First, I created this word cloud from tweets which included the #emeraldgate tag. (Placement of the words doesn't matter, only the size. The larger the word, the higher its frequency.) As you can discern in a glance, the retweet (RT) is what fueled the explosion, sparked by a handful of originators whose tweets were RT'd by a larger pool of participants. A textbook case of the power of the social network. You can click through for a larger image.

The second visualization is from a wild site called "IS Parade" which creates an animated parade from a Twitter user name or text phrase, including tweeps and tweet excerpts. It really gets across the crowdsource roots of the #emeraldgate meme.