Imagine if smartphones could help warn a population against an earthquake. That concept might be closer to reality thanks to new research, which suggests phones and other electronics can serve as early warning systems for large quakes.
Scientists at the U.S. Geological Survey (USGC) have realized that GPS receivers in smartphones might come in handy during earthquakes. How? Because they are capable of detecting permanent ground movement (also known as displacement) caused by fault motion.
Crowdsourcing observations
The team used crowdsourced observations from the participants’ smartphones to detect earthquakes and then notify the cellphone users. "Crowdsourced alerting means that the community will benefit by data generated by the community," said the study’s lead author, USGS geophysicist Sarah Minson.
Minson and her fellow researchers say their technique could function as an earthquake early warning system. These systems are capable of detecting earthquakes and quickly transmitting that information to at-risk residents. Countries such as Japan and Mexico have intricate warning systems, but many developing countries do not.
"Most of the world does not receive earthquake warnings mainly due to the cost of building the necessary scientific monitoring networks," added geophysicist Benjamin Brooks.
Detecting magnitude seven earthquakes
According to the researchers, smartphone sensors can detect and issue warnings for magnitude seven earthquakes or larger ones. However, they cannot do the same for smaller quakes, which can cause serious damage as well. The researchers tested the feasibility of their system by using a simulation of a hypothetical earthquake and real data from the 2011 magnitude 9 Tohoku-oki quake. They concluded that it takes a small amount of a population (for example, 5,000 people in a large city), for the system to efficiently detect and analyze the data, and send a warning to farther-away areas.
"The speed of an electronic warning travels faster than the earthquake shaking does," said Craig Glennie of the University of Houston.
"The U.S. earthquake early warning system is being built on our high-quality scientific earthquake networks, but crowdsourced approaches can augment our system and have real potential to make warnings possible in places that don't have high-quality networks," Douglas Given, USGS coordinator of the ShakeAlert Earthquake Early Warning System, explained.
Pilot project testing the warning system
A pilot project funded by the U.S. Agency for International Development, in collaboration with Chile’s Centro Sismologico Nacional, is in development stages. It will test a hybrid earthquake warning system that utilizes both smartphone sensors and professional ones.
"Thirty years ago, it took months to assemble a crude picture of the deformations from an earthquake,” said Thomas Heaton, a Caltech professor of engineering seismology. “This new technology promises to provide a near-instantaneous picture with much greater resolution.”
Source: NASA Jet Propulsion Laboratory