14 December 2009

Twitter Helps Scientists Locate and Assess Earthquakes!

Posted by Michael McFadden

Ever been in an earthquake? I have twice—both times my heart was in my mouth as the ground pitched and rolled and I scrambled for cover. The first was a tiny one in the Pacific Northwest, the second was the 1999 Hector Mine earthquake.The latter was intense—though I was in L.A., I could feel the surface rock the dorm room bunk bed I was perched on like a roller coaster.After that earthquake, my friends and I immediately went online to see what had happened where. We viewed beach-ball diagrams, saw the epicenter. It was amazing—the event had just happened, and within minutes data became available.

That was then. Now, when an earthquake happens, it has become a standard practice for people to go to a page on the USGS’s site and post whether they felt a given earthquake and what it was like! This “Did you feel it” interactive feature allows scientists to quickly get a feel of the scope, intensity, and effects of an earthquake.


A USGS “Did you feel it” plot for the 6 April 2009 L’Aquila earthquake in Italy. Warm colors represent that visitors to the site felt the earthquake more intensely

Building on this, scientists are now trying to see whether Twitter can improve earthquake responses.

USGS representative Paul Earle, speaking at a Monday morning press conference, noted that “people like to tweet after an earthquake.” Through a prototype model that monitors Twitter for the word “earthquake,” synonyms to “earthquake” in English, and translations of “earthquake” in other languages, scientists can use Google to locate where the tweets were posted. These get sent to a database that collects these firsthand accounts of ground motion.  From this, Twitter accounts can be compared with standard earthquake e-alerts of position and magnitude

The eventual goal of this is to improve hazard and risk assessments. There is a window of time between when an earthquake is felt, and when it is scientifically confirmed, notes Earle.  “This can be from 2 minutes to 20 minutes, depending on where you are.”  However, if Twitter indicates that many people have felt an earthquake, scientists can begin producing “Community Internet Intensity Maps” (CIIMs), which can provide a quick assessment of the scope and damage of any given earthquake.

Beware of errors and false positives, says Earle. A tweeter might report an earthquake in Ontario—but do they mean Canada or California?  And apparently, 24/7 gamers like to tweet about their awesome frags on the first-person shooter Quake. Others tweet that the DQ Oreo Brownie Earthquake is tasty. I’m sure it is!

–Mohi Kumar, AGU Science Writer