Explosive volcanoes are characterized by violent eruptions that can send ash, gas, and lava high into the atmosphere. These eruptions occur when magma rises to the surface and traps gases, creating pressure. When the pressure becomes too great, it results in a powerful explosion, often producing pyroclastic flows and volcanic ash that can affect areas far from the volcano. Famous examples of explosive volcanoes include Mount St. Helens in the United States and Mount Vesuvius in Italy. These volcanoes are typically found at convergent plate boundaries, where tectonic plates collide, leading to the formation of magma that fuels explosive activity.