Volcano

Volcano

A volcano is an opening in the Earth’s crust that allows molten rock, gases and debris to escape to the surface. During a volcanic eruption, lava and other debris can flow at speeds of up to 100 mph, destroying everything in their path. Volcanic ash can travel hundreds of miles and cause severe health problems.

Eruption Hazards

Lava Flows

    • Rivers of molten rock are extremely hot
      • Lava flows can exceed a searing 2,000 degrees Fahrenheit
      • Some can be readily out-walked, others rush surprisingly quickly

Volcanic Projectiles

    • Blistering-hot avalanches of gasses, rocks, and volcanic ash
      • Barrel down a volcano’s slopes, burying structures, sparking fires, and destroying everything in their path
      • Extremely speedy, with some rushing as fast as 450 miles per hour

Lahars or debris flows

    • Hot or cold slurry of water and rock fragments that rushes down a volcano’s slopes
    • Follow valleys or river channels and can move startlingly fast

Toxic gases

    • Carbon dioxide, carbon monoxide, sulfur dioxide, and hydrogen chloride
    • Extremely corrosive and can irritate the skin, eyes, and respiratory systems
    • In rare cases, the gasses can be deadly

Volcanic ash

    • Made up of tiny fragments of rock and shards of glass
    • Damaging to lungs and can form a hefty blanket over nearby towns
    • Can also shoot miles high into the sky and rain down for many miles around

Preparing for an Eruption

Unlike earthquakes, volcanoes rouse from sleep with some notice—shaking the ground, bulging their flanks, or shifting the gases wafting from their craters and vents. And for many volcanoes near populations, scientists closely watch their every move, which allows them to better understand when they might burst to life.

So if you live near a volcano, or plan to visit one, familiarize yourself with the local monitoring agencies. Understand where you can safely tromp and where you need to steer clear, regions known as exclusion zones. It’s also important to look up evacuation routes and hazards specific to your location.

Some places offer regular updates of volcanic activity. For example, the U.S. Geological Survey’s Volcano Notification Service emails information about monitored volcanoes in the United States, which boasts more than 10 percent of the planet’s active or potentially active volcanoes.

Another vital preparation step is assembling an emergency kit that includes supplies like food, water, respiratory protection, eye protection, and a battery-powered radio. When preparing your kit, consider each member of your family and their needs—and don’t forget your pets. The Department of Homeland Security has a detailed guide about putting together a kit for many different contingencies.

Even if you are just visiting a volcano for a day, make sure you are traveling with appropriate footwear, first aid supplies, and plenty of water.

IF YOU ARE UNDER A WARNING

    • Listen for emergency information and alerts.
    • Follow evacuation or shelter orders. If advised to evacuate, do so early.
    • Reduce your ash exposure by doing the following:
      • Limit your time outdoors and use a dust mask or cloth mask as a last resort if you must be outside.
      • Avoid areas downwind and river valleys downstream of the volcano.
      • Take temporary shelter from volcanic ash in the location where you are.
      • Cover ventilation openings and seal doors and windows.
      • Avoid driving in heavy ash. If you must drive, keep the windows up and do not use the air conditioning system.
      • Do not get on your roof to remove ash.
      • Stay indoors until authorities say it is safe to go outside.

Volcanic Information

For more information

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