Just below the surface of earth – lie huge sheets of rock called as ‘tectonic plates’ that are about 70 kilometers thick. These plates move a few centimeters ( an inch or two) producing distortions with the surface. When these distortions get large enough, natural forces try to correct them by themselves causing the plates to move suddenly. When this happens, earth shakes resulting in earthquakes!! And the worst is – if these distortions take place deep under the ocean – it causes tsunami waves, some of them are 20 feet tall – they are shallow waves, and move at the speed of 700 km an hour, gobbling whatever comes in the way – devastating material, men, communities!!
‘A tsunami (pronounced su-nah-me) is a wave train, or series of waves, generated in a body of water by an impulsive disturbance that vertically displaces the water column. Earthquakes, landslides, volcanic eruptions, explosions, and even the impact of cosmic bodies, such as meteorites, can generate tsunamis. Tsunamis can savagely attack coastlines, causing devastating property damage and loss of life.’
Look at the fact that – Japan as a country – is land/earth ‘sitting’ on the edge of five such tectonic plates and is prone to earthquakes all the time ( just like California is too!) But, let us look at the brighter side – the high rise buildings in Japan, especially in the coastal area – are best prepared to meet such eventualities – here, strict building codes apply!! Japan, after the ‘Kobe earthquake’ in 1995 has put in force great precautions and has spent extensive resources to ensure minimum damage happens! Japan has outfitted buildings with advanced devices called base isolation pads and energy dissipation units to dampen the ground’s shaking during an earthquake. The country that gave the world the word ‘tsunami’ built concrete seawalls, some as high as 40 feet – as a first line of defense against the water. There are network of sensors placed/ set up to send immediate alarms to others – so as to caution other susceptible locations in the coastal area! Japan is well prepared; if it was India – I cannot imagine what would have happened. Mumbai is collection of islands (seven in all) and most of today’s Mumbai is ‘reclamation area’- i.e., sea filled with junk material to gain extra land – huh! if there is a earthquake/ tsunami in the Arabian Sea – most of Mumbai will be gobbled up! No other country is as well-prepared as Japan is!