Probabilistic Landslide Hazard Assessment of the 2023 Türkiye–Syria Earthquake and Subsequent Atmospheric River

On February 6, 2023, a Mw 7.8 and Mw 7.5 earthquake doublet struck along the East Anatolian Fault Zone in Türkiye, triggering over 3,600 coseismic landslides. Roughly a month later, a rare atmospheric river event delivered up to 183 mm of rainfall in just 20 hours to the earthquake impacted region. This extreme precipitation induced additional landslides, debris flows, and flooding.

In our research, we conduct a probabilistic landslide hazard assessment using the open-source Landlab earth surface modeling library, integrating both seismic and climatic drivers. The model incorporates earthquake legacy effects, representing post-seismic slope weakening, and simulates shallow landslide susceptibility using a Monte Carlo implementation of the infinite slope stability theorem informed by remote sensing datasets.

I will present three key analyses: (1) modeling hydrologic response to the AR event and mapping landslide probability with and without earthquake legacy effects; (2) examining how the sequence and combination of extreme events alter landslide hazard; and (3) demonstrating how using historic climate data can effectively replicate post-seismic landslide hazard maps that use real-time data, offering an approach for seasonal hazard forecasting in tectonically active and climate-sensitive regions.