Remembering Krakatoa © Martin Rietze/Alamy
Over two days in late August 1883, Krakatoa—an uninhabited island near Indonesia—experienced one of the most destructive volcanic eruptions of modern times. Ten times more powerful than the eruption of Mount St. Helens, it obliterated all but a third of the island and triggered massive tsunamis. The biggest blast could be heard 3,000 miles away—it’s still the loudest sound ever recorded. More than 36,000 people lost their lives, and the explosions impacted the entire world for years: Global temperatures dropped and skies darkened, causing huge crop failures. Sunsets turned a vivid red and the moon often appeared blue or green after the event due to the volcanic debris circling in the atmosphere.