'tsunami'/"tsunami"

[Odessa Dawn]

Op-ed: Islamist 'tsunami' will sweep through entire Middle East unless Israel, Arab neighbors act now

More: Seize opportunity to stop radical Islam - Israel Opinion, Ynetnews


Furthermore, given that even under the best medical conditions 40,000 Iranians lose their lives to cancer every year, and that it has been predicted by many medical experts that Iran will have a "cancer tsunami" by 2015 as every year 70,000 to 80,000 new cases of cancer are identified in Iran, the gravity of the situation becomes even more perilous.

More: The unfolding human catastrophe in Iran that Obama boasts of creating

What does tsunami mean in the underlined parts? According to the above texts, does it mean catastrophe as being stated in dictionaries or a large number/large numbers? By the way, why is tsunami being enclosed with double/single inverted comma?

[SlickVic9000]

(Not a Teacher)

A tsunami is simply a very large wave. The story is trying to evoke the image of a massive 'wave' of Islamists sweeping across the Middle East. The use of the term 'tsunami' here, and the attendant connotations of natural disaster, is quite intentional.

[nouamaneer]

and as for the use of inverted commas to enclose the underlined phrases, it simply signals an unusual use of the word and that s one of the functions of quotation marks.