UPSC MainsGENERAL-STUDIES-PAPER-I202110 Marks150 Words
Q7.

Mention the global occurrence of volcanic eruptions in 2021 and their impact on regional environment. (Answer in 150 words)

How to Approach

The question requires a factual account of volcanic eruptions in 2021 and their environmental consequences. A structured approach is crucial. Begin by listing major eruptions, then detail their regional impacts – atmospheric, geological, and biological. Focus on specific locations and observed effects. The answer should demonstrate awareness of volcanic processes and their environmental linkages. Prioritize recent data (2021) and avoid generalizations. A concise, geographically organized response is ideal.

Model Answer

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Introduction

Volcanic eruptions are powerful geological events that significantly alter regional and global environments. 2021 witnessed several notable eruptions, each with unique characteristics and impacts. These events release gases, ash, and lava, affecting air quality, water resources, and ecosystems. Understanding these impacts is crucial for disaster preparedness and environmental management. The year 2021 saw increased volcanic activity compared to previous years, largely driven by plate tectonic movements and magma chamber dynamics. This answer will detail the major eruptions of 2021 and their corresponding regional environmental consequences.

Major Volcanic Eruptions of 2021

Several volcanoes exhibited significant eruptive activity in 2021. Key events included:

  • Semeru, Indonesia (December 2021): This was the most devastating eruption of the year, triggering pyroclastic flows and lahars, causing widespread destruction and loss of life.
  • Cumbre Vieja, La Palma, Canary Islands (September-December 2021): An 85-day eruption caused significant lava flows, ashfall, and gas emissions, impacting agriculture and infrastructure.
  • Kilauea, Hawaii (Ongoing, with increased activity in 2021): Eruptions within Halemaʻumaʻu crater continued, releasing volcanic gases and creating a lava lake.
  • Sakurajima, Japan (Frequent small to moderate eruptions throughout 2021): Ashfall disrupted daily life and posed health risks to nearby populations.
  • Mount Nyiragongo, Democratic Republic of Congo (May 2021): A flank eruption caused lava flows that threatened Goma city, leading to mass displacement.

Regional Environmental Impacts

1. Atmospheric Impacts

Volcanic eruptions release substantial amounts of gases, including sulfur dioxide (SO2), carbon dioxide (CO2), and water vapor. SO2 can react with water vapor to form sulfuric acid aerosols, which reflect sunlight and can cause temporary global cooling. Ash particles also contribute to atmospheric opacity.

  • La Palma: Ashfall blanketed large areas, impacting air quality and disrupting air travel. Sulfur dioxide emissions led to acid rain, damaging vegetation.
  • Semeru: Ash clouds caused respiratory problems and reduced visibility, impacting transportation and agriculture.

2. Geological Impacts

Eruptions alter landscapes through lava flows, pyroclastic flows, and ash deposition. Lahars (mudflows) can cause significant erosion and sedimentation.

  • La Palma: Lava flows destroyed homes, infrastructure, and agricultural land, significantly altering the island’s topography.
  • Mount Nyiragongo: Lava flows destroyed villages and infrastructure, displacing thousands of people.
  • Semeru: Pyroclastic flows and lahars buried villages and agricultural land, causing widespread devastation.

3. Biological Impacts

Volcanic eruptions can have both short-term and long-term impacts on ecosystems. Ashfall can damage vegetation, while volcanic gases can acidify soils and water bodies. However, volcanic ash also contains nutrients that can enrich soils over time.

  • La Palma: Vegetation was destroyed by lava flows and ashfall. The long-term impact on the island’s unique ecosystems is still being assessed.
  • Kilauea: Volcanic gases impacted native plant and animal life in the surrounding areas.
Volcano Primary Impact Regional Area Affected
Semeru Pyroclastic Flows & Lahars East Java, Indonesia
Cumbre Vieja Lava Flows & Ashfall La Palma, Canary Islands
Nyiragongo Lava Flows Goma, Democratic Republic of Congo

Conclusion

The volcanic eruptions of 2021 demonstrated the significant environmental hazards posed by these geological events. From atmospheric disruption and landscape alteration to ecological damage and human displacement, the impacts were far-reaching. Continued monitoring of volcanic activity, improved early warning systems, and effective disaster preparedness strategies are crucial for mitigating the risks associated with future eruptions. Furthermore, understanding the long-term ecological recovery processes in affected regions is essential for sustainable environmental management.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Pyroclastic Flow
A fast-moving current of hot gas and volcanic matter (ash, pumice, rock) that flows along the ground away from a volcano.
Lahar
A destructive mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. Lahars can travel long distances and pose a significant threat to communities downstream from volcanoes.

Key Statistics

The eruption of Mount Nyiragongo in May 2021 displaced over 400,000 people.

Source: UNOCHA (United Nations Office for the Coordination of Humanitarian Affairs) - as of knowledge cutoff 2023

Global Volcanic Activity reports that approximately 50-70 volcanoes are erupting at any given time.

Source: Smithsonian Institution's Global Volcanism Program - as of knowledge cutoff 2023

Examples

Mount Pinatubo, 1991

The 1991 eruption of Mount Pinatubo in the Philippines released approximately 20 million tons of sulfur dioxide, causing a global temperature decrease of about 0.5°C for several years.

Frequently Asked Questions

What is the Volcanic Explosivity Index (VEI)?

The VEI is a scale from 0 to 8 that measures the explosiveness of volcanic eruptions. It considers factors like the volume of ejected material, eruption column height, and duration of the eruption.

Topics Covered

GeographyEnvironmentVolcanismNatural DisastersClimate