Well...most fireworks factories don't stock 15 to 480 tons of TNT at one locale...in addition, a surface blast may not likley produce as much initial ground signal to register on the seismo's
...so I'll have to say earthquake this time round....

The date is centered around the 4th yes...I noticed that someone else pushed their dates to a few days after the 5th.... So I was wondering what theory they were using...( maybe similar to mine).

Anyway, guess we'll be finding out if it's a July 4th event or not....