An earthquake of magnitude 8.8 struck Russia's Kamchatka Peninsula triggering tsunami waves near Kuril Islands in the Pacific Ocean.
About Tsunami
- It is a series of extremely long waves caused by a large and sudden displacement of the ocean, usually the result of an earthquake below or near ocean floor e.g. Indian Ocean Tsunami (2004).
- Causes: Earthquakes, landslides, volcanic eruptions, glacier calvings, meteorites, other underwater explosions (including nuclear).
- Tsunamis are frequently observed along the Pacific Ring of fire.
- Ring of Fire is a belt of active and dormant volcanoes surrounding the Pacific Ocean.
Characteristics of Tsunami Waves:
- Wavelength: Their speed & wavelength primarily depends on ocean depth, not distance from the wave's source.
- Wavelength in the deep ocean is approx. 200 km and near coast, it reduces to less than 20 km due to shoaling.
- Wave Height (Amplitude): Not noticed by ships in deep oceans because their amplitude is negligible.
- However when tsunamis approach shallow water, wave amplitude increases.
Consequences:
- Socio-Economic: Destruction of property, Loss of lives and livelihoods.
- Environmental: Destroying Mangroves, coral reefs, estuaries, also leads to Soil and Water Contamination.
- Others: Disruption of essential services, psychological stress etc.
NDMA Guidelines for Tsunami
|
