What makes a trending topic a trending topic?

[bug_vicho]

Hi everybody. I’m making an app that use trending topics to show an alert about differents natural dissasters in my country. Thats why I’m asking myself , whats the parameter that makes a trending a trending?
I need to know wich is the exact determination in this matter like an algorithm that show whats the specific amount of tweets makes it a normal one, a medium one or a trending topic.
Greetings

[andypiper]

There are a combination of factors including Tweet volume. We do not publish the specifics of this algorithm, but you can read more information on the support pages.

[bug_vicho]

Thanks Andy. I really dont need the algorithm, I realize that its a comibination of factors, but if you can summarize a tweet in an amount of numbers what will be the specific amount to determine if its normal one (low amount of RT or likes), a medium one or a trending topic.
Thanks again