Volcanic Eruptions: An Overview

About

• Volcanic eruptions are natural disasters which occur as a result of magma, ash, gases and molten rock released by the interior of the earth to the face. They are caused by the accumulation of pressure under the crust of the earth and have a weak area where it can be released. Volcanic activities are either impromptu or long lasting and can take a mild lava flow or a very explosive eruption.
• Contrary to the majority of weather-related disasters, volcanic eruptions take place deep in the ground and might have a long-term environmental, social and economic effect. There are lava flows, ash fall, pyroclastic flows and toxic gases all of which cause eruptions that are very destructive to life, infrastructure and ecosystems.
• Across the world, volcanic activity is clustered along the tectonic plate boundaries and more so at the Pacific ring of fire. Indonesia, Japan, Philippines, Iceland, Italy, Chile and the United States are some of the countries that have volcanic eruptions regularly.
• Volcanic risk is also not high but present in India. The only active volcano in India is the Barren Island volcano of Andaman and Nicobar Islands. Inactive volcanic formations are also present in such areas as Narcondam Island and the Deccan Traps. Volcanic hazards may impact on air travel and marine ecosystems and island population despite the limited exposure.
• The growing influence of volcanic disasters is not related to the frequency of volcanic activities but to advancing population density, development of infrastructure around the volcano areas and the underdeveloped states.

Reasons for a Volcanic Eruption

• Sliding of tectonic plates resulting in either subduction, divergence, or collision provides the channels through which magma can be brought to the surface.
• Magma is piled up under the crust of the earth thus causing pressure until it explodes through vents or cracks.
• Hotspots that occur without the involvement of plate boundaries.
• The magma reacts with groundwater, which may cause eruptions that are explosive in nature.
• Earthquakes may also trigger volcanic activity by changing crustal stress.

Impacts of Volcanic Eruptions

• Human casualties as a result of lava flows, pyroclastic flows, inhalation of ash and poisonous gases.
• Massive demolition of villages, roads, bridges and communication systems.
• Ash fall destroys crops, pollutes water bodies and disturb agriculture and farming.
• Respiratory diseases and air pollution by the fine volcanic ash and sulfur dioxide.
• Hampering of air transport and shipping caused by ash clouds.
• Displacement of the population and livelihoods particularly in tourism and farming in the long run.
• Community psychological stress and trauma.
• In other instances, the volcanic ash may make the soil fertile in the long run hence, benefiting long-term agriculture.

Preparedness to Volcanic Eruption

• Monitoring and Early Warning Systems: Constant monitoring of the seismic activities, gaseous emissions and ground movement by the volcanological agencies.
  • • Sending alerts and hazard maps on time to determine high-risk areas.
• Disaster Preparedness Plans: Community evacuation planning of communities residing around active volcanoes.
  • • The determination of safe shelters and evacuation routes.
    • Frequent mock exercises and preparedness activities at the community level.
• Public Awareness and Communication: Educating local populations on volcanic risks, warning procedures and measures of response.
  • • Real-time information dissemination by use of radio, mobile alerts and local authorities.
• Infrastructure and Land-Use Planning: Settlements and vital infrastructure limitation in risky volcanic areas.
  • • Constructing the buildings to resist ash and little seismic movement.
• Health and Response Emergency: Hoarding masks, medicines and clean drinking water.
  • • Education of medical staff on how to deal with burns, breathing problems and injuries.
• Institutional Coordination: Response and Relief Response and relief coordination between geological agencies, disaster management authorities, local governments and international organizations.

Way Forward

• Volcanic eruptions, which are not common, have a great impact and need scientific attention and a powerful government.
• The mitigation of risks is anchored on incorporation of volcanic hazards assessment in the land-use planning and development policies.
• Early warning systems, which are exposed and prepared to raise awareness and evacuation among communities can save many lives.
• The international collaboration, the exchange of data and studies play an important role in enhancing the eruption prediction and response.
• To reduce losses caused by future volcanic activities, a proactive disaster management system that should be developed should centre on preparedness, resilience and recovery.

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