Q. Mention the global occurrence of volcanic eruptions in 2021 and their impact on regional environment.

Model Answer: 

The year 2021 witnessed elevated volcanic activity globally, primarily concentrated along the Pacific Ring of Fire and divergent plate boundaries, triggering severe regional environmental disruptions.

1. Major Global Volcanic Eruptions in 2021

• Mt. Semeru (Indonesia): Subduction-driven eruption in the Ring of Fire emitting deadly pyroclastic flows.
• Cumbre Vieja (Spain): Oceanic hotspot fissure eruption characterized by prolonged, massive lava flows.
• Mt. Nyiragongo (DRC): Fast-flowing effusive eruption within the East African Rift Valley.
• Fagradalsfjall (Iceland): Gentle fissure eruption located along the Mid-Atlantic Ridge.
• Mt. Aso (Japan): Explosive stratovolcano eruption ejecting massive ash clouds.

2. Impact on Regional Environment

• Atmospheric Degradation: Massive SO2 plumes and ash increased Aerosol Optical Depth, diminishing sunlight and triggering localized acid rain (e.g., La Palma).
• Lithospheric Alteration: Lava flows completely sterilized topsoil and altered topography, although depositing mineral-rich ash for long-term fertility (e.g., Mt. Semeru).
• Hydrospheric Contamination: Toxic ash fallout polluted freshwater reservoirs, drastically increasing water turbidity, heavy metal concentration, and acidity (e.g., Lake Kivu).
• Biospheric Destruction: High-temperature pyroclastic flows instantly incinerated native vegetation, destroying habitats and asphyxiating localized wildlife.

Continuous real-time monitoring via satellite topography and the Volcanic Explosivity Index (VEI) remains critical to predicting eruptions, evacuating communities, and mitigating severe regional environmental catastrophes.