Great catastrophes as stray events or series of destructive occurrences befalling on this earth are merely not called ‘Pralaya’. ‘Pralaya’ causing processes have relations with time. The present period is ‘Time of Pralaya’, whose possibility of continuation is supposed to be minimum upto the end of this century, during which there is possibility of destruction of human population. 

There are two types of ‘Pralaya’: ordinary and ‘Great Pralaya’ (disasters). In ‘Great Pralaya’, there is expectation of the destruction of even the whole earth, whereas in ordinary ‘Pralaya’ there is no such possibility. It is not possible to avert ‘Mahapralaya’, whereas  it is possible to avert ordinary ‘Pralaya’ wherein there is possibility of  destruction to a  great extent. But this aversion is possible only through right means (see page no. 7).