Scientists around the world use an earthquake monitoring system that can relay information faster than seismometers: people with smartphones and Internet connections. When earthquakes hit anywhere in the world, visitors hit the Web, seeking information. Their site visits, tweets, and social media posts, in turn, provide seismologists with valuable information about the propagation of earthquakes.
“Twenty years ago, when I was a student, we knew an earthquake was felt because all the phones were ringing,” said Rémy Bossu, a seismologist at the European-Mediterranean Seismological Centre (EMSC). “Today the people are just turning to the Internet.”
EMSC is just one organization taking advantage of a plugged-in public to monitor earthquakes. The U.S. Geological Survey (USGS) also has multiple projects around the country tracking earthquakes via human means. These projects may one day help seismologists develop better strategies to alert communities that seismic energy from a recent rupture is headed their way, Bossu said.
Speed of Social Media Rivals Speed of Earthquake Signal
During his talk at the 2015 meeting of the American Association of the Advancement of Science, held in San Jose, Calif., Bossu discussed a case study: the 5.8-magnitude earthquake that rocked Virginia and the surrounding areas on 23 August 2011.
Soon after the quake, about 148,000 people reported feeling shaking, using USGS’s “Did You Feel It?” website. On top of that, Bossu and his colleagues reported that visitors inundated EMSC’s website so quickly and consistently that a discernible uptick in hits to the website followed the propagation of the seismic waves by only a 90-second lag.
EMSC scientists approach citizen seismology from multiple angles, Bossu said. Those experiencing an earthquake can fill out questionnaires on EMSC’s website, they can follow the center’s Twitter account, or they can use the center’s mobile app to quickly upload real-time thoughts and images.
It’s not necessarily the magnitude of the earthquake or its epicenter that the public cares about, Bossu added. It’s the level of shaking, where the earthquake is propagating, and how motion is affecting the larger population.
Within 30 seconds of a felt earthquake anywhere in Europe, EMSC scientists now detect a traffic surge on their website, with information from seismometers following about 60 seconds later, Bossu said. Scientists then track IP addresses and quickly turn incoming data into valuable information—such as a breakdown of where damage has occurred—for those who visit the EMSC website and follow the EMSC Twitter stream. For instance, if an area hit by an earthquake suddenly goes offline, this might be indicative of severe damage, Bossu said.
Citizens can also upload geotagged pictures of damage to help shorten response time from local authorities. As EMSC’s technology improves and more people participate, feeds of tweets and responses to questionnaires in real time may help first responders, relatives, and other people outside affected regions get a feel for damage, neighborhood by neighborhood.
“We have created, basically, a virtuous circle,” Bossu said. “We collect information that we use then to improve information to the public.”
Other Citizen Seismology Projects
USGS has a similar approach, taking advantage of the world’s obsession with Twitter to track the propagation and damaging effects of earthquakes.
USGS employs a system that monitors Twitter for any mention of the word “earthquake” in English and 32 other languages. These tweets are often the first indication that an earthquake has even occurred, said Paul Earle, a seismologist at USGS and the director of operations for the National Earthquake Information Center. Nearly 8% of the world is on Twitter, which means that even in remote areas not extensively networked with seismometers, Twitter users might provide a first alert to ground motion.
USGS’s Quake-Catcher Network aims to understand earthquake propagation in the United States by having volunteers install low-cost seismometers externally on desktop computers or internally in their phones or laptops. The sensors can also be installed in schools and other buildings to monitor infrastructure.
Once the internal smartphone technology is sensitive enough, Bossu said, seismologists may be able to implement early warning systems to better prepare a population for the seismic waves headed their way. These extrasensitive seismometers would pick up the signals from an incoming earthquake wave and immediately send a digital warning to the surrounding area, giving those tapped into such warning systems precious extra seconds to prepare.
A Digital Nervous System
In America, 74% of adults use social media. These numbers are steadily increasing globally, and 3 billion people are predicted to be online by the end of this year. This digital population offers seismologists a vast network of eyewitnesses with a strong desire to share their experiences online.
“You can count the Internet as a digital nervous system of our planet,” Bossu said. “You just plug it in and look at how the people react when an earthquakes strikes.”
—JoAnna Wendel, Staff Writer
Citation: Wendel, J. (2015), Internet users act as earthquake trackers, Eos, 96, doi:10.1029/2015EO025457. Published on 2 March 2015.