Volcanic Eruption

Mexico

In an eruption, what kills is almost never the lava. It's lahars — rivers of mud and rock that race down valleys tens of kilometers from the crater — and pyroclastic flows, which cannot be outrun. And what wrecks daily life for weeks afterward is the ash. This guide covers all three, and why the only real defense against the first two is knowing in advance whether you live in their path.

Updated on September 11, 2026

Columna eruptiva del volcán Mount St. Helens el 18 de mayo de 1980, vista desde el aire.
Columna eruptiva del volcán Mount St. Helens el 18 de mayo de 1980, vista desde el aire.USGS Volcano Hazards Program · Dominio público

Before the crisis

  1. Find the hazard map for your volcano. The USGS lists this as step one: "review hazard maps to understand your exposure, plan evacuation routes, and prepare your home or business in advance." Those maps are published by your country's volcano observatory. Look at it once, calmly, and locate your house, your school, and your workplace on it. That's half an hour you won't have on eruption day.
  2. Learn where your high ground is, in meters of elevation. Against a lahar you don't run forward, you climb. The USGS gives the figure: know the quickest route to high ground, at least 30 meters (100 ft) above the valley floor. That's not 30 meters of distance — it's 30 meters of elevation above the channel. Walk it once so you know how long it takes.
  3. Prepare your home for ash — the one thing that's certain. Ash travels much farther and much more often than any other hazard. IVHHN recommends keeping on hand masks and eye protection, a battery radio, flashlights, medication, and cleaning supplies, plus water for at least 72 hours: one gallon (3-4 liters) per person per day, along with non-perishable food for the same period, pets included.
  4. Disconnect your gutters before it falls. This is the most specific piece of advice, and the one almost nobody knows: IVHHN recommends disconnecting gutter downspouts and disconnecting rainwater collection systems before ashfall begins. Otherwise the ash clogs them and contaminates your tank.
  5. Agree on a meeting point outside the valley. If the family is scattered between home, school, and work, the meeting point needs to be outside the channel and up high. And an out-of-town contact everyone calls: when the local network gets overloaded, a long-distance call sometimes still gets through.
Official sources for this section

During the crisis

  1. If evacuation is ordered, leave now. With volcanoes, the gap between the order and the event can be minutes.
  2. Stay away from river channels. The USGS: "avoid river channels during heavy rain or volcanic activity." A lahar can arrive without any explosion you've heard.
  3. If ash is falling, get indoors. Close doors and windows, put damp towels along door gaps, and tape drafty windows (IVHHN).
  4. Don't drive if you can avoid it. Ash cuts visibility to almost nothing and damages engines. If you must, go slowly with your lights on.
  5. Protect your eyes. Volcanic ash is ground glass and rock: it scratches the cornea. Wear closed goggles, and skip contact lenses.
  6. Keep pets indoors. If pets go out, brush them before letting them indoors (IVHHN).
Children — this one matters
IVHHN is explicit about something few people know: "Unfortunately respirators are not made to fit children's faces. For this reason, children must be kept indoors and stopped from playing in dusty environments whilst ash is present." There is no children's mask that truly protects: a child's protection is the inside of the house.
If you have a beard
Another IVHHN fact that changes what you should do: a respirator's fit depends on contact with smooth skin, so "a good fit relies on close contact between the respirator and smooth skin without hair in the region of the seal. Consequently a beard or beard stubble can affect the fit and reduce protection." If you'll be working in an ashy environment, shave the seal area.
People with asthma, COPD, or heart disease
Fine ash is the main respiratory hazard. Stay inside, with the house sealed, and keep rescue medication within reach and in view, not in a drawer. If shortness of breath doesn't ease with your usual medication, seek medical care.
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After the crisis

  • Wear a harness when clearing the roof. This is IVHHN's explicit recommendation: ash makes the surface slippery and hides the edge.
  • Don't soak the ash to remove it. IVHHN warns that over-wetting it increases the weight and the risk of collapse. A little water so it doesn't fly around, not an open hose.
  • If water became contaminated with ash, IVHHN says to let it settle and then use the clear water on top. Avoid dishwashers and washing machines while contamination is heavy: ash is abrasive and destroys pumps.
  • Change your vehicle's oil and filters much more often — IVHHN mentions every 50 to 100 miles (80-160 km) in very dusty conditions — and clean brakes and the alternator with compressed air.
  • Secure clean food and water for livestock, which is usually where the economic loss begins in rural areas.
  • Don't dry-sweep indoors. It just kicks the fine dust you removed back into the air; dampen lightly and collect it instead.

