A volcano is a vent in the Earth’s crust that allows molten rock, gases, and debris to escape to the surface. Over time, accumulation of these erupted products creates a volcanic mountain. A volcanic eruption may involve lava and other debris that can flow up to 100 mph, destroying everything in their path. Volcanic ash can travel 100s of miles and cause severe health problems. A volcanic eruption can:

  • Contaminate water supplies
  • Damage machinery
  • Reduce visibility through smog and harmful gases that may threaten low lying areas
  • Make it hard to breathe and irritate the skin, eyes, nose, and throat

Nearby Volcanoes

Washington state has five major volcanoes - Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens and Mount Adams.


Volcanoes may lie dormant for many years, but research and past activity shows that these volcanoes will erupt again. 

Before an Eruption

  • Know your risk from an eruption.
  • Learn about community warning systems.
  • Get necessary supplies in advance.
  • Consult a doctor if you have existing respiratory difficulties.
  • Practice a communication and evacuation plan with everyone in your family.
  • Have a shelter in place plan if your biggest risk is ash.
  • Find out if your homeowners insurance will cover a volcanic eruption.

During an Eruption

  • Listen to alerts.
  • Follow evacuation or shelter in place orders.
  • Avoid areas downwind and downstream of the volcano.
  • Take shelter from volcanic ash where you keep all of your emergency supplies.
  • Protect yourself from falling ash.

After an Eruption

  • Avoid driving in heavy ash. Driving will stir up the ash and clog your engine.
  • Stay indoors until authorities say it is safe to come out.
  • Do not go on your roof to remove ash.

Impacts of Volcanic Ash


  • Damage can range from cosmetic to structural depending on the amount and characteristics of the ash fall
  • Contamination of the interior of a building can lead to health impacts for occupants
  • Gutters can become clogged by ash
  • Metal roofs may be vulnerable to corrosion


  • Airports and flights will be shut down when ash is present
  • Roads will become slippery from the ash and the ash caused limited visibility
  • Removal of ash is required for services to return to normal


  • Modern power systems are vulnerable to ash impacts
  • Lines can break due to ash loading
  • Controlled outages during clean up


  • Existing respiratory issues can worsen during ash fall
  • Respiratory and eye symptoms will be common during ash fall


  • Livestock can suffer if food and water supply is contaminated
  • Fluorine poisoning is possible