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Uploaded on Aug 24, 2011
Inspired by http://xkcd.com/723 and described at http://www.iq.harvard.edu/blog/netgov... -- A heat map of the frequency of tweets mentioning the word "earthquake" in the 5 minutes after the Virginia earthquake on 08/23/2011. The locations are self-reported by Twitter users and may be erroneous. The spread of the earthquake is approximated to be 4000 m/s.