A groundbreaking video of an earthquake has provided the first-ever direct observation of a seismic fault rupturing in a curved path, a phenomenon previously only inferred from geological records.
The footage, captured by a security camera near Thazi, Myanmar, shows the ground tearing apart during a magnitude 7.7 earthquake on March 28. While surface ruptures are a known feature of major quakes, this marks the first time one has been captured on video.
The discovery’s significance was identified by Jesse Kearse, a geophysicist at Kyoto University, who noticed the rupture’s unique trajectory. While scrape marks on fault lines, known as “slickenlines,” have long suggested that such curved movements occur, this was the first time the process was seen in real-time.
Kearse and his colleague, geophysicist Yoshihiro Kaneko, analyzed the footage in detail. They found that the rupture began with a sharp curve, accelerating to a peak velocity of 3.2 meters per second (10.5 feet per second). The ground slipped a total of 2.5 meters (8.2 feet) in just 1.3 seconds before the crack straightened and slowed.
The researchers suggest this curvature is caused by the disparity between stress levels on the fault, which are lower at the Earth’s surface than they are deeper underground. This uneven stress pattern temporarily pushes the rupture off its course. “The curvature holds important information about the dynamics of the rupture,” Kearse said.
Understanding these dynamics can reveal new details about how past earthquakes have unfolded and help scientists improve models for predicting future ground ruptures. The research was published in the journal The Seismic Record.
