifting basin on the island of Luzon known as the Macolod corridor,  which has been a primary factor for Taal’s enormous size. Taal has featured eruptions of all sizes, including VEI-7 blasts in the distant Geological past, a VEI-6 eruption roughly 5500 years back, and many smaller eruptions as recent as 1977.

This isn’t really a surprising or complex choice to be included in the top tier of dangerous volcanoes. Taal is big, highly active, and can create very large eruptions. The biggest concern is the 2+ million people who live within 30 kilometers of the volcano, and the reasonably close location of the major city of Manila to Taal itself.  Taal is very well  monitored, but with the population density and the potential for it to go very big, there is a worry that even the best mitigation may not be able to prevent a catstrophe if a large eruption forms here.

Mayon (Philippines): Mayon is a member of the same country as Taal, but bears little resemblance. Mayon is a picturesque stratovolcano that forms a nearly perfect cone close to the eastern coast of the island of Luzon. Mayon has historically been a dangerous volcano, with numerous past eruptions claiming the lives of locals, with some eruptions killing more than 1200 people.

In modern times, a sizable population has built up around the Mayon Volcano, predominantly around the city of Legazpi. Mayon is a bit more of a speculative inclusion on this list as it hasn’t created an eruption larger than a vei-4 in its historical lifetime. While a VEI-4 would definitely cause problems here with the population density nearby, there is greater worry that it could potentially do something larger in the geologically near future.

Given its size and prominence, its activity level and increasing eruption size, and then also looking at the flank collapse history of all the nearby volcanoes, it can be speculated that Mayon could potentially be nearing a phase where it would either destroy its edifice via slope failure, or create a caldera forming eruption.

Aira Caldera (Japan): Many people are familiar with the Aira caldera for its highly active volcano SakuraJima. The Aira caldera is one of the five major caldera systems of Kyushu I wrote about a while back, and has the potential to do some very nasty things.

The biggest risk in the near future is a potential large eruption from the SakuraJima volcano. Despite its highly frequent eruptions, the Aira caldera and SakuraJima volcano have still been inflating, which indicates that the minor eruptions are not adequately relieving pressure build-up.

There is worry that another eruption similar or larger than the 1914 eruption could occur with inflation levels approaching the levels prior to that eruption, and that would likely cause a lot of major problems with the nearby population in cities such as Kagoshima, Tarumizu, and others. Beyond the “normal” eruption scenario, there is a major risk of water-interaction here which would likely act as a catalyst for any potential eruption here.

Finally, outside just Sakurajima itself, the caldera of Aira itself is of concern having had large eruptions multiple times in the past, including a VEI-6 blast and numerous maar forming eruptions that would devastate communities if they were to occur in modern times.

Apoyeque: With a history of increasingly large explosive eruptions, a large nearby city, and a strong potential for magma-water interaction creating major problems, Apoyeque deserves way more attention than it gets.More specifically, the city of Managua, which is surrounded by caldera volcanoes,  a lake, and features many explosive maars within the city limits it a disaster waiting to happen. Managua itself already has dealt with many devastating earthquakes, but a VEI-6 eruption like the one Apoyeque had around 50 B.C. would be on a completely different scale.

Tier 2 – High Potential for a Potential Megadisaster

Tier 2 is reserved for volcanoes that still have a ton of potential to form a megadisaster, but aren’t quite as much of a sure thing. These volcanoes may have a chance of escaping a disaster scenario with proper mitigation, or may escape it simply by virtue of the volcano remaining silent or weaker in  nature. Explanations and analysis to come later, stay tuned.

Tier 3 –  Has The Ingredients for a Potential Disaster with More Uncertainty

Tier 3 is more of a watch list of volcanoes that have a large population nearby and a lot of uncertainty around them. These volcanoes can all turn into major potential disasters, but there are some elements that cast doubt as to whether that type of scenario would unfold.

Tier 4 – Possible Scenario for a Large Scale Disaster, Although Not Likely

Tier 4 includes volcanoes that you can see a possibility for a large scale disaster, but the likelihood of that arriving isn’t all that high in the geologically near future.

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