Scientists from the United States have presented a new method for measuring the level of potential earthquakes using a GPS system. It can save hundreds of thousands of people.
The researchers explained that the GPS-based global earthquake monitoring system can provide more timely and accurate warning of powerful earthquakes than traditional seismic networks. It can also reduce the frequency of false alerts.
In a new study published in the Bulletin of Seismological Society, the research team detailed a new process for developing a global earthquake warning system that measures the displacement of Global Positioning System (GPS) satellite receiver stations when an earthquake deforms the earth’s crust. The system estimates the severity of an earthquake within seconds and issues warnings in less than two minutes from the first ground movement is detected.
According to lead study author Timothy Melbourne, professor of geology at Central Washington University, a GPS-based detection system can provide earlier and more accurate alerts than traditional seismic sensors installed in tectonically active regions. They may fail due to a burst of data when seismic waves first appear.
“The problem is that when earthquakes get very strong, it is very difficult for seismic networks to understand what happened in the first minutes after the event,” the researchers noted. “Even with a moderate earthquake, there is a very complex seismic trace. Seismic waves are emitted into the earth, they are reflected inside the earth and interact with structures. It is very difficult to determine what was the source of the waves and what was the result of reverberations in the earth’s crust. ”
Seismologists usually wait for the waves to propagate further from the center, and estimate the earthquake from afar. But in some cases, in the face of the threat of highly magnetic earthquakes and potentially devastating tsunamis that can kill thousands of people, this is not possible.
For example, in 2019, the American earthquake warning app ShakeAlert failed to alert Los Angeles residents to the 6.4 magnitude earthquake that struck Southern California on Independence Day because it misjudged the severity of the tremors. However, false alerts can provoke panic and reduce the credibility of traditional systems in the future.