What Causes a Tsunami

Tsunami is a seismic sea wave that is often caused by earthquakes, when the tectonic plates beneath the ocean floor collide with each other. These earthquakes may sometimes not cause a tsunami themselves, but may subsequently lead to it as a result of the oceanic landslide that occurs as a result of the initial earthquakes. These landslides cause huge masses of water to rise above the surface line, which often get further aggravated as a result of forming into giant waves within the shallow waters of shorelines. The third cause of tsunamis are volcanic eruptions.

Oceanic Earthquakes

Oceanic earthquakes are by far the most common causes of tsunamis. The reason being that there are tectonic plates under the earths surface. Those that are situated under the ocean floor sometimes rub against each other or collide against one another which causes a lot of energy to disperse. This heat and energy thereby causes the water to rise as a result of the pressure exerted from below. To make it clearer, what actually occurs during an under ocean earthquake is that the heavier tectonic plates try to slide their way through, from under the lighter tectonic plates. These plates are basically made up of condensed rock like matter that move along the asthenosphere which is a partially molted, weaker version as compared to mantle. The tectonic plates are also known as the litospheric plates that move along over the asthenosphere.

Tsunami occur because, while the heavier plate tries to slide beneath the lighter one, it may end up getting stuck which leads to massive pressure being built up between the two plates as the heavier one pushes the lighter plate sideways and downwards. What happens next is that the lighter plate reaches its limit of being pulled downwards, it suddenly snaps back up to its original surface area which causes the pressure to explode upwards. This pressure pushes the water upwards, which forms into a humongous wave.

The Ring of Fire

Tsunamis can be so powerful that they can travel over many thousands of kilometers just so as to crash at the shores. Most tsunamis occur in the pacific ocean which is the biggest water body on earth. It covers 1/3 rd of the earths surface area, and is surrounded by deep oceanic trenches, island arcs and mountainous landscape. That is why this area is often called the 'Ring of Fire' because it is prone to earthquakes.

With about 2/3 rd of the world being ocean, the consequences of a strong oceanic earthquake can be catastrophic. An example of the effects of tsunami, being the Christmas tsunami that hit the Indian ocean in 2004. The fact being that the earthquake occurred from the islands of Sumatra, and the magnitude of the earthquake was a massive 9.2 on the Richter scale. This earthquake caused a string of tsunamis that swept across Indonesia, India, Madagascar as well as Ethiopia! This tsunami was the worst ever, it claimed the lives of more than 283,000 as well as completely destroyed the landscapes, the buildings and all standing objects.

Hopefully, now you know more about tsunamis and why they take place. The other ways in which a tsunami can occur is due to a meteoric impact and due to man-made phenomena such as nuclear testing of weapons under water in the ocean. Scientists have not yet come up with a way to prevent tsunamis from occurring, though certain measures have been taken that allow us to predict as to if a tsunami is approaching a specific group of areas through satellite identification and reading of oceanic waves.