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

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.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 is not fluffy**





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







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





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



Volcanologist



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 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 tellwhat an eruption is going to do, how big it will be, orwhen 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? 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:

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"





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).

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.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: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 p reexisting 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:No.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.