What is Catastrophic Implosion ?

Catastrophic Implosion 

On the contrary of explosion, an implosion occurs when an object collapses in on itself within a few milliseconds. In explosion an object breaks up due to outward pressure, but, in implosion, an object breaks up due to inward pressure. The submersible named, Titan, operated by OceanGate is said to have destroyed due to catastrophic implosion in the North Atlantic Ocean en route to see the wreckage of  Titanic ship that sunk in the ocean in 1912. 

More to understand    

Titanic wreckage is at the depth of 4000 meters (4km) below the surface of the ocean. While, atmospheric pressure at the surface of the ocean is 14.7 pounds per square inch (psi) or 100 kilopascals, at the depth of 4000 meters below the surface, the water pressure is considered around 6000 (psi) or 41,000 kilopascals. Under such a huge pressure, even a minute structural flow would cause catastrophic implosion.  

Why is it in news ?

    Recently five people including the British billionaire explorer Hamish Harding, UK citizens Shahzada Dawood and his 19-year-old son Suleman Dawood, French national Paul-Henri Nargeolet and OceanGate Expeditions chief executive Stockton Rush had embarked on an expedition to see the wreckage of ship Titanic that sunk in 1912 in the North Atlantic ocean in which over 1,500 people on board died. En route all the five voyagers died when the submersible named Titan which they were boarding met with catastrophic implosion below 1600 feet from the surface of the ocean.