Supplementary Materials for Seismic forecasting insights from slip patterns before 2025 and 2023 earthquakes in Myanmar and Türkiye

Despite advances in seismology, forecasting remains inadequate, as seen in the 2025 Mw7.7 Myanmar and 2023 Mw≥7.6 Türkiye earthquakes, which caused over 60,000 deaths. These events ruptured major strike-slip faults forming active plate boundaries: the Sagaing Fault in Myanmar and the East Anatolian Fault in Türkiye. We analyze seismic moment release during the 1,000 days preceding each event and identify both shared and contrasting patterns. The Myanmar earthquake followed a sharp increase in seismic energy release, then ~50 days of quiescence. In Türkiye, a gradual focusing of seismicity preceded the first earthquake, while the second was preceded by ~250 days of quiescence. These differences suggest varying fault properties influence rupture behavior. We propose that fault maturity, segmentation, and aseismic slip behavior may help explain these patterns. Integrating such insights with real-time monitoring can enhance seismic forecasting and improve preparedness in tectonically active regions.