The Trembling Earth

now at

Twitter and the 21st century earthquake

You thought seismic waves were fast… you should see Twitter! The social microblogging service increasingly serves as a communication conduit between emergency management agencies and individuals during crises. The USGS has begun to exploit Twitter, both to dispatch earthquake information and in turn to collect tweets that show an earthquake has occurred, potentially before the relatively sparse network of seismometers detects and reports it. A couple of years ago USGS scientists Paul Earle, Michelle Guy, and their colleagues reported their preliminary evaluation of a system that culls tweets containing the word “earthquake” from the vicinity of a known quake epicenter. The results were strikingly effective at highlighting the epicentral region of the quake, indicated by the largest jump in the frequency of “earthquake”-related tweets. Their article is publicly available and explains the benefits and drawbacks of a Twitter-based earthquake detection system. It’s well worth a read. OMG Earthquake! Can Twitter Improve Earthquake Response? The article contains perhaps my favorite sentence of any academic paper I’ve read:

The first geocoded tweet about the earthquake arrived 19 seconds after the origin time and reported omfg, earthquake.”

Their supplemental material makes for an entertaining read, listing 360 seconds of tweets containing “earthquake” that followed the 2009 M4.3 Morgan Hill quake in the Bay Area. Electronic Supplement to Earle et al., 2010 While thoroughly exploring the caveats of twitter quake detection such as the general lack of true shaking records, including the fact that shaking intensity is unreported or unreliable, the authors demonstrate the powerful comparison of Twitter response times to the average reporting delays of even our fastest instrumental networks. Whereas tweets are published with a lag time of ~5 seconds, official USGS earthquake solutions are only made available minutes after an earthquake. Commonly in disasters, small data transmissions via mobile devices offer the only functional way to disseminate information, since power and telephone lines may be disrupted and data-heavy voice calls may overwhelm cell networks. Many people on both coasts may have a familiar experience in mind following moderate earthquakes: even with light shaking and no damage, the excitement stirred up by a temblor results in an overloaded cell network incapable of supporting your phone calls. It can be hours before phone calls go through.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: