Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclones etc.,
Q1. How can India adopt earthquake readiness from the seismic zone countries around the world, especially in building safer structures and enforcing seismic codes, given its infrastructure expansion in seismic regions like the Himalayas with recent examples?
Earthquakes are confined to specific geographic zones, a phenomenon elucidated by plate tectonics. The Earth’s lithosphere, comprising 15 large plates, undergoes perpetual movement, leading to concentrated seismic activity, notably at convergent plate boundaries such as the Himalayas, formed by the convergence of the Indian and Eurasian plates.
In the past two decades, significant earthquakes hit various regions worldwide, revealing tectonic similarities, as evidenced by Taiwan’s recent quake of 7.4 magnitude.
Seismic zones of the world:
● The most important earthquake belt is the Circum-Pacific Belt, which affects many populated coastal regions around the Pacific Ocean—for example, those of New Zealand, New Guinea, Japan, Taiwan, the Aleutian Islands, Alaska, and the western coasts of North and South America. The Pacific Ring of Fire accounts for about 68 per cent of all earthquakes.
● Alpine Belt (Himalayas and Alps): The Mid Continental Belt (Alpine Belt) extends parallel to the equator from Mexico across the Atlantic Ocean, the Mediterranean Sea from Alpine-Caucasus ranges to the Caspian, Himalayan mountains and the adjoining lands.
● Mid-Atlantic Ridge: including those in the Arctic Ocean, the Atlantic Ocean, and the western Indian Ocean—and along the rift valleys of East Africa.
Earthquake zone in India:
● Over 59 % of India’s land area is under threat of moderate to severe earthquakes.
● The Bureau of Indian Standards, based on the past seismic history, divided the country into four seismic zones, viz. Zone II, III, IV and V.
● Zone V is the most seismically active region which is the Himalayas.
Earthquake in Himalayas:
● Nepal Earthquake Aftershocks (2015): Following the devastating earthquake in Nepal on April 25, 2015, numerous aftershocks were felt in India, particularly in regions bordering Nepal, including Bihar, Uttar Pradesh, and West Bengal.
● On April 4, 2024, Manali in Himachal Pradesh experienced a magnitude 5.3 earthquake.
Infrastructure problems in Himalayas:
● India’s infrastructure expansion in tectonically unstable regions, like the Himalayas, often disregards ecological norms.
● Construction codes: There is a lack of adherence to mountain construction codes and basic safety protocols.
● Carrying capacity: The broader issue of carrying capacity needs to be addressed, including hydropower projects, tourism, and road development.
● Joshimath: In January 2023, cracks suddenly spread over hundreds of buildings in Joshimath, India, and they started sinking into the ground.
Taiwan earthquake:
● In the Taiwan region, the Philippine Sea plate moves north-westward towards the Eurasian plate at approximately 7.8 cm per year.
● Despite similar magnitudes, the 2024 Hualien earthquake caused minimal damage compared to the 1999 quake.
● Taiwan’s stringent building codes and administrative reforms post-1999 significantly reduced casualties and infrastructure damage.
The Taiwan earthquake offers crucial lessons to India:
● Taiwan boasts advanced earthquake preparedness globally.
● It has the most sophisticated earthquake-monitoring network and early warning systems.
● Public awareness campaigns and drills have enhanced understanding of earthquake risks.
● The government regularly updates earthquake safety requirements for buildings.
● Incentives are provided for residents to improve building quake resistance.
● Scientific assessments determine shaking severity in each location.
● Specific seismic codes and construction norms are devised accordingly.
● Taiwan utilises modern technologies like seismic dampers and base isolation systems.
Way forward: India must prioritise earthquake safety amid infrastructural growth, especially in seismic regions like the Himalayas. Key lessons from Taiwan include strict adherence to seismic codes, constructing resilient structures, and addressing enforcement gaps. Tailored seismic designs and promoting earthquake-resistant traditional architecture are crucial steps forward.
Source The Hindu
https://epaper.thehindu.com/ccidist-ws/th/th_chennai/issues/80355/OPS/GD4CN5535.1+G7PCN5FJT.1.html