20 Years of Indian Ocean Tsunami 2004 | 26 Dec 2024

Source: TH 

Why in News?  

• 26^th December 2024, marked the 20^th anniversary of the 2004 Indian Ocean earthquake and tsunami. 

What was the 2004 Indian Ocean Earthquake and Tsunami? 

• Origin and Cause: The earthquake had a magnitude of 9.1, making it the third-largest earthquake [Others two: Chile, 1960 (magnitude 9.5) and Alaska, 1964 (magnitude 9.2)] recorded globally since 1900. 
  • The earthquake originated in the Sunda Trench, where the Indo-Australian plate subducts beneath the Burma microplate (part of the Eurasian plate). 
• Geographic Impact: It affected an astounding 1,300 km from Sumatra in the south to the Coco Islands in the north.  
  • The earthquake’s tremors were felt across Indonesia, Bangladesh, India, Malaysia, Maldives, Myanmar, Singapore, Sri Lanka, and Thailand. 
  • In Car Nicobar, the Indian air force base was completely destroyed, underscoring the scale of destruction. 
• Death and Displacement: The tsunami resulted in an estimated over 227,000 deaths, making it the deadliest tsunami in recorded history. 
  • Over 1.7 million people were displaced due to the destruction of homes and infrastructure. 
• Lessons for India: India didn't anticipate such a large event along India's eastern coast, as the only previous tsunamis occurred in 1881 (from a large earthquake near Car Nicobar island) and 1883 (from the Krakatoa explosion), both producing only small surges. 
• Reduction in Mortality: The 1999 Odisha super cyclone killed over 10,000 people while Cyclone Yaas (2021) resulted in fewer than six casualties that shows India has made significant progress in disaster risk reduction (DRR). 
  • However, infrastructure damage caused due to cyclones is still a cause of concern. E.g., Cyclone Dana (2024) caused widespread damage in Odisha that is estimated at Rs 616 crore. 

What Initiatives Were Taken after the 2004 Indian Ocean Tsunami to Minimise Damages? 

• Early Warning Systems: The Indian Tsunami Early Warning Centre (ITEWC) was established in 2007 by the Union Ministry of Earth Sciences. 
  • ITEWC operates from the Indian National Centre for Ocean Information Services (INCOIS) in Hyderabad, using seismological stations, bottom pressure recorders, and tidal stations across the Indian Ocean basin to detect and issue early warnings for potential tsunamis. 
    • The ITEWC functions as an approved Tsunami Service Provider of the Indian Ocean Tsunami Warning & Mitigation System (IOTWMS) that is an integral part of the Global Tsunami Warning and Mitigation System. 
  • Global, there are around 150 stations worldwide monitoring seismic activity, and Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys track changes in pressure on the seafloor to detect tsunami generation. 

• Real-time Monitoring: Real-time ocean monitoring systems were developed to detect tsunami-producing earthquakes and issue alerts in as little as 10 minutes. 
  • India became the 5^th country globally to have an advanced tsunami warning system, joining the US, Japan, Chile, and Australia. 
  • Globally, sea-level monitoring stations have increased from just one in 2004 to 14,000 today, to detect rising sea levels and potential tsunamis. 
• Technological Advancements: The early warning systems now use better algorithms and faster supercomputers enabling rapid modeling, allowing for faster and more accurate predictions of tsunami behavior. 
• Tsunami Geology Research: The work of tsunami geology, pioneered by Brian Atwater of the US Geological Survey started to search for evidence of tsunamis in history.   
  • Investigations of mangrove swamps and coastal areas led to the discovery of past tsunami events (1,000 years ago) in the Andaman and Nicobar Islands and Mahabalipuram (a port of the Pallava dynasty). 
• Research on Slow Slips: Researchers started studying seismic slips at plate boundaries to understand the processes that occur before and after major earthquakes. 
  • Investigations indicated a perceptible downward ground movement in South Andaman between 2003 and 2004, before the megathrust earthquake of 2004. 
• Nuclear Plant Vulnerability Studies: Following the 2004 tsunami, researchers assessed the vulnerability of nuclear power plants, such as Kalpakkam, to tsunami risks. 
  • The Kalpakkam nuclear plant shut down automatically due to rising water levels and the reactor restarted after six days. 
• Inundation Studies: Tsunami modelling using mathematical tools helped identify inundation limits and assess risks to coastal infrastructure. 
• Focus on High-Risk Areas: Experts began to study other high-risk areas like the Makran Coast (Iran and Pakistan) and the Myanmar coast. 
  • The Makran Coast could direct a tsunami towards India's west coast,  impacting Mumbai and nuclear reactors. 
• Global Cooperation: The tsunami warning system has become more globally coordinated, with countries working together to monitor earthquakes and tsunamis. 
  • E.g., After the 2004 Indian Ocean tsunami, UNESCO Intergovernmental Oceanographic Commission (IOC) was tasked with establishing global tsunami warning services across ocean basins.   

Conclusion 

The 2004 Indian Ocean tsunami highlighted critical gaps in early warning systems, prompting significant advancements in global and regional tsunami preparedness. Initiatives such as the establishment of ITEWC, enhanced monitoring, and international cooperation have drastically improved disaster response, yet challenges remain, particularly in developing nations.