A 7.8 magnitude earthquake struck Myanmar on March 28, claiming over 5,000 lives and causing widespread damage in neighboring countries. The epicenter of the quake was along the Sagaing Fault, which runs north-south through the country.
Seismologists have confirmed that the southern part of the rupture took place at extremely high speeds, up to 3.1-3.7 miles per second – a phenomenon known as supershear velocity. This likely contributed to the earthquake’s devastating impact.
When an earthquake occurs, seismic waves travel at different speeds. P waves compress materials but cause little damage, while S waves cause destructive perpendicular motion. However, when parts of an earthquake’s fault rupture at supershear velocity, it means that the speed of the break is faster than its S waves.
The Sagaing Fault experienced a 298.3-mile (480 km) long rupture, with significant movement near Mandalay and less intense movement further south. Scientists believe this unusual movement contributed to the widespread damage.
Seismic data from a station near Nay Pyi Taw showed clear signs of supershear rupture, including a sudden displacement of ground along the fault. Experts suggest that this speed and direction may have caused much of the destruction.
While scientists can’t predict earthquakes with precision, research has shown that earthquake early-warning systems can provide crucial last-minute warnings before an event strikes. The Android Earthquake Alerts (AEA) system, for example, has been proven to be as efficient as traditional seismic networks in detecting incoming events.
Source: https://gizmodo.com/myanmars-devastating-earthquake-in-march-split-the-earth-at-supershear-velocity-2000632109