From UPSC perspective, the following things are important :
Prelims level: NISAR, Seismic Zones
Mains level: Read the attached story
Central idea
- The ISRO and the NASA have jointly developed a forthcoming satellite called NISAR.
- It will map the most earthquake-prone regions in the Himalaya.
What is NISAR?
- NISAR stands for NASA-ISRO Synthetic Aperture Radar.
- The mission aims to provide global measurements of the causes and consequences of land surface changes using advanced radar imaging.
- The satellite is equipped with two types of synthetic aperture radars (SAR): L-band and S-band, which will allow for high-resolution, all-weather imaging of the Earth’s surface.
- The NISAR satellite is expected to be launched in January 2024.
How it will be used for earthquake monitoring?
- It will generate data that can potentially give advance warning of land subsidence and identify places that are at greatest risk from earthquakes.
- The geoscience community can use this to determine how strain is building up in various parts of the Himalayas.
- Strain refers to the deformation that occurs in rocks when it is under pressure from other rocks.
- Movements of continental plates that are sliding, colliding, or subducting against each other cause strain.
- With a frequency of 12 days and the ability to provide images even under cloudy conditions, NISAR would be a valuable tool to study deformation patterns, such as in Joshimath.
Strain Map already in place
- In 2021, scientists from the Geological Survey of India published a “strain map” of the Himalayas based on data from 1,252 GPS stations along the Himalayas.
- It identified regions that had the greatest odds of generating earthquakes of magnitude above 8 and their extent.
- However, these many stations are still too few, and there’s only one satellite (Sentinel) that we rely on.
- With NISAR, the costliest space mission ever, we can have a game-changer in earth-science observation.
Seismic Zones of India
India is divided by Bureau of Indian Standards (BIS) into 4 seismic zones based on the level of seismicity and the frequency of earthquakes that occur in that particular region. These zones are as follows: 1. Zone 2: This is a low seismic zone comprising of areas with the lowest risk of earthquakes. It includes regions like the northeastern states of India, parts of J&K, Himachal Pradesh, and Uttarakhand. 2. Zone 3: This is a moderate seismic zone comprising of areas that are at moderate risk of earthquakes. It includes regions like Gujarat, Haryana, Delhi, parts of UP, Bihar, West Bengal, and parts of Jharkhand. 3. Zone 4: This is a high seismic zone comprising of areas that are at high risk of earthquakes. It includes regions like the A&N Islands, parts of Himachal Pradesh, J&K, Uttarakhand, and the entire northeastern region. 4. Zone 5: This is a very high seismic zone comprising of areas that are at the highest risk of earthquakes. It includes regions like the entire state of J&K, Himachal Pradesh, Uttarakhand, the entire northeastern region, parts of Gujarat, Rajasthan, Maharashtra, and the A&N Islands. |
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zones are wrongly matched , please correct them