Scenario-based hazard assessment of Mt Hasan Stratovolcano, Central Anatolia, Türkiye

Abstract Mount Hasan (Türkiye), an active stratovolcano, has had two eruptions during the Holocene and currently exhibits fumarole activities at its summit. Despite its potential hazards, it is not under any monitoring. In a first-of-its-kind study in Türkiye, we utilized VolcFlow and TephraProb (Tephra2) codes to conduct a scenario-based probabilistic hazard assessment and forecast the explosive behavior of Mt Hasan during a volcanic eruption. In our scenario-based hazard assessment study, tephra fall deposits primarily accumulate from plumes dispersing in the NE, E, and SE directions, with occasional accumulation in the SW direction. Eruption source parameters, such as eruption duration, discharged mass, and plume heights, naturally affect the impact rate. The plume heights selected for modeling are (min–max) 5–10 km, 10–15 km, 15–20 km, 20–25 km, and 25–30 km to illustrate related tephra dispersal. All probability and probabilistic isomass maps have been drawn. Volcanic flows were modeled considering the topographic effects using the digital elevation model of the volcano. As a result, an approach was made especially to probable depositional areas and thicknesses. In conclusion, this study identified the areas most likely to be impacted by tephra deposits (fall, flow) given the scenarios applied and developed a comprehensive impact maps. Our findings underscore the urgent need for close monitoring of Mt Hasan.