Earthquake in Japan triggered Tsunami

05 Jan Earthquake in Japan triggered Tsunami

This article covers ‘Daily Current Affairs’ and the topic details of ‘massive earthquake in Japan, prompted tsunami concerns.’ This topic is relevant in the “Disaster and Disaster Management” section of the UPSC CSE exam.

UPSC MAINS SYLLABUS GS3 PAPER : Disaster and Disaster Management

Why in the News?

A 7.5 magnitude earthquake rocked central Japan, toppling buildings, igniting fires, and sending tsunami warnings as far away as eastern Russia, prompting orders for citizens to evacuate Japan’s affected coastal areas.

What is a Tsunami ?

• A tsunami is a series of exceptionally long-wavelength ocean waves with high energy, often triggered by a big and rapid disturbance in or near a body of water. Tsunami is a Japanese word used for “harbour wave.”
• Tsunamis, despite their long wavelengths, can travel at great speeds across open sea. The waves compress and grow in height as they approach shallow coastal areas, producing disastrous floods and destruction when they reach the shore.

The main drivers of tsunami formation are –

Tsunamis are primarily triggered by underwater disturbances that cause a massive volume of water to be displaced. The following are the most common causes of tsunamis:

• Underwater Earthquakes: Underwater earthquakes, particularly those of large magnitude, cause the majority of tsunamis. When tectonic plates below the ocean floor rapidly shift, a huge quantity of water is displaced, resulting in enormous tsunami waves.
• Volcanic Eruptions : Underwater volcanic eruptions can result in the development of tsunamis. When magma and gases are ejected from a volcano below the sea, they force the surrounding water to shift, resulting in tsunami waves.
• Submarine Landslides: Landslides on the ocean floor, particularly in coastal or subsea locations, can displace water and cause tsunamis. These landslides can be caused by a variety of events, such as volcanic activity, underwater mining, or even basic instability of underwater slopes.
• Meteorite Impacts: Large meteorites striking the ocean can occasionally displace enough water to cause tsunami waves. The energy generated during impact can cause waves to propagate over the ocean.
• Anthropogenic Factors : Tsunamis can be caused by anthropogenic factors too, such as underwater nuclear explosions.For example, nuclear testing by the United States triggered a tsunami in Marshall Island in the 1940s and 1950s.

India’s Tsunami Preparation

• Indian Tsunami Early Warning System (ITEWS) of India: ITEWS was established to provide early alerts about impending tsunamis. A network of seismological and tide gauge stations, as well as a deep ocean assessment and reporting system (DOARS), are part of this system, which monitors and detects tsunami-generating earthquakes.Indian Tsunami Early Warning System Centre (ITEWC) is located at the Indian National Centre for Ocean Information Services (INCOIS) in Hyderabad.
• Public Education and Awareness : INCOIS conducts mock drills and organises workshops/training on tsunami awareness and preparedness in collaboration with the National Disaster Management Authority (NDMA).
• Evacuation Plans: Tsunami-prone coastal areas have evacuation plans in existence. These plans include defined evacuation routes, assembly places, and the creation of safe zones or shelters where people can seek refuge in the event of a tsunami.
• Part of the Indian Ocean Tsunami Warning System : India is one of the members of the Indian Ocean Tsunami Warning System (IOTWS) The acquired data is used to send timely warnings to coastal populations.
• Community Drills and Training: Residents in coastal towns receive exposure to regular drills and training sessions to ensure that they are familiar with evacuation protocols and know how to respond in the case of a tsunami warning. This could include simulated evacuation drills and community-based training programmes.
• Monitoring software for earthquakes and multimode tsunami early warning systems :
  (a)INCOIS already has the necessary software in place for monitoring earthquakes.
  (b)INCOIS has additionally developed Decision Support System software for automatically producing and disseminating tsunami alerts for effective tsunami early warning information distribution. For example, INCOIS has created interfaces to the NDMA Common Alert Protocol (CAP) system. Additionally, it created the INCOIS smartphone app “SAMUDRA – Smart Access to Marine Users for Ocean Data Resources and Advisories.”

Reasons behind high frequency of Earthquake and Tsunami in Japan

• This is due to its position. Japan is located along the ‘Pacific Ring of Fire,’ the world’s most active seismic tectonic region.
• According to a report by Live Science, the ‘ring’ refers to “an imaginary horseshoe-shaped zone located around the rim of the Pacific Ocean, where the majority of the world’s earthquakes and volcanic eruptions occur.”
• Within the Ring of Fire, many tectonic belts, such as the Pacific Plate, Eurasian Plate, and Indo-Australian Plate, are constantly meshing and clashing, leading to earthquakes, volcanic eruptions, and tsunamis.

Conclusion

Tsunamis caused by seismic or volcanic activity are formidable natural hazards that have the ability to have devastating results along coasts. Governments around the world, including India, have put in place sophisticated contingency plans that include early warning systems, community education, and infrastructure resilience. These measures are pivotal in minimising casualties and damage.

Prelims practice questions

Question 1) What differentiates tsunami waves from normal waves as they approach the coastline?

A) Low energy and short wavelength
B) Low amplitude and slow pace
C) High energy and long wavelength
D) Patterns that are irregular and unexpected

Ans- C

Question 2) Which ocean is most vulnerable to tsunamis due to its seismic activity?
a. the Atlantic Ocean
b. the Indian Ocean
c. Pacific Ocean
d. Arctic Ocean

Ans -D

Mains practice questions

Question 1) Examine the efficacy of India’s early warning systems in minimising the effects of natural catastrophes. Consider factors such as technological developments, community engagement, and response coordination.

Question 2) Analyse the socioeconomic consequences of large-scale displacements in India caused by calamities. Investigate the long-term effects on affected populations, their livelihoods, and the government’s response to these difficulties.

Himanshu Mishra

I am a content developer and have done my Post Graduation in Political Science. I have given 2 UPSC mains, 1 IB ACIO interview and have cleared UGC NET JRF too.