And the warning that still holds once it all seems over: as long as loose material remains on the slopes, every heavy rain can generate a new lahar. The USGS says it plainly — avoid river channels during heavy rain or volcanic activity — and that rule holds for months after the eruption, not days.

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Family plan

A family plan is not a pretty document: it is a handful of agreements made today, while everyone is calm, so you do not have to decide with your heart racing and no signal on your phone. It takes one conversation over the table and fits on a sheet of paper stuck to the refrigerator.

  1. Decide where to meet, in two different places. One near home, for getting out quickly, and another outside the neighborhood, in case you cannot get back to the area. Everyone should know both by heart, children included, and it should not depend on anyone having a phone handy.
  2. Name an out-of-area contact. One person in another city that everyone texts when they can. That person gathers information and passes it along, so no one has to go out looking for anyone else. It works because local lines get overloaded first, and because a text gets through where a call does not.
  3. Assign responsibilities to specific people. Who grabs the emergency bag, who shuts off the gas and power, who helps the older person or someone with reduced mobility, who gets the pets out. A task with no owner is a task no one does.
  4. Keep the list on paper. Phone numbers for family, the out-of-area contact, the doctor, the school, insurance, and emergency services. On paper, in the emergency bag, and in your wallet. A phone with a dead battery has no address book.
  5. Practice it once. A fifteen-minute drill reveals what the conversation does not: that the emergency bag was buried in the closet, that no one knows where the gas shutoff is, that the child does not remember the meeting point. Repeat it at least once a year and whenever something important at home changes.
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Food and water

How to store it so it works when you need it
The CDC calls for approved food-grade containers with a tight-fitting lid, made of a sturdy, unbreakable material —never glass— and with a narrow mouth for pouring. An explicit warning: never use a container that has held toxic chemicals such as bleach or pesticides. And what almost everyone forgets: stored water should be replaced every 6 months. To disinfect the container before filling it, use a teaspoon of unscented household bleach per liter of water, wait 30 seconds, and pour it out.
What food to keep on hand
Ready.gov recommends several days of non-perishable food and gives a concrete list: ready-to-eat canned meats, fruits, and vegetables —and a can opener—, protein or fruit bars, dry cereal or granola, peanut butter, dried fruit, canned juices, and pasteurized long-life milk. The rule when putting it together is simple: food your family will actually eat, that needs no cooking, and that you can rotate before it expires.
  • Keep the refrigerator and freezer closed: every time you open one, you waste hours of stored cold.
  • Throw out any food that has touched floodwater, even if the container looks intact. This is an explicit Ready.gov instruction.
  • Keep a manual can opener. It is the item people forget most, and without it your pantry is useless.
  • If you buy bottled water, keep it sealed in its original container, in a cool, dark place.
Official sources for this section

Power and communications

When the cell network is overloaded: text, do not call
The joint FCC and FEMA guide explains why: "text messages may get through when your call does not", even if delivery is delayed when the network is congested. And it asks for something almost no one does: "limit non-emergency calls", because every call takes up space that emergency communications need. Also save a contact under the name "ICE" (In Case of Emergency), the convention rescue personnel look for on someone else's phone.
How to stretch your battery
The same guide recommends lowering screen brightness and turning off apps to conserve charge. In an emergency your phone stops being entertainment and becomes your only line to the outside world: treat it like your water supply.
The battery-powered radio is still irreplaceable
The FCC and FEMA recommend a battery-powered radio or a portable television to follow emergency bulletins during power outages. It is the only channel that depends on neither your electricity nor the cell network.
The alerts you already have and did not know about
In the United States, Wireless Emergency Alerts are free messages that go straight to your phone for severe weather, AMBER alerts, and threats to safety in your area. Two things worth knowing: you do not need to sign up —phones have supported them since 2012— and they are not affected by network congestion, so they get through when calls no longer do. Find out what the equivalent system is in your country, and do not mute it.
  • Have at least one light source that does not depend on the grid: a battery-powered or hand-crank flashlight, or a rechargeable lamp.
  • Charge phones and backup batteries before the forecast event arrives, not after the power is already out.
  • Keep a list of important phone numbers on paper: if your phone dies, your contacts die with it.
  • Agree with your family that after an emergency everyone texts the same contact instead of calling each other.
Official sources for this section

Health and special needs

This is the section that decides who has a hard time and who has a dangerously hard time. An emergency does not suspend diabetes, high blood pressure, pregnancy, or dependence on an oxygen concentrator: what gets cut off is access to the pharmacy, the clinic, and electricity. Everything that follows needs to be prepared beforehand, because once the emergency hits, there is no more room.

