3D modeling of the Buhi debris avalanche deposit of Iriga Volcano, Philippines by integrating shallow-seismic reflection and geological data

• The thickness of the Buhi DAD was estimated from shallow seismic profiles.
• The seismic profiles were integrated into 3D geological models of the Buhi DAD.
• Paleotopography of Iriga Volcano was reconstructed.
• Volumes of the collapsed sector and the DAD were calculated from Leapfrog Geo.
• Calculated volumes are higher than estimates of previous works.

Numerical models for simulating volcanic debris avalanches commonly lack a critical initiation parameter, the source volume, which is difficult to estimate without data on the deposit thickness. This, in turn, limits how rheology can be characterized for simulating flow. Leapfrog Geo, a 3D geological modeling software, was used to integrate shallow-seismic reflection profiles with field and borehole data to determine the volume of the Buhi debris avalanche and the pre-collapse structure of Iriga Volcano. Volumes of the deposit calculated in this way are 34–71% larger than previous estimates. This technique may improve models of debris avalanches elsewhere in the world, and more precisely depict landslide runout and lateral extent, thus improving disaster prevention and mitigation for the many cities located near volcanoes.