A recent earthquake in Myanmar has provided scientists with a rare and groundbreaking discovery – direct visual evidence of curved fault slip. The finding was made possible by a security camera video taken during the magnitude 7.7 earthquake, which showed the dramatic fault movement.
Geophysicist Jesse Kearse and his colleague Yoshihiro Kaneko at Kyoto University analyzed the video more carefully and concluded that it had captured the first direct visual evidence of curved fault slip. Until now, there has been no visual proof of the curved slip that might create slickenlines, which are scrape marks created by blocks of rock moving past each other during faulting.
The researchers used pixel cross correlation to measure the rate and direction of fault motion during the earthquake, finding that the fault slipped 2.5 meters for roughly 1.3 seconds at a peak velocity of about 3.2 meters per second. This shows that the earthquake was pulse-like, confirming previous inferences made from seismic waveforms of other earthquakes.
Most of the fault motion is strike-slip, with a brief dip-slip component. The slip curves rapidly at first, as it accelerates to top velocity, then remains linear as the slip slows down. The pattern fits with what earthquake scientists had previously proposed about slip curvature, which might occur in part because stresses on the fault near the ground surface are relatively low.
The discovery can help researchers create better dynamic models of how faults rupture and provide insights into seismic risks. By analyzing past earthquakes, scientists can learn more about future seismic activity and improve their ability to predict earthquakes.
Source: https://www.sciencedaily.com/releases/2025/08/250806094127.htm