[Rockhounds] Scientists find telling early moment that indicates a coming megaquake

[Kreigh Tomaszewski]

Scientists combing through databases of earthquakes since the early 1990s
have discovered a possible defining moment 10-15 seconds into an event that
could signal a magnitude 7 or larger megaquake.

Likewise, that moment—gleaned from GPS data on the peak rate of
acceleration of ground displacement—can indicate a smaller event. GPS picks
up an initial signal of movement along a fault similar to a seismometer
detecting the smallest first moments of an earthquake
<https://phys.org/tags/earthquake/>.

Such GPS-based information potentially could enhance the value of
earthquake early warning systems, such as the West Coast's ShakeAlert, said
Diego Melgar, a professor in the Department of Earth Sciences at the
University of Oregon.

https://phys.org/news/2019-05-scientists-early-moment-megaquake.html