(ORDO NEWS) — Geophysicists at the University of California have found that powerful supershear earthquakes, once considered rare, have become much more common.
Scientists analyzed all impact earthquakes of magnitude 6.7 or more around the world since 2000 – there were 87 in total – and identified 12 supershear earthquakes, which accounted for 14% of the total.
This percentage is more than double what scientists expect: so far, less than 6% of shear earthquakes have been identified as supersonic.
A supersonic earthquake is an earthquake in which a rupture propagates along the fault surface at velocities that exceed the speed of a seismic shear wave (S-wave).
This causes an effect similar to a sonic boom. As a result, such earthquakes are potentially more destructive than others of the same magnitude.
The study also showed that supersonic earthquakes occur just as frequently under oceans as they do on land, and that they most likely occur along shear faults such as the San Andreas Fault.
The findings suggest that disaster planning efforts should consider whether nearby faults are capable of triggering supershear earthquakes.
Where possible, authorities should take steps to prepare for a higher level of potential harm.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.