Ash3d simulation outputs of ash deposition from hypothetical eruptions of Aniakchak (Alaska), Chikurachki (Kurile Islands) and Popocatepétl (Mexico)

We modelled ash deposition from 1,000 randomly selected hypothetical eruption scenarios using the advection-dispersion-sedimentation software Ash3d (Schwaiger et al., 2012) to evaluate the necessary eruption and meteorological parameters needed to transport ash as far as the NEEM coring site (77°27'N 51°3.6'W; 2,000 m above sea level) in Greenland. The same eruption source parameters are applied to each of the three volcanoes of interest: Aniakchak (Alaska), Chikurachki (Kurile Islands) and Popocatepétl (Mexico). We used meteorological data randomly selected from the period 1950 to 2010 drawn from the 2.5 degree NCEP-NCAR Reanalysis II dataset (https://climatedataguide.ucar.edu/climate-data/ncep-reanalysis-r2). Eruption source parameters consisted of randomly selected start times between 1950 and 2010. Eruptive volume was selected from a log-normal distribution between 0.01 and 2.0 km3 (dense rock equivalent). Plume heights were calculated using an empirical best-fit relationship between eruptive volume and plume height (H=25.9 + 6.64 * log10(V), where V is erupted volume in DRE, and H is height above the vent in km) with a random adjustment (Gaussian with μ = 0 km and σ = 2.9 km; Mastin et al., 2020, eq. 3) with a random adjustment (Gaussian with μ = 0 km and σ = 2.9 km; Mastin et al., 2020, eq. 3) within the range 7–30.5 km. Mass eruption rate was calculated from a best-fit relationship with plume height (Mastin et al., 2020, eq. 2) and duration using the mass eruption rate and eruptive volume (see Mastin et al. 2020). The same grain-size distribution (GSD) was used (15% 0.250 mm, 20% 0.125 mm, 40% 0.063 mm, and 25% 0.031 mm) for all simulations. References Mastin, L. G., Van Eaton, A. R., and Schwaiger, H. F.: A probabilistic assessment of tephra-fall hazards at Hanford, Washington, from a future eruption of Mount St. Helens, U.S. Geological Survey Open-File Report 2020–1133, 54 pp., https://doi.org/10.3133/ofr20201133, 2020. Schwaiger, H., Denlinger, R., and Mastin, L. G.: Ash3d: a finite-volume, conservative numerical model for ash transport and tephra deposition, J. Geophys. Res., 117, B04204, doi:10.1029/2011JB008968, 2012.