By: Vinod Chandrashekhar Dixit
5th November is observed as the World Tsunami Awareness Day to raise awareness for early warnings and actions to protect people, save lives, and prevent the hazard from becoming a disaster. The word “tsunami” comprises the Japanese words “tsu” (meaning harbour) and “nami” (meaning wave). A tsunami is a series of enormous waves created by an underwater disturbance usually associated with earthquakes occurring below or near the ocean. A tsunami is a kind of natural disaster which is caused due to volcanic eruptions in the ocean beds. Tsunamis are natural occurrences in which a series of powerful waves cause a surge in water that can reach heights of several metres.
Tsunamis occur primarily in areas where two continents meet. Tsunamis also happen due to volcanic eruptions under the ocean beds. The Pacific Ocean is well-known for the frequent occurrence of tsunamis. Tsunamis cause a lot of damage to the environment. It destroys the buildings, forests, livelihood, etc. Since it is a sudden event, no one can anticipate its occurrence. Tsunamis are rare events but can be extremely deadly. In the past 100 years, 58 of them have claimed more than 2,60,000 lives, or an average of 4,600 per disaster, surpassing any other natural hazard. Tsunami waves often look like walls of water and can attack the shoreline and be dangerous for hours, with waves coming every 5 to 60 minutes. Tsunami is defined as a sequence of ocean waves with a very long wavelength. Due to the tsunami, strong waves of water are created and move landwards. As a result, there is a large inland water movement that lasts for a long time.
As a result, these waves have a significant destructive power. Like any other natural disaster, tsunamis bring massive destruction to the environment. The leading cause of a tsunami is attributable to an earthquake. However, even volcanic eruptions, landslides and comets or other heavenly bodies hitting the sea can be a source. Japan is the country which has recorded the most significant number of tsunamis. The tsunami generated in the Indian Ocean in the year 2004 is still considered as the most upsetting tsunami taking more than two hundred thousand lives. Tsunamis are quite rare in occurrence as compared to other natural disasters, but they are equally damaging.
During the eruption of a volcano on land, debris falls with a great thrust into the water body, causing the same ripple effect. Volcanoes can be underwater as well. All earthquakes do not cause tsunamis.
There are four conditions necessary for an earthquake to cause a tsunami:
- The earthquake must occur beneath the ocean or cause material to slide into the ocean.
- The earthquake must be strong, at least magnitude 6.5 on the Richter Scale.
- The earthquake must rupture the Earth’s surface and it must occur at shallow depth – less than 70km below the surface of the Earth.
- The earthquake must cause vertical movement of the sea floor.
The saddest effect of a tsunami is the loss of lives in huge numbers. Tsunamis hit suddenly, with almost no warning and hence people get no time to escape it or run away. They drown, collapse, are electrocuted, etc. Tsunamis not only cause massive destruction of life but also degrade the environment in a gigantic way. In order to prevent Tsunamis, the government can invest in building strong and high protective infrastructure which can withstand the force of a tsunami. The length should be so tall, that the most upper wave of the tsunami cannot over top it. We need to educate people and make them aware of the effects and impact of a tsunami is exceptionally crucial. (The author is a freelance writer, journalist & a cartoonist. He can be reached at email@example.com)