Combined approach to estimate the depth of the magma surface in a shallow conduit at Aso volcano, Japan

Abstract Open-vent volcanoes provide opportunities to perform various methods of observation that can be used study shallow plumbing systems. The depth the magma–air interface in portion conduit as an indicator volcanic activity open-vent volcanoes. Although there are many estimate depth, most them cannot constrain a narrow range due other unknown parameters. To more accurately, we combine two commonly for estimating interface. They consider acoustic resonant frequency and time delay arrivals between seismic infrasound signals explosions. Both have same parameters: sound velocity inside vent. Therefore, these unknowns constrained so both observed explained simultaneously. We use seismo-acoustic data Strombolian explosions recorded vicinity Aso volcano, Japan, 2015. estimated depths velocities 40–200 m 300–680 m/s, respectively. is narrower than previous using only arrivals. However, small amount estimation, rest realistic or velocities. In particular, wide distribution by our simple assumptions. By considering complicated environment explosions, such source positions distributed across whole surface lava pond conduit, estimation. This suggests factor controlling not generally expected. Graphic abstract