On March 28, 2025, Mandalay, Myanmar was rocked by a devastating magnitude 7.7 earthquake, with shockwaves felt as far away as Thailand, leading to a tragic toll of over 4,900 lives lost.

This catastrophic event originated from the Sagaing Fault, a massive 1,400-km (870-mile) strike-slip boundary that separates the Burma Microplate from the Sunda Plate. It triggered a supershear rupture that swept across 460 km (286 miles), with surface displacements surpassing a staggering 6 meters (20 feet). The earthquake struck with a shallow depth of 10 km (6 miles), unleashing violent shaking (rated at Modified Mercalli Intensity IX) in densely populated urban areas such as Mandalay, Sagaing, and Naypyidaw, while also amplifying seismic energy far away, including Bangkok, Thailand.

An astonishing video shot near Thazi appears to document the moment when two tectonic blocks suddenly shift. In this brief footage, viewers can see the landscape dramatically sliding, vividly illustrating the mechanics of a strike-slip fault.

As the US Geological Survey explains, a fault is a fracture between two blocks of rock that allows them to move relative to each other—either rapidly through earthquakes or slowly in a process known as creep. The notorious San Andreas Fault in California is an example of this type of geological activity.

Despite our era of ubiquitous recording devices, this footage of a fault shift in real-time is unprecedented. It marks a significant moment in geological observation.

The focal mechanism analysis reveals that the earthquake was indeed a result of strike-slip faulting along the Sagaing Fault at a shallow depth. The rupture expanded 75 km (47 miles) to the north, stopping just south of Singu, while a more extensive 420 km (261 miles) rupture traveled south to near Pyu. The most significant slip, exceeding 1 meter (3 feet), occurred between Singu and Oktwin, while areas south of Pyu demonstrated less than 1 meter of movement.

Remarkably, the largest recorded slip was a monumental 4.3 meters (14 feet) between Sagaing and Amarapura. The entire rupture unfolded in just over 80 seconds, with peak seismic activity occurring about 30 seconds post-initiation. The speed of the rupture exceeded the shear wave velocity, officially categorizing this event as a supershear earthquake.