Miguel Rios, an engineer at Twitter, created this visualization of earthquake-related Tweets as they rippled across the country in the first 30 seconds after the quake on August 23rd, 2011.
According to web comic xkcd, tweets have the potential to travel faster than seismic waves, eventually overtaking them 100 km from the epicenter of the quake. Is it possible that a tweet from Washington could have traveled to New York fast enough that someone could have read it before they felt the tremors?
Rios also created beautiful visualizations of tweets after the earthquake in Japan, which you can see on Twitter's blog.
Follow Miguel Rios on Twitter: @miguelrios.