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Volcano eruption: what to do

A volcano can send out ash, hot gas, lava, and mudflows. This page helps you leave early, protect yourself from ash, and avoid the valleys where mudflows travel.

Do this now

  1. Follow evacuation orders from local officials, and leave early. Do not wait to see the eruption.
  2. Stay out of river valleys and low areas that lead down from the volcano.
  3. If ash is falling, go indoors, close doors and windows, and cover vents.
  4. If you must go outside, wear a well fitting N95 or similar mask, and protect your eyes.
  5. Listen to local officials by radio or phone alerts for updates.

Follow evacuation orders

Officials decide who must leave, based on the volcano's activity and the paths that ash and flows could take. If you are told to go, go early, while roads are open and clear.

Take your emergency kit, medicines, pets, and important papers. Avoid areas downwind of the volcano, where ash falls, and river valleys downstream. Know your route and a place to meet, and sign up for any volcano alert service run by your national geological agency or local emergency office (the US Geological Survey runs one in the United States).

Ash fall protection

Volcanic ash is made of tiny pieces of rock and glass. It can irritate eyes, skin, and lungs, and it can be slippery and heavy. Ash can travel hundreds of miles on the wind.

  • Limit your time outdoors.
  • Wear a well fitting, certified mask such as an N95. A damp cloth over your nose and mouth is a last resort.
  • Wear glasses or goggles rather than contact lenses, and keep your skin covered.
  • Keep your doors and windows closed, and seal gaps if you are staying in.
  • Bring pets indoors, and keep animals and food covered.

People with asthma, lung disease, or heart disease should be especially careful and stay indoors if they can.

Stay off the roof

Do not climb onto your roof to clear ash unless you have training and guidance. Wet ash is heavy and can overload a roof, and it makes surfaces very slippery.

Driving in ash

Avoid driving in heavy ash. It cuts visibility, clogs engines, and makes roads slippery.

If you must drive, keep your windows up, turn off the air conditioning, and go slowly. Do not drive if officials ask people to stay off the roads.

Lahars and valleys

A lahar is a fast flowing mixture of volcanic debris and water, like a river of wet concrete. It can come down river valleys far from the volcano, and it can happen with little warning.

If you are on a valley floor and a lahar is coming, climb to high ground, such as a hillside, as quickly as you can, and then stay there. Do not try to outrun it along the valley. In areas without alert systems, a rumbling ground and a roar like a jet or a train is a sign to go uphill at once.

Valleys can be cut off

Your route to safety may be blocked by mudflows. If lahars are a threat, stay off valley floors and out of low areas.

Gas and other hazards

Volcanoes release gases that can build up in low places. Avoid craters and low spots near the volcano, and do not go near an erupting volcano to look.

Lava and hot debris can move quickly. Stay far away, and obey all closures and warnings.

After the eruption

Stay put or stay away until officials say it is safe. Ash can stay in the air and fall for days. Check on neighbors who may need help with masks or supplies.

When you clean up, wear a mask and goggles, and wet ash lightly before sweeping to keep dust down. Keep ash out of drains.