Context:
A recent study has found that the eastern Himalayas in Arunachal Pradesh experienced a loss of 110 glaciers between 1988 and 2020.
Key Findings of Glacier Study in Arunachal Pradesh
- Study by:
- Researchers from Nagaland University and Cotton University
- Used remote sensing and GIS technology to track glacier boundaries
- Reduction in Glaciers:
- Number of glaciers decreased from 756 to 646
- Total glacial cover reduced from 585.23 sq. km to 309.85 sq. km (47% loss)
- Glacier Characteristics:
- Most glaciers are located at an elevation of 4,500–4,800 metres
- Predominantly north-facing
- Situated on slopes of 15°–35°
- Consequences:
- Rapid glacial loss has exposed bedrock
- Created glacial lakes
- Raised the risk of glacial lake outburst floods (GLOFs)
Glacial Retreat
- Definition:
- Glacial retreat: glaciers shrinking as ice melts faster than new snow accumulates
- Indicator of global climate change
- Rapidly occurring, especially in high-altitude regions like the Himalayas
- Causes of Glacial Retreat:
- Climate Change:
- Rising global temperatures increase ice melting
- Ice melting surpasses snow accumulation
- Changes in Precipitation Patterns:
- Erratic snowfall patterns
- Reduced winter precipitation slows glacial growth
- Black Carbon Deposition:
- Pollutants from human activities settle on glaciers
- Absorb more heat and accelerate melting
- Geological Factors:
- Slope, altitude, and rock type influence glacier response to warming
- Climate Change:
Glaciers
- Definition:
- Large, slow-moving masses of iceForm in regions where snowfall exceeds melting over long periods
- Act as natural freshwater reservoirs
- Play a crucial role in regulating the Earth’s climate and water cycle
- Formation of Glaciers:
- Accumulation: Snowfall collects in high-altitude or polar regions
- Compaction: Layers of snow compress under their own weight over time, forming dense ice
- Glacial Movement: Glaciers move downslope due to gravity & carve the landscape as they advance
- Ablation: Ice melts due to temperature changes
Major Glaciers in India
- Siachen Glacier (Ladakh): Longest glacier in India (76 km)
- Gangotri Glacier (Uttarakhand)
- Yamunotri Glacier (Uttarakhand)
- Zemu Glacier (Sikkim): Largest glacier in the Eastern Himalayas
- Rathong Glacier (Sikkim): Supplies water to the Teesta River
- Milam Glacier (Uttarakhand): Major source of the Goriganga River
- Pindari Glacier (Uttarakhand)
Source: TH
Previous Year Question
Consider the following pairs
Glacier: River
1. Bandarpunch : Yamuna
2. Bara Shigri: Chenab
3. Milam: Mandakini
4. Siachen: Nubra
5. Zemu: Manas
Which of the pairs correctly matched?
[UPSC CSE – 2019 Prelims]
(a) 1, 2 and 4
(b) 1, 3 and 4
(c) 2 and 5
(d) 3 and 5
Answer: (a)
Explanation:
Milam Glacier (Kumaon Himalaya) is the source of the Goriganga River.
Mandakini River, a tributary of the Alaknanda River, originates from the Chorabari Glacier near Kedarnath in Uttarakhand, India.
Zemu Glacier (largest in the Eastern Himalaya) feeds numerous rivers, including the Teesta River.
Manas River is a transboundary river in the Himalayan foothills between southern Bhutan and India.