Twitter Inc., the microblogging service that lets more than 140 million users send short messages on everything from the mundane to the life-altering, tipped off the U.S. Geological Survey to the 7.6-magnitude earthquake that hit near the coast of the Philippines today.
The Reston, Virginia-based agency detected tweets about the earthquake one minute and seven seconds after the seismic event, which occurred at about 8:47 p.m. local time, Paul Earle, a USGS seismologist, said in a telephone interview.
Social media sites such as San Francisco-based Twitter are playing a more prominent role in raising awareness of and coordinating responses to natural disasters, including the 2010 earthquake in Haiti and one last year in Japan that led to the failure of the Fukushima nuclear plant. USGS scientists monitor tweets for mentions of the word "earthquake" and its equivalents in other languages.
"In some cases, it gives us a heads up that it happened before it can be detected by a seismic wave," Earle said.
The system for monitoring Twitter, called the Tweet Earthquake Dispatch, is most effective in remote regions, where the agency does not have as many instruments for measuring seismic activity as it does in an earthquake-prone area such as California, Earle said.
A tsunami alert was canceled after being issued on the heels of the temblor. The Philippines has been battered by natural disasters in recent months, killing dozens of people. President Benigno Aquino has drawn criticism for his handling of the crises. The nation was hit by an earthquake that killed at least 48 people and triggered landslides that left dozens more missing in February.
Organizations such as Oxfam International and American Red Cross post on the site to coordinate relief efforts, while families can use Twitter to search for missing loved ones.
The USGS occasionally receives false alarms from its prototype system, such as when Twitter users post messages about the song "Earthquake" by British musician Labrinth.
"It's not foolproof," Earle said.