According to seismologists from the University of Washington, Seattle Seahawks fans created their second documented earthquake in just a few years. It happened during their playoff victory over the New Orleans Saints on January 11, 2014.
I had written about this possibility before the game on the koin.com weather blog. Read that post here, plus follow the links to see the actual quake on the electronic seismograph!
I also wrote about how weather could possibly impact the game–and it sure did on quite a few plays.