Forwarded from UPSC Mapping Prelims Mains UPPSC mppsc bpsc
🔆 Melting Glaciers May Trigger Volcanic Eruptions: Study
📍 West Antarctica, Iceland & New Zealand at highest risk
✅ Key Findings
• Melting glaciers & ice caps due to global warming reduce pressure on magma chambers.
• This pressure drop allows magma and gases to expand, triggering explosive volcanic eruptions.
• West Antarctica has ~100 buried volcanoes under ice and is most at risk.
✅ Global Evidence & Trends
• Past deglaciation in Iceland saw 30–50× higher eruption rates.
• Volcanoes beneath ice sheets (e.g., Mocho-Choshuenco, Chile) erupted when pressure dropped post-melt.
• Lower pressure = lower melting point of magma → more eruptions.
✅ Role of Precipitation
• Precipitation, altered by climate change, can penetrate underground, reacting with magma and triggering eruptions.
✅ Climate Feedback Effects
• Volcanic eruptions eject ash & sulfur dioxide into the stratosphere:
– Ash causes temporary cooling by blocking sunlight
– Sulfur dioxide forms reflective aerosols, cooling Earth
• But sustained eruptions release CO₂ and methane, contributing to long-term global warming.
✅ Conclusion
• A vicious cycle is emerging:
– Global warming melts glaciers
– Ice loss triggers eruptions
– Eruptions release GHGs → further warming
#GS1 #Geography #GS3 #ClimateChange #Volcanoes #environment
📍 West Antarctica, Iceland & New Zealand at highest risk
✅ Key Findings
• Melting glaciers & ice caps due to global warming reduce pressure on magma chambers.
• This pressure drop allows magma and gases to expand, triggering explosive volcanic eruptions.
• West Antarctica has ~100 buried volcanoes under ice and is most at risk.
✅ Global Evidence & Trends
• Past deglaciation in Iceland saw 30–50× higher eruption rates.
• Volcanoes beneath ice sheets (e.g., Mocho-Choshuenco, Chile) erupted when pressure dropped post-melt.
• Lower pressure = lower melting point of magma → more eruptions.
✅ Role of Precipitation
• Precipitation, altered by climate change, can penetrate underground, reacting with magma and triggering eruptions.
✅ Climate Feedback Effects
• Volcanic eruptions eject ash & sulfur dioxide into the stratosphere:
– Ash causes temporary cooling by blocking sunlight
– Sulfur dioxide forms reflective aerosols, cooling Earth
• But sustained eruptions release CO₂ and methane, contributing to long-term global warming.
✅ Conclusion
• A vicious cycle is emerging:
– Global warming melts glaciers
– Ice loss triggers eruptions
– Eruptions release GHGs → further warming
📝 Prelims MCQ:
Which of the following effects is caused by volcanic eruptions?
A) Only global cooling
B) Only global warming
C) Both cooling and warming depending on duration
D) Neither cooling nor warming
Answer: C
📝 Mains GS1/GS3 Question:
How does climate change affect volcanic activity and how might this contribute to climate feedback loops?
#GS1 #Geography #GS3 #ClimateChange #Volcanoes #environment
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🔆 Mount Lewotobi Laki-laki – Indonesia
📍 Location & Geology
✅ Situated on Flores Island, East Nusa Tenggara, Indonesia.
✅ Lies along the Pacific Ring of Fire, a tectonically active zone prone to volcanic & seismic activity.
📍 Volcanic System
✅ Part of a twin stratovolcano system with:
• Lewotobi Laki-laki – More frequently active.
• Lewotobi Perempuan – Only two known eruptions in recorded history.
✅ Numerous eruptions from Lewotobi Laki-laki in the 19th & 20th centuries.
📍 Geological Features
✅ Small lava domes formed in summit craters of both peaks (20th century).
✅ Iliwokar flank cone located on the eastern side of Lewotobi Perempuan.
📍 Significance for UPSC
✅ Ring of Fire volcanism – high tectonic hazard zone.
✅ Example of stratovolcano formation & twin volcanic systems.
#UPSC #Geography #Volcanoes #PacificRingOfFire
📍 Location & Geology
✅ Situated on Flores Island, East Nusa Tenggara, Indonesia.
✅ Lies along the Pacific Ring of Fire, a tectonically active zone prone to volcanic & seismic activity.
📍 Volcanic System
✅ Part of a twin stratovolcano system with:
• Lewotobi Laki-laki – More frequently active.
• Lewotobi Perempuan – Only two known eruptions in recorded history.
✅ Numerous eruptions from Lewotobi Laki-laki in the 19th & 20th centuries.
📍 Geological Features
✅ Small lava domes formed in summit craters of both peaks (20th century).
✅ Iliwokar flank cone located on the eastern side of Lewotobi Perempuan.
📍 Significance for UPSC
✅ Ring of Fire volcanism – high tectonic hazard zone.
✅ Example of stratovolcano formation & twin volcanic systems.
📍 UPSC Prelims Practice
Q: Mount Lewotobi is located in which tectonic region?
A) Alpine-Himalayan Belt
B) Pacific Ring of Fire
C) East African Rift
D) Mid-Atlantic Ridge
Correct Answer: ✅ B
#UPSC #Geography #Volcanoes #PacificRingOfFire
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