NISAR satellite to map Himalayas’ seismic zones

Subject : Science and technology

Section: Space technology

Concept :

NISAR satellite is going to map the most earthquake-prone regions in the Himalayas with unprecedented regularity and aims to build an advance warning system of land subsidence and earthquakes.

Need of the initiative:

A large section of the Himalayan region falls in Zone V, implying the highest risk of strong earthquakes.
The NISAR satellite will use two frequency bands: the L-band and S-band to image the Himalayan region.
These two frequency bands will together provide high-resolution, all-weather data from the satellite that is expected to follow a sun-synchronous orbit.
Frequency to map:
The seismically active Himalayan region that will, every 12 days, create a “deformation map”.
The map is going Map the Strain which refers to the deformation that occurs in rocks when it is under pressure from other rocks, usually due to movements of continental plates that are sliding, colliding, or subducting against each other.
Note : The Indian Plate collided into the Eurasian plate forming the Himalayas and continues to incrementally push it upwards.
Scientists from the Geological Survey of India in 2021 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.

Significance:

It will also serve as a valuable tool to give warning of land subsidence as scientists can use the data collected and under all-weather conditions to study deformation patterns.
The geoscience community can use this to determine how strain is building up in various parts of the Himalayas.

About NISAR:

NISAR stands for NASA-ISRO Synthetic Aperture Radar.
NISAR satellite was jointly developed by the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) of the U.S.
NISAR is expected to be launched in January 2024 from Satish Dhawan Space Centre into a near-polar orbit.
It is an Earth observation satellite.
The 2,800 kilograms satellite consists of both L-band and S-band synthetic aperture radar (SAR) instruments, which makes it a dual-frequency imaging radar satellite.
NASA has provided the L-band radar, GPS, a high-capacity solid-state recorder to store data, and a payload data subsystem.
And the ISRO has provided the S-band radar, the GSLV launch system and spacecraft.
Another important component of the satellite is its large 39-foot stationary antenna reflector
It is made of a gold-plated wire mesh, the reflector will be used to focus the radar signals emitted and received by the upward-facing feed on the instrument structure.