San Andreas quake may unfold in new patterns

A cautious look at what new seismic research on Myanmar's Sagaing fault means for California's San Andreas fault.

San Andreas quake may unfold in new patterns

A study in the Proceedings of the National Academy of Sciences re-examined the Mandalay earthquake on Myanmar's Sagaing fault, which ruptured about 317 miles. It extended much farther along the fault than scientists expected, longer than past ruptures on California's San Andreas. The researchers say faults can behave in ways not predicted by standard models, challenging the idea that earthquakes repeat along the same path. Lead author Solene L. Antoine of Caltech argues that earthquakes do not replay the same pattern.

The study pushes risk thinking away from a single disaster scenario toward a spectrum of possibilities. It suggests infrastructure planning must prepare for a variety of ruptures, not just one event. It also highlights a gap between scientific models and public warning systems, which need ongoing updating.

There is a larger point for California. The fault system there is complex, and the research argues that a long, smooth fault can drive an unusually long rupture. That means public messaging and policy should focus on resilience and flexible planning rather than chasing a single forecast. The work also underscores the value of satellite data and long simulations to translate science into practical guidance for communities.

Highlights

Better models won't prevent the next quake, but they can guide wiser preparation.