When it comes to the most destructive earthquakes on Earth, a few extra moments of warning could spell a huge difference in saving lives.
New research reveals a specific point 10 to 15 seconds into an earthquake event when geologists may be able to identify a particularly massive earthquake known as a megaquake. It may only buy people additional several seconds of time before the peak of a quake hits, but every second really counts in the wake of potential disaster.
A Potential Moment Predicting Massive Quakes
In a new study published in the journal Science Advances, scientists analyzed GPS data on the peak acceleration rate of ground displacement. They combed over data since the early 1990s, discovering a defining point in time when an earthquake transitions into a "slip pulse," which has mechanical properties signaling magnitude.
This defining moment emerges about 10 to 15 seconds into an event and could signal a pending earthquake with a magnitude of 7 or higher.
Similar trends were found in different databases from the United States, Europe, and China, all of which combine to provide data on over 3,000 earthquakes. The telltale signs of displacement acceleration were identified in the first 10 to 20 seconds of 12 major earthquakes that occurred from 2003 to 2016.
"To me, the surprise was that the pattern was so consistent," said study author Diago Melgar, who is a professor at the University of Oregon, in a statement. He added that it was nice to see the patterns appearing similarly across the databases even if they were made in very different ways.
Using GPS To Monitor Quakes
GPS is already being used to monitor plenty of land-based faults around the world, but it's not as frequently used when it comes to real-time hazard monitoring due to its telltale delay.
"As an earthquake starts to move, it would take some time for information about the motion of the fault to reach coastal stations," Melgar explained. "That delay would impact when a warning could be issued. People on the coast would get no warning because they are in a blind zone."
He added that the delay could be eliminated by placing sensors on the seafloor so scientists could detect the early acceleration behavior. In doing so, early warning systems could be improved greatly.
In 2016, Melgar spearheaded a study that showed how existing GPS instruments could be used to add an extra 20 minutes of warning of a possible tsunami.
