Lateral Blast- explosions of gas and ash from the sides. Ejected materials can travel at the speed of sound. Occurs when magma reacts with water. SO2 and H2S can dissolve in water vapor to produce acid rain. Melting ice or heavy rain generally are the source of H2O. River valleys on the slopes are vulnerable.
Lahars entering lakes or reservoirs can cause large waves.
Some Examples of Devastating Volcanic Events 1. Pyroclastic flows finished off the 4,000 survivorsgathered at the beach. Later buried by lahars. Massive pyroclastic flows. Generated 35 m tsunami that killed 36,000 people.