ENVIRONMENT Turrialba in Costa Rica has rumbled to life in what may be its strongest eruption in years, diverting flights and choking San José with ash and fumes. (Nat Geo News) What is volcanic ash? Why is it such a hazard? Check out our great encyclopedic entry to find out. Teachers, scroll down for a quick list of key resources in our Teachers Toolkit, including … Continue reading Costa Rican Volcano Spews Ash Sky-High