Myanmar Quake Study May Change US Seismic Risk Assessments

Researchers at the University of Southern California Dornsife College of Letters, Arts and Sciences found that simple-looking faults can generate complex earthquakes.

This discovery could fundamentally change how scientists estimate seismic risk for dangerous fault zones in California and other regions worldwide. By understanding how these ruptures behave, officials may be able to better predict the impact of future disasters.

The findings were published in the journal *Science* in May 2026 ^[4]. The study focused on a 7.7-magnitude earthquake ^[1] that struck central Myanmar on March 28, 2025 ^[2]. That event resulted in thousands of deaths ^[3].

Scientists previously believed that faults with simple structures typically produced simpler earthquake ruptures. However, the analysis of the Myanmar event revealed that the structural simplicity of a fault does not necessarily limit the complexity of the resulting quake. This suggests that many fault systems previously categorized as low-risk or predictable may actually pose a greater threat than current models suggest.

The USC-led team used the Myanmar data to challenge existing assumptions about seismic behavior. The research indicates that complex rupture patterns can emerge even when the underlying geology appears straightforward, a realization that has immediate implications for the U.S. West Coast.

California's fault zones are among the most studied in the world, yet the study suggests that current risk gauges may be missing critical variables. If simple faults can produce complex ruptures, the potential for larger, more destructive earthquakes in populated areas may be higher than previously estimated.