Tsunami and Volcanic Eruption Hazards: Causes, Impacts, and Prevention

Tsunami Causes and Impacts

Earthquakes are the primary cause of tsunamis. To a lesser extent, volcanic eruptions can also trigger these devastating waves. Tsunamis are generated when a seabed earthquake causes an abrupt vertical movement of the ocean floor, displacing a massive volume of water. The size of the tsunami waves is directly related to the magnitude of the earthquake or volcanic eruption.

Major Tsunami Risk Areas

1. Indonesia
2. Santorini (Greece)
3. Japan

Five Worst Tsunamis in History

1. Indonesia, 2004: 230,000 fatalities, extensive infrastructure damage, and a shift in the Earth's rotational axis.
2. Sri Lanka, 2004: Significant casualties and economic losses due to the same tsunami as Indonesia.
3. India, 2004: 9,000 dead, 100 missing, and long-term displacement of thousands.
4. Thailand, 2004: Widespread destruction of crops, coastline, and infrastructure, resulting in substantial financial and psychological impacts.
5. Somalia, 2004: The earthquake and subsequent tsunami caused numerous deaths and disappearances, exacerbating existing humanitarian challenges. The magnitude 9.0 earthquake released energy equivalent to 475 megatons (23,000 Hiroshima bombs), affecting a third of the planet and altering Earth's rotation.

Volcanic Eruption Prevention and Mitigation

Volcanic Eruption Prevention

Volcanic eruption prevention encompasses measures taken to reduce volcanic risk before, during, and after an eruption. Effective prevention requires understanding volcanic processes and hazards specific to each area.

The Canary Islands, Spain, are a significant volcanic region. The Teide volcano (Tenerife) was selected by the UN as a Decade Volcano for the International Decade for Natural Disaster Mitigation (1990-2000), highlighting its high-risk status. The archipelago's volcanic history spans over 20 million years, with the most recent eruption being the Teneguía volcano (La Palma) in 1971.

Preventive Measures for Volcanic Areas

• Ongoing volcanic activity monitoring
• Effective warning systems
• Appropriate land use and management
• Comprehensive emergency planning
• Public education and outreach

Volcanic Eruption Mitigation

Correction methods are implemented after an eruption. In evacuated areas, the focus shifts to repairing damaged infrastructure and providing aid to displaced populations. Milder mitigation measures include diverting lava flows through canals to minimize damage.