A recent video of a magnitude 7.7 earthquake in Myanmar has revealed new insights into the behavior of fault lines during seismic events. The footage captures the ground cracking and moving in a curvy path, a phenomenon previously only observed through geological records and “slickenlines” – scrape marks on the sides of faults.
Geophysicist Jesse Kearse, who analyzed the video with his colleague Yoshihiro Kaneko, was astonished by the movement’s curvature. According to Kearse, the crack initially curves downward before accelerating to a peak velocity of 10.5 feet per second and slipping 8.2 feet in just 1.3 seconds.
The researchers suggest that the curvature is caused by uneven stresses on the fault at different depths. The surface stress is lower than the deeper stress, resulting in an off-course movement. This, in turn, leads to a curved motion as the fault “catches itself” and corrects its path.
Understanding the dynamics of these curvatures can provide valuable information about past earthquakes and help scientists predict future ground ruptures. The study was published recently in The Seismic Record journal.
Source: https://www.livescience.com/planet-earth/earthquakes/first-video-of-an-earthquake-fault-cracking-has-revealed-another-surprise