Volcanic ash is not fluffy & volcanoes don't smoke! Setting the story straight & how to protect yourself.

Mount St. Helens, May 18, 1980.
Top information resources for volcanic ash:
USGS Volcanic Ash Impacts and Mitigation

The International Volcanic Health Hazard Network 

GNS Be Prepared: Volcanic Ashfall

Global Volcanic Hazards and Risk 

List of Volcano Observatories

Items to stock before ashfall

As you read this, there are likely around 20 volcanoes actively erupting right now. There are over 40 ongoing eruptions around the world. There are 1,431 volcanoes that we consider to be potentially active, or that erupted recently enough to be able to erupt any time soon (list here), and there are hundreds of millions of people living around those volcanoes. On top of that, there are many people who travel to or near volcanoes, and even more who fly around the world in planes that can be impacted by volcanic ash. Freight planes and ships can be halted and economies are impacted. As you see in this first video that was taken at Mount St. Helens on May 18, 1980, volcanic ashfall can be a frightening experience.

"whoever finds this... I don't know... At this moment, I honest to God think I'm dead... It burns to breathe"

So, volcanic ash is kind of a big deal.

In this blog post I am going to take you through some common misunderstandings, frequently asked questions, and provide a bunch of resources that I trust as links along the way.

"It went black. It was all pervasive. It was never ending"

Do you know what to do if you are in an area impacted by an eruption? If the answer is no, and you find yourself near an eruption, things will be much more stressful. Cell services can go down and you could be left not knowing what to do. Many volcanoes give us warning signs and volcano observatories will give you information about what they are and what they mean. When you travel to a volcano, it is important to know how and where to get that information. This is especially important in the age of rampant misinformation spreading at lightning speed on social media and in online tabloids.

Far too often I see headlines talking about smoking volcanoes. Not just headlines, but everywhere I see this misconception.
**Volcanoes do not smoke** 

Why do I even care? Because the hazards are very different. While smoke (a product of combustion or pyrolysis) has its own health hazards, smoke cannot collapse a roof because its own weight. Smoke cannot bring down powerlines. Smoke can't clog up important water ways. Smoke doesn't completely bury farmland in inches- to feet-deep of rock. Smoke can't result in deadly lahars (volcanic mudflows). Flying a plane through volcanic ash has different dangers - volcanic ash can shut down engines!

Volcanic ash that was erupted from Augustine volcano in Alaska. Courtesy of AVO. More here

Volcanic ash can impact you even if you live nowhere near a volcano. It can cross states, countries, continents, and oceans during larger eruptions. Air travel can be halted for very good safety reasons.

**Volcanic ash is not fluffy**

In movies, volcanic ash is this odd light grey fluffy stuff. This is not the case. Dante's Peak apparently used wet newspaper for the ash. The real stuff is very different.

That grey/brown/sometimes pink plume you see coming out of a volcano is fragmented rock, glass, and crystals. This stuff is heavy and abrasive. Think of shoveling an entire beach of sand if the eruption dumps enough ash onto your town. This is much heavier than shoveling snow. Fresh snow is 50-70 km/m3, older compressed snow is 200-500 km/m3, glacial ice is 830-917 kg/m3 (more). Check out the densities of the different components of volcanic ash:

Density of individual ash particles, kg/m3, from Shipley and Sarna-Wojcicki, 1982. From here.
Type of ash particle                    Density of particle 
Pumice fragments                       700-1,200 kg/m3
Volcanic glass shards                  2,350-2450 kg/m3
Crystals and minerals                  2,700-3,300 kg/m3 
Other rock fragments                  2,600-3,200 kg/m3 

Volcanic ash: What is it and where does it go, and for how long?

Volcanic ash was once magma. It was violently blown apart during a volcanic eruption as gases within the magma rapidly expand and burst, like shaking a bottle of soda and taking the cap off. The magma quenches to solid bits of rock, glass, and what ever crystals were already in the magma. 'Ash' is the term used for particles less than 2 mm in size. In the images of Augustine ash above and the USGS SEM image of ash to the left, you can see round pockets within the ash particles - those are the gas bubbles that were expanding leading to, and during the eruption.

