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.
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.