Geomedia: Twitter gives heads-up to users and officials about earthquakes

Twitter stirs up a wide range of reactions — it’s hailed as a vital social networking service by some, despised as the ultimate waste of time by others. But the popular online message board does possess one characteristic that is universally undeniable: speed.

That speed caught the attention of scientists at the U.S. Geological Survey (USGS), who noticed Twitter’s ability to outpace even news organizations at reporting natural disasters. The agency sees Twitter as a way to distribute scientific information quickly to people. But it also believes Twitter’s benefits could extend in the other direction: helping the agency detect quakes that would have otherwise taken much longer to pick up.

Twitter is a free Web site on which users post messages of 140 characters or shorter, called tweets, on their profile page. Those messages are automatically forwarded to people who have subscribed to, or follow, that profile. Like many organizations, USGS has taken advantage of the site to promote its work. The agency now has six Twitter profiles, including USGSted, or the USGS Twitter Earthquake Detector.

Started in May 2009, USGSted uses a prototype computer system that collects information on earthquake tweets around the world, says Paul Earle, a geophysicist at the USGS National Earthquake Information Center in Golden, Colo., who is in charge of the project. The system, which Earle described this week in a presentation at the American Geophysical Union's fall meeting in San Francisco, Calif., continuously catalogs any tweets that mention the word “earthquake” or earthquake-related words such as tsunami (also searching multiple languages). It then estimates the geographic location of the tweets based on the users’ associated bios. USGS scientists then compile this information to create their USGSted tweets describing the event.

USGSted tweets often include a link to the official USGS report of the event, a map pinpointing where related tweets came from, and occasionally even the number of related tweets that came up per minute.

For example, one recent USGSted tweet read:
“Moderate quake NEW ZEALAND Dec-08 22:09 UTC, 10.6 quake-tweets/min, tweet map: http://twitpic.com/sq2em info: http://bit.ly/5UCvoz.”

Twitter might also help USGS detect smaller quakes that might otherwise take weeks for the agency to notice. Although USGS maintains some 2,000 seismic stations that can pick up most earthquakes of magnitude 5.5 or larger within 20 minutes, smaller quakes can avert immediate detection. A flutter of Twitter activity could alert USGS scientists to those quakes, revealing when Twitter users feel a smaller quake worth checking out, Earle says.

Take the magnitude-4.4 earthquake that hit Iceland in June 2009: Earle was watching the computer system when it started picking up a bunch of related tweets coming from the capital, Reykjavik. After realizing that USGS had not received enough data from the seismic stations in its global network to officially report the event, USGS scientists retrieved additional information from Iceland’s own seismic network and reported the earthquake on the official USGS site. “That particular quake might not have been reported by the USGS until weeks after because it was small enough that it would not have been automatically detected by our global system,” Earle says.

All of this tweeting could also help USGS focus its reportage on earthquakes, Earle says. “[The center] reports about 30,000 earthquakes per year … Nobody’s going to want to hear about 30,000 earthquakes per year on their Twitter account, so you can use Twitter as a way of filtering out the quakes that people on Twitter would be interested in hearing about.”

USGSted still has some bugs that need to be worked out, Earle says. It has to contend with “noise” problems — tweets about songs that contain the word “earthquake,” for example — as well as how to pinpoint exactly where relevant tweets are coming from (“at the beach” doesn’t narrow things down too much).

Earle notes that Twitter won’t likely change the way USGS monitors seriously damaging earthquakes: “I don’t see that you are ever going to be shutting down a nuclear power plant based on tweets.” But in general, he says, people are interested in hearing about the smaller earthquakes that they do feel — and with the help of Twitter, USGS might be able to spread the message about those quakes faster.

Brian Fisher Johnson
Tuesday, December 15, 2009 - 22:00