The video below shows a volcanic ash plume coming out right at the vent. This hot mass of rock, glass, crystals, and gases have traveled as magma from many kilometers below the surface. It's pretty incredible.

Volcanic ash can sometimes be a very far-reaching product. The ash from the 2011 Puyehue-Cordón Caulle eruption in Chile caused flight cancellations across Australia and New Zealand! Ash plumes can reach a few tens of kilometers vertically (usually less than a few kilometers) then they go with the [atmospheric] flow. Ash plumes don't care about political boundaries, they don't care about the shape of the land like pyroclastic flows and lahars do, they just follow the wind direction (very large ash plumes can also travel upwind for a while). So it depends on the size and style of eruption, and the wind speed and direction. Luckily for us, smaller eruptions are much, much more common than larger eruptions. But larger eruptions do happen, and they do impact people.

Volcanic eruptions can last hours, days, months, or even years. The Calbuco eruption in the video above produced a few impressive ash plumes on the scale of days, yet volcanoes like Sinabung, Sakurajuma, Colima, Popocatepetl, and more, produce smaller ash plumes over the course of years or even decades. It all depends on the magma supply - how much magma keeps coming up to the surface.

We cannot tell exactly what an eruption is going to do, how big it will be, or specifically when it will happen, and we cannot tell how long an eruption will last. But we can understand what scenarios might take place at a specific volcano and we can help communities prepare. We can give eruption forecasts warning that an eruption might be, or is, on its way. We can even tell you what areas might be impacted by the different eruption hazards and what those impacts might be like. All of this takes a lot of intricate science and it does saves lives.

Volcanologist Erik Klemetti wrote about how long it takes for ash to settle out of the atmosphere here: What happens to all that volcanic ash?

How often do volcanic ash plumes occur?

As we now know, volcanoes are always erupting (but no, activity is not increasing). We live on a very active planet. When will an ash plume travel near you? This depends on where you are. Here are two examples:
- Estimating the frequency of volcanic ash clouds over northern Europe
- The frequency of explosive volcanic eruptions in Southeast Asia

Heavy ashfall from explosive eruptions from Galunggung volcano damaged or destroyed hundreds of houses, including these in a village near Kadong. The eruptions forced evacuation of 62,000 people living in densely populated areas near the volcano. Photo by Jack Lockwood, 1982 (U.S. Geological Survey).

How can volcanic ash impact you and how do you protect yourself?

This video shows what it can be like living with volcanic ash:

"First I felt it in my eyes, they hurt"... "On our tongue it felt like we were eating sand"

Just breathing in a bit of volcanic ash is not going to kill you, pre-existing medical conditions aside. The impacts depend on how fine the ash particles are, how much you are exposed to, and for how long. There is no need to be afraid (pyroclastic flows and other more dangerous processes aside...), a bit of knowledge and preparation can make a huge difference. The mother of all resources for volcanic ash health and safety is this website: The International Volcanic Health Hazard Network (IVHHN).

While inhaling small amounts of ash won't be hazardous to most people, enough fine ash can be nasty for your airways, particularly for people with preexisting conditions like asthma. Ash can also make driving conditions hazardous as small amounts can make roads slick. The best advice is to just stay out of the ash if you can and try to keep it out of your home. I acknowledge that this can be unrealistic, like during long-lived eruptions or people who live in homes that don't have sealed windows.

When you are in volcanic ashfall, wear a facemask (N-95 is recommended). The key resources for health are 'The Health Hazards of Volcanic Ash - A Guide for the Public' pamphlet, and the 'Guidelines on Preparedness Before, During, and After an eruption' pamphlet. You can download these, print them out, and take them with you when you travel.

There is even a video to show you how to fit a face mask properly:

Have you ever had dust blown into your eyes? It's hard to function with your eye slamming shut and tears streaming down your face. So it is important to keep ash out of your eyes. Eye symptoms are listed here. I saw some pretty neat kids goggles (like you wear swimming) during the Agung crisis, and you can usually get eye protection from a hardware store. There is no specific recommendation, but make sure it won't let anything from the outside in to your eyes. If you wear contacts, take them out and pop your glasses on. You don't want ash behind your contact lenses. Ash can scratch surfaces so careful wiping it off glasses or windscreens. I wash it off glasses with water, not a cloth, to prevent the world looking foggy until I can get new lenses that aren't completely scratched. Trust me, that sucks.

Volcanic ash is bad for your animals too!

You should always have a plan for your pets for your local hazards. You can get information on that here:

For farm animals head over to the USGS site here. This also includes information for agricultural plants (pastures, forestry, crops).

Is that ash plume going to reverse climate change/plunge us into an ice age/KILL US ALL???


It takes a large enough eruption to impact climate at all. Enough gases need to get high enough into the atmosphere, and there are other factors like the location of the volcano and season. Volcanoes are erupting all the time. It is relatively rare that they impact climate. When they do, it is usually up to a few years.

While we're at it: "All studies to date of global volcanic carbon dioxide emissions indicate that present-day subaerial and submarine volcanoes release less than a percent of the carbon dioxide released currently by human activities." More here.

So you have a whole lot of ash, now what do you do with it?

This video shows what it was like cleaning up the ash after the 2015 Calbuco eruption:

We have established that this stuff is heavy. You can have many inches of it deposited during larger eruption and you will need to get rid of it. This USGS site tells you how to prepare and about cleaning up for households. There are also tabs for businesses and communities.

Clean-up advice is given on the GNS Be Prepared website and you can get more details at the USGS site.
Table of increasing ashfall depth discussing impacts and scale of clean up efforts by USGS.

Where can you get trustworthy updates?
Beware of dramatic tabloid headlines. Tabloids are notoriously bad for fear-mongering and incorporating false information during a volcanic crisis. Watch out for headlines with words in all caps and be very wary of anything with overly dramatic language like "SPEWING SMOKE'. While many media outlets do incredible work presenting the facts, there are people out there being paid to lie to you with clickbait. Always check anything with official and trusted sources.

The first places to go are the local Volcano Observatory, monitoring agency, or disaster agency. A list of volcano observatories can be found here. For example, in Indonesia CVGHM is the volcano agency, and BNPB is the disaster agency. Both will provide information. They also both have Twitter and Facebook accounts. I have a list of official volcanology agency Twitter accounts here.

Volcanic ash advisories are given by Volcanic Ash Aviation Centers (VAACs) around the world. These will give the height and distribution of ash plumes, keeping in mind that ash plumes can go in completely different directions at different altitudes. There is a handy guide on how to read these advisories here.

If you are a traveler, your flights may be delayed or cancelled to avoid volcanic ash. This is for good reason (see this video). Volcanic ash can cause plane engines to fail and make windscreens opaque. You don't want to feel the sudden rush of your plane plunging towards the ground (we monitor volcanoes to prevent this). In this case, contact your travel insurance agency, your airline, and keep an eye on information releases from your local airport.

If you are faced with a potential eruption, be critical about what you read and go to trusted sources that I have listed above. Listen to your local official agencies above all else. People live with eruptions around the world and we know a lot about how to stay safe. With some thought and a few actions, you can enjoy the beautiful volcanic landscapes and communities that we are fortunate to have around the world.

This blog post is barely scraping the surface of all we know about volcanic ash and the impacts. You can find more papers on different aspects of ash here and there is much more information and research out there.

Note: none of this research has been done by me. It is the product of hard-working researchers around the world. There are groups out there researching volcanic ash (or tephra) like the International Focus Group on Tephrochronology, and the groups working to create the links through this page. This includes studying the properties of the ash (shape, components, etc), how far the ash goes (studying the deposits and making numerical models), and how it affects people, animals, plants, and infrastructure.

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