  1. Keep a reserve of your medications, and know which ones hold up. Ready.gov calls for a several-day supply of prescription medications. For those that need refrigeration, the CDC is blunt: once the power has been out for a day or more, discard any medication that requires refrigeration, unless its label says otherwise.
  2. The insulin exception, worth knowing word for word. The FDA documents that insulin in the manufacturer's original vials or cartridges —opened or unopened— can stay unrefrigerated between 15 and 30 °C (59 and 86 °F) for up to 28 days and still work. It loses effectiveness at extreme temperatures, and the longer the exposure, the less effective it becomes. In an emergency "you may still need to use insulin that was stored above 30 °C" —that is better than not using it at all— but as soon as proper storage is available again, those vials should be discarded and replaced.
  3. If someone depends on electric medical equipment, there is one step almost no one takes. Ready.gov says it explicitly: you can ask your power company to put you on a priority list for service restoration. That step is free, can be done on any ordinary day, and changes the order in which you get reconnected. Add a backup battery for an electric wheelchair and for any assistive device, and talk with your doctor about how to keep the equipment running during a power outage.
  4. Keep a copy of medical information, not just the pills. A list of medications with dosages, allergies, diagnoses, doctors' contact information, and —for infants— the vaccination record. A prescription bottle cannot always be refilled at a pharmacy in another city; a written list can solve that.
Pregnancy and newborns
The CDC calls for prenatal vitamins and other medications in the kit, plus supplies in case delivery happens without being able to reach a hospital: clean towels, clean sharp scissors, a bulb syringe, gloves, two clean white shoelaces to tie the cord, clean sheets, sanitary pads, soap or alcohol, and garbage bags. For infants: diapers, wipes, ointment, bottles, and formula. One detail that matters: ready-to-feed formula is the safest option in an emergency, because it does not need to be mixed with water and comes in sterile, single-use containers.
Disability, reduced mobility, and older adults
Ready.gov stresses planning accessible transportation in advance for evacuating or getting around, and including a service or support animal with its food, water, and supplies. That plan should be worked out with specific, named neighbors, not left vague.
The blow that comes later: mental health
The CDC names the normal reactions after a disaster —fear, anger, sadness, worry, numbness, frustration, trouble sleeping, or nightmares— and recommends taking care of your body, staying in touch with other people, and taking breaks from the news. In the United States and its territories, the Disaster Distress Helpline is available 24 hours a day: 1-800-985-5990, with service in Spanish. Asking for help here is not weakness: it is part of recovery, just like repairing the roof.
Official sources for this section

Home and belongings

  1. Before you go back in: look, smell, and listen from outside. The CDC lays it out this way: if you smell gas or suspect a leak, shut off the main valve, open all the windows, and get out immediately. If there is standing water inside and you can cut the power from a dry spot, do it. And one simple warning that prevents explosions and fires: use battery-powered flashlights, not candles, gas lanterns, or torches.
  2. Ventilate before you settle in. The CDC recommends going in briefly to open doors and windows, and letting the house air out for at least 30 minutes before staying inside.
  3. Shutting off utilities: when to do it, and the mistake you cannot make. Gas has a rule with no exceptions: if you shut it off for any reason, only a qualified professional can turn it back on. Never turn it back on yourself. Electricity is shut off by switching off the individual circuits first and the main breaker last —the order matters, because an electrical spark can ignite gas if there is a leak—. Water should be shut off if pipes may have cracked, because that contaminates the house supply, and should not be turned back on until authorities confirm it is safe to drink.
  4. Go back only when authorities say it is safe. It sounds obvious, and it is the instruction people break most often: go back home only when authorities say it is safe. Structural damage is not always visible from the street.
  • Make a photo inventory of what is in each room today: it takes twenty minutes and is worth its weight in gold for a claim.
  • Keep that inventory and your policies outside the house —in the cloud or with a family member— because a file that gets soaked along with the house is useless.
  • If you have to leave, take your documents with you, not your furniture.
  • Do not sign anything with a contractor while you are in shock: check the money section for the warning signs of fraud.
Official sources for this section

