The 2023 Türkiye-Syria earthquake disaster was exacerbated by an atmospheric river

Strong earthquakes in mountain landscapes can trigger widespread slope failures, initiating chains of multiple hydro-geomorphic hazards. These impacts disrupting ongoing response operations may be amplified by extreme post-seismic precipitation delivered by atmospheric rivers (ARs). However, to our knowledge, cases of ARs following major earthquakes have not been previously documented. Here, we document the combined effects of seismic and precipitation extremes that perturbed the area struck by the February 6, 2023, Türkiye-Syrian earthquakes. Strong ground shaking triggered thousands of landslides, and 36 days later, an exceptionally strong AR delivered up to 183 mm of precipitation in just 20 hours. This extreme precipitation induced additional landslides, debris flows, and flooding, disrupting recovery efforts, affecting temporary settlement areas, and claiming more lives. This cascade of hazards highlights the need to integrate seismic and weather extremes into rapid hazard assessment protocols to enhance disaster preparedness and response. The combination of topography, as a driver for extreme precipitation, and slope instability from seismicity contributed to the compound hazard of post-seismic rainfall-induced landslides, according to an analysis of precipitation and landslide data.