On March 28, 2025, Myanmar experienced a remarkable earthquake measuring 7.7 on the Richter scale. This event not only surprised residents but also seismologists around the world. Unlike typical earthquakes, this one moved at an unprecedented speed, causing widespread devastation.
A recent study published in Science highlights the unique factors behind this fast-moving earthquake. It explores how a combination of geological conditions allowed the fault line to rupture much faster than usual.
The March quake is classified as a “supershear” earthquake. This means the rupture traveled at speeds exceeding three miles per second. Normally, seismic waves travel slower than the rupture itself, but in this case, it was the opposite. Dara E. Goldberg from the U.S. Geological Survey explains this phenomenon, comparing it to breaking the sound barrier in rock: “Supershear earthquakes are like breaking the sound barrier, but in rock.”
This earthquake impacted the country significantly. Many areas experienced intense shaking that severely damaged buildings and infrastructure. The rapid rupture also interacted strangely with the surrounding earth, amplifying the damage in ways not usually observed.
The study reveals three main reasons for the exceptional speed of the rupture. First, the Sagaing Fault’s layout was nearly straight, allowing for a faster, uninterrupted journey of the rupture. Second, a massive amount of stress had built up over decades—since the last major earthquake in 1839—creating a perfect storm for a massive release of energy. Finally, the varying properties of the rocks along the fault line played a role. The differences in rock stiffness and strength caused seismic energy to behave unpredictably, contributing to the rupture’s swift progress.
The implications of supershear earthquakes like this one are significant. They raise new challenges for engineers and urban planners. Traditional earthquake models often underestimate the potential impact of earthquakes like this when predicting damage. Lingsen Meng, a professor at UCLA, highlights this concern, stating that the shock waves from a supershear earthquake can double the intensity of shaking even hundreds of kilometers away.
This highlights an important lesson for disaster preparedness: regions located farther from the fault might experience more severe shaking than those closer. As we study and understand these extraordinary events further, it will allow communities to better prepare for future risks.
For more information about the seismic data and research, you can visit the U.S. Geological Survey and the detailed findings in the journal Science.