Money and income

The documents you need to protect today
The official recommendation is to keep insurance policies, deeds, property records, and other important papers in a safe place outside the house. FEMA publishes the Emergency Financial First Aid Kit for this, organized into four sections: household identification, financial and legal documentation, medical information, and contacts. Its rule for paper: a fireproof and waterproof box or safe, a bank safe-deposit box, or in the hands of someone you trust. For digital files: password-protected files on an external drive or in secure storage outside the home. And if you pay everything online, print your account records periodically.
An emergency fund, even a small one
The CFPB avoids magic formulas: "the amount you need depends on your situation", but "even a small amount can provide some financial security". Its underlying argument is the one that matters: without that cushion, a single unexpected expense can grow far larger than the original bill through interest and fees, because it forces you to rely on credit.
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Economic opportunities

Adaptation and income
Time to start: Days

Debris hauling and furniture moving

Taking debris, ruined furniture and damaged appliances to the collection point set by the city, or moving belongings somewhere dry, is one of the first needs and one few can meet without a vehicle.

Estimated investment: USD 0–200 Difficulty: baja Vehicle needed Tools needed
Time to start: Days

Home-cooked food delivered

When many households are left without a kitchen, without gas or without time, affordable ready meals become a basic neighbourhood service.

Estimated investment: USD 20–300 Difficulty: baja From home
Time to start: Days

Errands and home delivery

Older, ill or car-less people need someone to bring medicine, groceries and water. Charged per trip or per hour.

Estimated investment: USD 0–150 Difficulty: baja Vehicle needed
Time to start: Days

Paperwork and digital assistance

Replacing soaked or lost documents, filling in online forms, scanning and printing. Many people cannot do it alone and are glad to pay for help.

Estimated investment: USD 0–250 Difficulty: baja From home
Time to start: Days

Clearing fallen branches and trees

After high winds, yards, pavements and driveways are blocked. Cutting, sectioning and hauling away is among the first things hired.

Estimated investment: USD 60–600 Difficulty: media Vehicle needed Tools needed
Time to start: Days

Selling rechargeable lamps, batteries and power banks

When the power is out for days, battery lamps, batteries and phone power banks sell out first. Local resale with a small margin and fast turnover.

Estimated investment: USD 50–600 Difficulty: baja From home
Time to start: Days

Volcanic ash removal from roofs, terraces and yards

After ashfall it has to be removed quickly: IVHHN notes that a roof is dangerously overloaded at about 10 cm of wet ash. Demand is concentrated and the fall risk is real, so it only makes sense as a service with a harness, non-slip footwear, an N95 mask, sealed goggles and never working alone.

Estimated investment: USD 50–400 Difficulty: media Vehicle needed Tools needed
Time to start: Days

Filter changes and vehicle cleaning after ashfall

Volcanic ash is abrasive rock and it ruins engines. After ashfall IVHHN recommends changing oil and air filters far more often than usual, cleaning brakes and the alternator, and rinsing with water. It is a simple, high-volume service that people actively look for in the following weeks.

Estimated investment: USD 100–600 Difficulty: media Tools needed

These are possibilities, not guarantees. Results depend on location, demand, competition, capital, skills and each person’s circumstances.

Filter the income possibilities by your situation. Results are starting points to research locally, not personalised advice. What can I do?

What you can sell

Adaptation and income

Volcanic ash creates a very particular kind of demand: it doesn't destroy all at once like an earthquake, it accumulates. And as long as it keeps falling, the same work has to be repeated, which turns several of these services into recurring income rather than a one-time job.

  • Ash removal from roofs, which is the urgent one: wet ash weighs far more and can collapse a light roof.
  • Cleaning of gutters, rooftop tanks, and cisterns, because ash contaminates stored water and clogs drains.
  • Car washing and air-filter changes: ash is abrasive and ruins engines and paint.
  • N-95 masks, goggles, and plastic covers to protect electronics and furniture.
  • Temporary sealing of windows and gaps with tape and plastic, house by house.
  • Cleaning of solar panels and air-conditioning units, which lose efficiency when coated in ash.
Official sources for this section

Businesses and self-employment

Adaptation and income

It helps to start with one figure to size up what we're talking about: according to the ILO, informality affects nearly half of the employed population of Latin America and the Caribbean, around 47%, with huge differences between countries — under 30% in Uruguay and Chile, over 70% in Bolivia and Peru. For millions of families in the region, "looking for a job" and "starting something on your own" are the same sentence. What follows is not a promise of income: it is a map of what people actually do when a crisis hits, with the requirements and the risks laid out plainly.

