Pelean eruptions are the most violent because they involve magma with a very high silica content. This makes the magma thick and sticky, preventing gases from escaping easily. Consequently, a lava dome often forms over the vent, acting like a cork in a pressurized bottle. When the dome fails, it triggers a catastrophic lateral blast. The most terrifying feature is the pyroclastic flow—a dense, turbulent cloud of incandescent ash and gas that can reach temperatures of 1,000 degrees Celsius. These flows move at hundreds of miles per hour, making the Pelean type the deadliest volcanic category.