Tremors generate tweets in new USGS earthquake program

The U.S. Geological Survey is testing the use of Twitter as a means to quickly collect and disseminate earthquake-related information. The popular social networking Web site and blogging tool is being used as a means to gather firsthand accounts of seismic events as they unfold.

Funded by the American Recovery and Reinvestment Act, the Twitter Earthquake Detector (TED) program is an “exploratory effort” intended to gather real-time earthquake-related messages, according to USGS. The idea is to have people who actually feel a tremor or observe its effects to tweet their observations.

The TED system applies location, time and keyword filtering to track accounts of tremors. The system allows for first impressions and even photos of the event to be delivered to the public from within or near the quake’s epicenter prior to any official report.

“Many people use Twitter, so after an earthquake, they often rapidly report that an earthquake has occurred and describe what they’ve experienced,” said Paul Earle, a USGS seismologist. “Twitter reports often precede the USGS’s publicly released, scientifically verified earthquake alerts.”

TED monitors Twitter for tweets that contain the word “earthquake” in all languages. The system also queries Twitter after USGS or another contributing network to the Advanced National Seismic System detects an earthquake, Earle said.

The TED program is intended to augment rather than replace other USGS earthquake projects that rapidly detect and report earthquake locations and magnitudes in the United States and globally. Tweets typically provide the initial information to the public faster than official scientific alerts, which can take between two and 20 minutes, depending on the location of the event. The program has great potential, particularly in areas where seismic instrumentation is sparse, USGS said.

“In densely instrumented regions, like California, locations and magnitudes are produced within two to three minutes of an event,” said Michelle Guy, a USGS scientist and software developer. But the “time increases up to 20 minutes in sparsely instrumented regions.”

“Analyzing the tweets provides an early indication of what people experience before the quantitative information” is analyzed and delivered, Guy said.

However, USGS, which publishes the location and magnitude of about 50 earthquakes a day, cautioned that tweets should be viewed as a preview and supplement to the official report. Twitter-based accounts are admittedly anecdotal and could even prove to be false positives.

“The basic difference is speed versus accuracy,” Guy said.

The tweets are subsequently attached to the official earthquake alert and report with a summary of the cities and an interactive map showing their origin. The tweets are open to the public to search and analyze. The program may be reviewed at twitter.com/USGSted as well as www.USGS.gov/socialmedia.

Earle said people are integral to the success of the TED program. “Without their tweets, we would have no system,” he said.