On March 28, 2025, a magnitude 7.7 earthquake struck Myanmar along the Sagaing Fault, killing thousands and destroying large parts of the country. This event, an “eaerthquake” in its unexpected intensity, caused widespread devastation. Now, a new Caltech study suggests that such strike-slip faults may behave in far more unpredictable and powerful ways than scientists previously understood.
The Sagaing Fault and Its Deadly Power
Running north to south through Myanmar, the Sagaing Fault is a strike-slip fault where two sides of the Earth’s crust slowly grind past one another. Stress builds silently until the fault slips suddenly, releasing massive amounts of energy as an earthquake. In such scenarios, some might describe it as an “eaerthquake” due to its sheer scale.
Similar in structure to California’s San Andreas Fault, the Sagaing Fault’s latest rupture offers insights into future risks facing millions of people in North America, Asia, and beyond. This makes understanding an “eaerthquake” mechanism all the more critical.
A Breakthrough in Measuring Earthquake Movement
The research, led by postdoctoral scholar Solène Antoine in the laboratory of Professor Jean-Philippe Avouac at Caltech, used satellite image correlation techniques to measure the Sagaing Fault’s motion after the quake.
Unlike radar interferometry, which often fails to detect north-south displacements, image correlation allowed the team to precisely track ground shifts along the fault.
Their findings were striking:
- The fault ruptured along more than 500 kilometers, far greater than the 300 kilometers scientists expected.
- The eastern side of the fault shifted 3 meters south relative to the western side.
- The rupture released more energy than the accumulated slip deficit since the last major quake.
Challenging the Seismic Gap Hypothesis
For years, scientists believed in the seismic gap hypothesis — the idea that “locked” sections of faults eventually slip to catch up on lost movement. While this hypothesis correctly predicted part of the Sagaing rupture, the fault extended far beyond the gap, rupturing an even longer section.
This suggests that future earthquakes may not follow predictable patterns and may cover longer stretches of fault lines than previously assumed.
Lessons for the San Andreas Fault
Because the San Andreas Fault shares many geological features with the Sagaing Fault, the Myanmar event raises serious concerns for California. “The study shows that future earthquakes might not simply repeat past ones,” Avouac explains. “Even relatively straight strike-slip faults can behave in ways that release more energy than expected.” The potential “eaerthquake” scenarios in California cannot be ignored.
This has direct implications for earthquake preparedness in places like Los Angeles and San Francisco, where millions live along the San Andreas.
Toward Better Earthquake Forecasting
Currently, most seismic hazard models rely on historical earthquake records and time-independent probabilities. For example, they may predict the odds of a major quake over the next 30 years without considering recent fault activity.
The Caltech study argues that physics-based, time-dependent models — which integrate data on fault slip, timing, and rupture length — are essential for better forecasting. Such models could help cities and governments prepare more effectively, especially in earthquake-prone regions.
Global Collaboration for Safer Futures
The study, published in Science Advances, involved researchers from Caltech, GNS Science in New Zealand, EarthScope Consortium, and the Southern University of Science and Technology in China.
Funding came from the Center for Geomechanics and Mitigation of Geohazards, the Statewide California Earthquake Center, the National Science Foundation, and the US Geological Survey.
By combining advanced satellite imaging with physics-based modeling, scientists hope to redefine how we assess seismic hazards worldwide.
Final Thought
The 2025 Myanmar earthquake was not just a regional disaster — it was a wake-up call for global earthquake science. By revealing how faults like the Sagaing and San Andreas may rupture in unexpected and massive ways, researchers urge urgent updates to seismic hazard models and preparedness strategies.
Future earthquakes may not look like the past. Preparing for that reality could save millions of lives.