The sudden violence of volcanic eruptions causes catastrophe and devastation.  Various notorious eruptions of volcanoes in the past, such as Mount Pelée, Tambora, Krakatau and Pinatubo have demonstrated the devastating impact of volcanic activity on nearby landscapes and communities.  Many people got killed.  A big number of people had to abandon their homes and land forever.  Even the whole world's climate was changed for a while as a result of an eruption!

These effects of volcanic eruptions are mostly the result of certain hazards.  Volcanoes provide different hazards during an eruption.  Each hazard poses different risks affecting different areas.  The most threatening hazards include:

• Pyroclastic Flows
• Nuées Ardentes
• Volcanic Ashes
• Lahars
• Debris Avalanches, Landslides, Tsunamis
• Blast
• Lava
• Types of Lava Flows
• Gas