Roof ash removal — the most requested service, and the most delicate
You need a stable ladder, plastic or wooden shovels (metal ones damage roofing), sacks, N-95 respiratory protection, and a harness if the roof has a pitch. Two warnings you need to tell the client and follow yourself: never clear a wet roof or one with ash still actively falling, and falls from height are among the risks OSHA most often documents in recovery work. Charge by square footage and by thickness, not by "the whole roof."
Vehicle filters and car washing
With a pressure washer, air filters for the area's most common models, and a space with drainage, you can meet demand that repeats with every ash fall. The key to the business is inventory: having the filter the customer needs today is worth more than doing a spotless wash next week.
Respiratory-protection supply
Selling legitimate N-95 masks — not cloth face coverings, which don't filter fine particles — is a public-health service as much as a business. Buy from an identifiable distributor, keep the invoice, and don't promise protection the product doesn't give. Reputation is the asset here: whoever sold fake masks during the emergency doesn't sell anything else in their neighborhood again.
United States — SBA disaster loans
For areas with a declared disaster. The Economic Injury Disaster Loan (EIDL) provides working capital for affected small businesses and nonprofit organizations; the physical damage loan covers losses not covered by insurance. Combined cap of $2 million, interest not exceeding 4% if you cannot obtain credit elsewhere, terms of up to 30 years, and the first payment deferred 12 months. There is also a line for homeowners (up to $500,000) and for renters for personal property (up to $100,000).
Mexico — what actually exists today
FONDEN stopped taking on new commitments on January 1, 2021. What operates today in emergencies is PAEAN, run by Civil Protection, and it is worth knowing exactly what it is and is not: it delivers relief supplies — food kits, water, blankets, roofing sheets, cleaning materials — when a state's own capacity is overwhelmed. It is not a reconstruction fund or a loan for your business. For capital, look at state, municipal, or development-bank programs, always verifying on the official website: fraud schemes that use its name circulate around these programs.
Brazil — Pronampe for micro and small businesses
A credit line for microenterprises (annual revenue up to 360,000 reais) and small businesses (from 360,000 to 4.8 million). The amount can reach up to 60% of the previous year's gross revenue for businesses with more than one year in operation, and up to 50% for new ones. The maximum rate is the SELIC rate plus up to 6% per year.
Official sources for this section

Products and tools

Products and tools that could be useful

An orientation list to complement the information on this page. This is not a shop, and nothing here is a required purchase.

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Manuals and tutorials

PDF · manual

Manual de qué hacer: Erupción Volcánica

Guía completa en PDF para imprimir o llevar en el teléfono, con las medidas oficiales antes, durante y después, y las fuentes citadas.

PDF · manual

What-to-do manual: Volcanic Eruption

Complete PDF guide to print or carry on your phone, with official measures before, during and after, and cited sources.

Checklists and templates

Downloadable materials for this section are not published yet.

Recovery stories

Real, published and verifiable cases: each one links to the source where it was documented. No made-up testimonials here.

La Palma farmers after the Cumbre Vieja eruption — pull up and replant

The eruption lasted 85 days and left 370 hectares of farmland affected. Federico Simón Rodríguez, of the Tamanca winery, had 65% of his production covered in ash. Airam Gutiérrez made a different call than waiting it out: he pulled up the damaged crops to plant in summer, counting on a harvest the following year plus three or four more months of picking. Juan Vicente Rodríguez, of a local cooperative, replanted the five fanegadas he could still access.

What to learn from this: With ash on top, waiting to see if the plant recovers usually costs more than pulling it up and replanting. And you need to count the real timeline — planting, harvest, picking — before taking out a loan, so you don't take on debt at a term that doesn't match your income.

eldiario.es · Canarias Ahora · 2022-04-01 · Volver a sembrar tres meses después del final de la erupción del volcán de La Palma

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